The following abstracts are presented as submitted to NASA in response to NRA-01-OSS-02 in May 2001. In the peer review process some proposals may have been reduced in scope or targets. Such changes are not reflected in these abstracts. Proposal ID: C001 Principal Investigator: Welsh, Barry Institution: University of California, Berkeley Proposal Title: A far UV study of high velocity atomic and molecular gas associated with the evolved Shajn 147 SNR We wish to observe high velocity atomic and molecular gas seen in absorption towards two early-type stars lying behind the evolved Shajn 147 SNR. We shall compare the physical and chemical conditions of this disturbed medium with that recently found for the similarly evolved Monoceros Loop SNR and contrast conditions in both these SNRs with that found for the far younger Vela SNR. Topics of particular interest will be the range of ionization present in the high velocity gas clouds, their atomic gas phase abundances and the possibility of detecting high velocity molecular H_2 absorption associated with the expansion of the remnant. Proposal ID: C002 Principal Investigator: Massey, Philip Institution: Lowell Observatory Proposal Title: FUSE Observations of LMC and SMC O3-4 Stars - the Physical Parameters of the Hottest Stars The Far Ultraviolet Explorer provides a fantastic means of advancing our understanding of the physical parameters of the most massive stars. New ground-based optical data has identified a sample of hitherto unknown stars of the earliest spectral types in both Clouds. UV observations with HST are underway, but FUSE data in the FUV provides a much needed complement. With FUV data of O VI lambda 1032 we obtain a much more accurate measurement of stellar wind parameters, allowing us to reliably use the optical nitrogen lines as a independent check on effective temperature. FUV observations of the Ar VI lambda 1000 and Ar VII lambda 1064 will provide additional constraints. We will use the most sophisticated and comprehensive model atmosphere codes including the effects of NLTE line blanketing, stellar wind outflows and spherical extension to analyze the data. Our analysis will constrain the radiative contributions by shocks in the wind, providing information about stellar wind ionization structure, and allowing good determinations of the stellar chemical compositions of the most massive stars in the Clouds. We will also be in a unique position to analyze the interstellar spectrum, and, from our continuum models, determine the extinction from the FUV to the optical. We already have outstanding optical and HSTSTIS data on the most interesting, hottest stars in the SMC and LMC, and with the data that FUSE can provide, we will have the full wavelength coverage needed to do a really comprehensive job. Proposal ID: C007 Principal Investigator: Dinerstein, Harriet Institution: University of Texas, Austin Proposal Title: Radiative Cascade Emission from Molecular and Ionized Gas in Planetary Nebulae We propose to observe diffuse UV emission from electronically-excited H_2 molecules and recombining O^+2 ions in planetary nebulae (PNs). The H_2 observations will complement our Cycle 1 and 2 programs of observing the Lyman and Werner H_2 resonance bands in absorption against the continua of the central stars. In Cycle 3 we will observe the stage of the fluorescence process which immediately follows the photon absorptions, and in turn populates the upper levels of the widely-observed near-infrared transitions such as v1-0 S(1) 2.122 micron. Our FUSE observations will help resolve the on-going controversy over whether photoexcitation (as opposed to shocks) is the main excitation mechanism for the near-infrared lines, test current models for the photoexcitation of H_2 in strong UV fields in general, and enable us to constrain the physical conditions and total mass of H_2 in PNs. If photoexcitation dominates, it is likely that most PNs contain large amounts (several tenths of a solar mass or more) of molecular material, in addition to the ionized gas and possible neutral atomic gas. We will also search for diffuse O II UV emission which is part of the recombination cascade of O^++. Recent studies have shown that optical O II lines belonging to the same radiative cascade are anomalously strong in some PNs, by factors of up to five; taken at face value, these line strengths indicate super-metal-rich abundances in many apparently ordinary PNs. The reason for this anomaly is not understood, but it casts doubt on our present understanding of atomic processes and elemental abundances in nebulae. These proposed FUSE observations will test current calculations of the O II recombination spectrum and address this recalcitrant problem from a new perspective. Proposal ID: C008 Principal Investigator: Hoard, Donald W. Institution: Cerro Tololo Inter-American Observatory Proposal Title: Mass Transfer in the Interacting Binary White Dwarf AM Canum Venaticorum AM Canum Venaticorum is the prototype of the interacting binary white dwarf (IBWD) class of cataclysmic variable (CV). Unlike normal CVs, in which the mass donor is a hydrogen-burning late main sequence star, the donor in an IBWD is a helium white dwarf (WD). Mass transfer and accretion play important roles in a wide range of astrophysical scenarios, and IBWDs provide the opportunity to study a unique, relatively unexplored form of mass transfer with implications for our understanding of degenerate matter and mass transfer in general. We propose to observe AM CVn with FUSE to obtain far-UV spectra folded into multiple orbital phase bins. We will achieve several scientific goals with this observation, including (1) obtaining the first far-UV spectrum of an IBWD, which will yield abundance and excitation information and provide far-UV constraints for the devlopment of IBWD accretion disk models; 2) via high spectral resolution and high SN, thoroughly and conclusively exploring the complex line profiles hinted at by past optical and near-UV studies; 3) assessing the presence, composition, temperature, etc., of possible circumbinary material, which has potentially important consequences for the secular evolution of CVs; and 4) investigating the physical structure of AM CVn with phase-resolved spectra as it rotates in its orbit -- such phase-resolved spectral studies of CVs in the optical and near-UV have been irreplaceable sources of structural information about these binary stars. We will carry this forward to the far-UV with our FUSE observations of AM CVn. Proposal ID: C010 Principal Investigator: Wood, Janet H. Institution: San Diego State University Proposal Title: Flares, Magnetic Reconnections and Accretion Disk Viscosity Accretion disks are invoked to explain a host of astrophysical phenomena, from protostellar objects to AGN. And yet the mechanism allowing accretion disks to operate are completely unknown. This proposal seeks to observe the smoking gun signature of magnetically--driven viscosity in accretion disks. Magnetically--induced viscosity is a plausible and generally accepted hypothesis (for aesthetic reasons), but it is completely untested. Determining the cause of accretion disk viscosity is of major significance to all accretion--disk powered systems (e.g. CVs, X--ray binaries, AGN and protostellar disks). These data will also firmly establish the importance of magnetic fields in accretion disks. Because of its known flaring properites, we will observe the accretion disk in EM Cyg with FUSE simultaneously with our HST (STISFUV) and CHANDRA time which has already been allocated. This will allow the unambiguous detection of accretion disk magnetic reconnection flares. Proposal ID: C011 Principal Investigator: Evans, Nancy Remage Institution: Smithsonian Astrophysical Observatory Proposal Title: The Mass of the Classical Cepheid S Mus A measured mass of a classical Cepheid provides a unique test of evolutionary calculations in evolved stars because it is combined with a precisely known luminosity. The quantitative understanding of Cepheids reinforces the key role they play in determining extragalactic distances. IUE, HST, and Voyager observations have now made possible observational determination of masses for several Cepheids in binary systems. A FUSE spectrum of the hot companion of the Cepheid S Mus A is the key to a significantly improved accuracy for the mass, which is particularly important because S Mus A is the Cepheid with the largest measured mass. A FUSE spectrum is necessary because this wavelength range is particularly sensitive to temperature at the spectral type of the companion (B3 V), and the high resolution of FUSE is required to correct for the H_2 absorption accurately. The spectral type or temperature (and the mass inferred from it) will be combined with the orbital velocity amplitude of the companion from HST GHRS echelle spectra, and the orbital velocity amplitude of the Cepheid from the ground-based orbit to determine the mass of the Cepheid. By including the FUSE data, the uncertainty in the mass of the Cepheid will be reduced from the current value of 12 percent to 7 percent. This will make it the most accurate Cepheid mass currently available and provide the strongest constraint on evolutionary calculations. Proposal ID: C017 Principal Investigator: Walter, Frederick M. Institution: SUNY Stony Brook Proposal Title: The early evolution of the circumstellar environment of solar-like stars The UV spectra of the youngest cool stars, the classical T Tauri stars, are dominated by emission lines of molecular hydrogen (H_2), yet within a few million years the H_2 lines fade and the spectra take on the characteristics of the solar chromosphere and transition region. By the end of AO2, spectra of five T Tauri stars and of a few zero-age main sequence stars will be in the FUSE archives. Here we propose to obtain spectra of two low mass pre-main sequence stars to study the earliest evolution of the stellar transition regions, and to look for residual fluoresced circumstellar gas. The targets are naked or weak T Tauri stars, with ages of 10^6 years but no evidence for circumstellar material. This sample fills the observational gap between the T Tauri stars and the ZAMS stars like AB Dor. We have far-UV and X-ray spectra of these stars, and will use these together with the FUSE spectra to examine the atmosphere and circumstellar environments of the youngest non-accreting cool stars. Proposal ID: C018 Principal Investigator: Walter, Frederick M. Institution: SUNY Stony Brook Proposal Title: The Peculiar B Star HD 28867E We propose to observe the young visual pair of B9 stars HD 28867. The eastern component is one of the strongest X-ray sources in the Tau-Aur star forming region, has a near-IR excess, and a Lithium absorption line, all of which are unexpected in a B9 star. The FUSE spectrum, although the sum of the light from the two B stars, will be used to search for anomalous spectral features, including H_2 absorption from circumstellar material and OVI emission from a possible cool companion. We seek to determine whether the near-IR excess and cool absorption lines arise in a cool companion or in an edge-on disk. FUSE is more sensitive to emission from a cool companion of a hot star than is HST. Proposal ID: C019 Principal Investigator: Brandt, William N. Institution: The Pennsylvania State University Proposal Title: Monitoring the Variable UV Absorption in NGC4051 with FUSE We propose two FUSE observations of the bright, nearby Narrow-Line Seyfert 1 galaxy NGC 4051. By studying the variability of the far-UV absorption lines, we aim to constrain the dynamical evolution, physical properties (density and ionization parameter), location, and extent of the absorbing gas. FUSE observations of the O VI 1032, 1038 A lines will bridge the gap in ionization potential between the current HST and Chandra spectra, enabling us to identify UV/X-ray absorption system counterparts. The C III 977 A line and higher-order Lyman lines (Lyman beta and up) will fill in key gaps in our understanding of the ionization properties of many of the UV absorption systems. NGC 4051 is an ideal candidate for this study and will serve as an archetype for characterizing the absorption in low-luminosity Seyferts. Proposal ID: C020 Principal Investigator: Dreizler, Stefan Institution: Universitat Tubingen Proposal Title: Time resolved spectroscopy of the sdB variable PG1605+072 The recent discovery of radial and nonradial mode pulsations in more than 20 sdB stars make them primary targets for asteroseismology to probe their internal structure and discern their evolutionary status; the latter is crucial for reasons as diverse as understanding the late stages of stellar evolution and the calibration of the observed ultraviolet upturn in giant elliptical galaxies as an age indicator. Central to any asteroseismological study is an identification of the pulsation modes. Photometric studies have failed to identify modes from optical light curves. Line profile and flux variations in the far ultraviolet offer a promising way to disentangle the pulsation modes by comparison with detailed model predictions. PG1605+072 is an outstanding target among the sdB variables because it displays the richest period spectrum (>50 pulsation periods), largest amplitudes and longest periods, which makes it the primary target for a spectroscopic FUV study. Proposal ID: C022 Principal Investigator: Harper, Graham M. Institution: University of Colorado at Boulder Proposal Title: Chromospheric Activity in Population II Giants One of the mysteries of Population II stars is that they still show chromospheric emission despite their great age. The global dynamo which was active during their main-sequence lifetimes is expected to become extremely weak through magnetic rotational braking. The nature of the observed emission is not understood; although acoustic shock waves might provide the heating, acoustic waves are not predicted to drive the observed mass loss - which in turn requires the dissipation of magnetohydrodynamic waves. We propose to observe the stellar H Lyman beta emission wings and the fluorescent FeII and H_2 emission from one of the brightest, metal poor, Population II stars. These FUSE diagnostics, when combined with existing UV and optical spectra, will be used to determine the major radiative cooling channels and establish reliable chromospheric cooling rates. These will then be compared to theoretical predictions from hydrodynamic models which have been proposed to generate the basal heating. By examining metal deficient stars we can extend the age-metallicity parameter space and provide a stringent test of the hypothesis that hydrodynamics alone is responsible for the observed chromospheric heating. The likely alternative is some combination of small-scale magnetic turbulence and acoustic shock heating. This target will complement the spectra of the mildly metal deficient giant alpha Boo and will be a invaluable and unique addition to the FUSE Archive. Proposal ID: C023 Principal Investigator: Harper, Graham M. Institution: University of Colorado Proposal Title: Evolved Late-Type Star FUV Spectra Mass Loss & Fluorescence We propose a detailed analysis of the FUV photoionizing radiation that provides crucial input physics for mass loss studies, e.g. observations of the flux below 1044 A will allow us to constrain the CaII CaIII balance and make significant progress beyond previous optical studies on stellar mass loss, and circumstellar photochemistry. Our targets provide the spectral-type coverage required to unravel the CaII CaIII balance as the mass-loss rates increase by over three orders of magnitude from K5III to M5III. We also seek to determine the relationship between the FUV radiation field and other more abundant (e.g., archival HST or IUE) UV diagnostics. This will allow us to achieve our goal of empirically estimating the FUV radiation field for the vast majority of stars which are too faint to be observed with FUSE, and to improve upon their uncertain mass-loss rates. The H Ly beta profile provides crucial information on the excitation and ionization of hydrogen. H Ly beta also causes fluorescence at longer UV wavelengths. We hope to establish directly the relationship between H Ly beta and the fluorescent emission in the UV. We propose deep exposures of beta Gru (M4.5III), beta Peg (M2.5II-III), alpha Cet (M1.5III), beta And (M0III) and lambda Vel (K4Ib) that are well studied in other spectral regions and are important for the study of mass loss. These spectra will provide a valuable complement to the spectral types and evolutionary phases of the GTO targets and our Cycle 1 and 2 targets. Proposal ID: C026 Principal Investigator: Lanz, Thierry Institution: University of Maryland Proposal Title: FUSE Observations of Key DBA and DAB White Dwarfs We propose FUSE observations of three key white dwarfs having hybrid helium and hydrogen spectra the DBA and DAB stars. These stars are relatively rare, but may hold the key for understanding the chemical evolution of white dwarf atmospheres along the cooling sequence, more particularly the so-called DB gap. One possible explanation for these white dwarfs with mixed atmospheres is convective dredge up, where convection mixes the hydrogen and helium layers. Potentially other elements such as carbon and nitrogen may also be dredged up. Strong C and N lines are present in the FUSE band, and can serve as sensitive measures of the presence of these elements. Alternatively, some DAB stars have been found to be spectral composites consisting of DA and DB double degenerate binary systems. The FUSE band is uniquely sensitive to the spectral energy distribution of stars in the 20,000 to 30,000 K range and will make it possible to distinguish two white dwarfs, even if their effective temperatures are similar. Other possible models, including interstellar accretion, stratified atmospheres and surface inhomogeneities, can be tested with FUSE spectroscopy. Proposal ID: C027 Principal Investigator: Ferland, Gary Institution: University of Kentucky Proposal Title: Orions Veil, Magnetic Bomb or Gossamer Sheet Orions veil is a layer of largely neutral gas seen in absorption against the Trapezium stars and the background HII region. Many of its properties are known, including its rather high magnetic field strength. Yet two important issues remain. The first concerns the magnetic field. Is the field in equipartition with turbulent motions in the veil, as is commonly assumed in the ISM If so, the veil must be quite dense and exceptionally thin. If the veil is less dense and thicker, then the magnetic field dramatically dominates its energetics. Neither choice is intuitive; gas density is the key to deciding between them. The second issue is the very low molecular hydrogen fraction, entirely unexpected from equilibrium models. Are previous observations wrong Or is the veil completely out of chemical equilibrium We will use FUSE to measure absorption, including that of molecular hydrogen, along four lines of sight through the veil. These data, interpreted in light of our photoionization models, will reveal the density of the veil. They will also reveal its molecular hydrogen column. These results will have important applications to physical conditions in the Orion region and in the general ISM. Proposal ID: C029 Principal Investigator: Raymond, John Institution: CfA Proposal Title: A Face-On Collisionless Shock in the Cygnus Loop Collisionless shock waves in interstellar plasmas heat different particle species to different temperatures, and they accelerate some particles into a non-thermal power law distribution. UV and optical observations in the past few years have strongly constrained the ratios of electron, proton and heavy ion temperatures in a few SNRs. We propose to measure the OVI emission line profile in the face-on shock near the center of the Cygnus Loop in order to constrain the kinetic temperature of oxygen and to constrain the fraction of shock energy going into cosmic rays. Analysis of this 350-400 km shock is needed for comparison with the 2300 kms^-1 shock in SN1006 to explore the velocity dependence of thermal equilibration and cosmic ray acceleration. Proposal ID: C030 Principal Investigator: Sabra, Bassem M. Institution: University of Florida Proposal Title: The Physics of AAL Quasars We propose FUSE observations of the two nearby radio-loud quasars PKS2135-14 and PKS2251+11 to search primarily for Ne+8 lambda 770, 780 associated absorption lines (AALs). These two quasars lie at redshifts (z equals 0.2 and 0.3, respectively) which place Ne+8 lambda 770, 780 in the bandpass of FUSE. Detection of Ne+8 absorption, as well as absorption in other high-ionization FUV lines, will allow us to place tighter constraints on the total column densities, the overall levels of ionization, and the quasar--AAL relationship. We will use these data in conjunction with existing HST spectra to measure - constrain column densities of a wide range of ions, quantify the relationship to X-ray absorption, study the outflow dynamics, measure elemental abundances, and explore implications for galaxy evolution. The proposed observations will be essential contributions to a larger project involving HST spectra and images, new ground-based data, and X-ray observations with Chandra and or XMM of these and other similar quasars. Proposal ID: C034 Principal Investigator: Tovmassian, Gaghik Institution: Instituto de Astronomia, Universidad Nacional {Autonoma de Mexico} Proposal Title: Probing The Most Oxygen-Poor Halo Planetary Nebula We propose to observe the planetary nebula PNG135.9+55.9, which we recently discovered in the Galactic halo. It is by far the most oxygen-poor planetary nebula known today, with an OH ratio about 1 to 500 of solar. The study of this extreme object is particularly important for probing the early chemical history of our galaxy, for studying the mixing processes in stellar interiors at extremely low metallicities, and for providing an independent determination of the pregalactic helium abundance. Our ground-based observations give an Ne to O abundance ratio of about 0.7, possibly indicating the occurence of unusual mixing mechanisms, and He to H of 0.074 +- 0.02. The proposed FUSE observations will allow us to determine the abundances of C and N, which are essential to understand the causes of the abundance pattern observed in this object. They will also allow us to put stringent limits upon the pregalactic helium abundance using a method radically different from that based upon metal-poor extragalactic HII regions. Proposal ID: C036 Principal Investigator: Benjamin, Robert A. Institution: University of Wisconsin-Madison Proposal Title: Molecular Gas In The Disk-Halo Interface We propose to obtain FUSE observations of one of the most unusual molecular clouds known in the Galaxy (IVC 135+54-45 or IV21). This translucent molecular cloud is located in the low galactic halo, and is only one of three molecular clouds known to have a velocity not consistent with galactic rotation. It may arise from either vertical Galactic circulation or from extragalactic infall. Our observations will allow us for the first time to measure critical parameters for the cloud abundances, densities, pressures, and search for time-dependent effects in what must certainly be a dynamically evolving situation. The information obtained here will allow us to link dynamical models of cloud infall to time-dependent chemical changes. These observations will serve as a useful comparison to studies of physical conditions in translucent clouds in the Galactic disk, and may allow us to determine the distance to OVI bearing gas seen in this direction towards an extragalactic object. Proposal ID: C037 Principal Investigator: Benjamin, Robert A. Institution: University of Wisconsin Proposal Title: A search for OVI emission from high-velocity clouds We propose to observe two objects, NGC 7714 and PG 1626+544, using the MDRS to obtain a high quality absorption spectrum of OVI while simultaneously using the LWRS to search for diffuse OVI emission from high velocity clouds. Relatively brief exposures for these targets already show high column density, high velocity OVI absorption associated with the Magellanic Stream and complex C, respectively. They are thus the most likely directions for the detection of high-velocity OVI emission. The combination of the high quality OVI absorption spectra together with measurements of diffuse OVI emission will allow a direct measurement of the density and pressure in the interaction region and provide straightforward constraints on the density and velocity structure of the gaseous Galactic halo. This, in turn, will constrain models of mass, energy, and angular momentum loss for the Galactic interstellar medium. The absorption spectra will also be used to constrain the abundances in the Magellanic Stream and complexC. Proposal ID: C038 Principal Investigator: Simon, Theodore Institution: University of Hawaii Proposal Title: Seeing Double - Do the X-Ray Luminous Early A Stars Have Active Binary Companions Main sequence A stars have a very shallow outer convection zone and are not expected to shine brightly in either UV chromospheric emission lines or coronal X rays. Nonetheless, a small handful of early A stars were detected as strong sources of soft X rays during the ROSAT All Sky Survey, in some instances at luminosities above L_x > 1 x 10^30 erg s^-1. In certain of these cases, the X-ray emission is suspected to come not from the A stars themselves, but from late-type companions, which were not resolved in the wide beam of ROSAT. We propose to test this hypothesis with UV spectra from FUSE in the wavelength region below Lyman alpha, where we can achieve high contrast between the chromospheric emission and the photospheric light of the primary. For a given measured X-ray flux, the C III 977 feature, in particular, is expected to be faint and narrow if a late-type dwarf is present, but strong and broad if the emission originates from the A star itself. A definitive answer can thus be obtained with very short snapshot exposures appropriate for a broad survey. Proposal ID: C041 Principal Investigator: Szkody, Paula Institution: University of Washington Proposal Title: A Study of the Inner Disk and Hot White Dwarf in Novalikes Above the Period Gap While IUE and HST provide ideal information on the disks and white dwarfs present in Cataclysmic Variables (CVs)in the temperature range of 10,000-20,000K, the importance of FUSE lies in its ability to study the hottest white dwarfs and the innermost areas of their surrounding accretion disks. This high temperature regime involves the higher accretion rate system that are located above the period gap at periods longer than 3 hours. For our study, we have chosen the two novalike systems V794 Aql and YY Dra for which IUE HST studies show hot white dwarfs or disks. V794 Aql does not show outbursts while YY Dra has a magnetic white dwarf and shows dwarf novae outbursts. A comparison of the disks, white dwarfs in these 2 systems with the low accretion rate dwarf nova system U Gem that FUSE observed in Cycle 1 will provide important constraints on the accretion limits for disk instability outbursts. We will use our BINSYN model code to confirm the hot temperature of the white dwarf in YY Dra and the disruption radius of its disk due to the magnetic field, and the high temperature and accretion rate for V794 Aql which lies above the limit for dwarf nova outbursts. Proposal ID: C043 Principal Investigator: Morrison, Nancy D. Institution: The University of Toledo Proposal Title: The Stellar Wind of Deneb (Alpha Cygni, A2 Ia) The spectrum in the 1100--1187 A region of Deneb (Alpha Cyg, A2 Ia), the only star of its type observable by FUSE, will be recorded, along with that of a comparison object with negligible mass loss, probably eta Leo (A0 Ib). Deneb is a massive star that is evolving toward the red supergiant phase and will finish its life with a supernova explosion. In such stars, radiatively-driven mass loss is sufficient to affect later evolution, yet our knowledge of their mass-loss rates is only approximate. The observations will be analyzed by reference to a grid of spherical, expanding, non-LTE, metal-line-blanketed, unified model atmospheres. The ultraviolet spectrum of Deneb is heavily blanketed with absorption lines that are Doppler shifted and broadened by virtue of being formed in the wind. While the overall flux level will be sensitive to the input values of color excess and effective temperature, the strengths and shapes of the spectral lines are expected to be sensitive to the mass-loss rate. In addition, the region to be observed contains the shifted resonance line FeIII lambda 1122, which will be diagnostic of the ionization balance of Fe in the wind. Incorporating the FUSE spectrum into the model-atmosphere analysis will refine our understanding of the outer atmosphere of this important object, better determine its mass-loss rate, and constrain the theory of the evolution of massive stars. Proposal ID: C046 Principal Investigator: Provencal, Judith Institution: University of Delaware Proposal Title: The Temperature Scale and Chemical Composition of DB White Dwarfs The key to understanding main sequence evolution is hidden in the detailed knowledge of the interiors of white dwarfs. We find structural differences among the two major groups of white dwarfs (hydrogen (DA) vs helium (DB) photospheres) that demand differences in origin not clearly understood by our current models. Our conclusions concerning the differences between DAs and DBs rests on the asteroseismological models of GD358, the brightest known DB variable. These models include 2 critical assumptions 1) an effective temperature of 25,000 K and 2) efficient convection. These two assumptions are inseparably linked. Small changes in temperature will result in changes in model convection zones. Surprisingly, we do not know the temperature of any hot DB to within 1000 K. GD358 itself gives two discordant results ranging from 25,000 to 27,000 K. In addition, HST spectra of DBs reveal surprising detections of CII (1335 A) and a hydrogen abundance three orders of magnitude below expected limits. We propose FUSE observations of GD358 and selected DBs to pin down the DB temperature scale and to investigate surface chemical compositions. Proposal ID: C048 Principal Investigator: Heckman, Timothy Institution: Johns Hopkins University Proposal Title: A UV Spectroscopic Survey of Starburst Galaxies Starbursts are a significant component of the present-day universe, and offer unique laboratories for studying the processes that have regulated the formation and evolution of galaxies and the IGM. We propose to use FUSE to obtain high-quality (SN 8) spectra of 5 powerful starbursts with complementary HST STIS long-slit spectra at longer UV wavelengths. When combined with existing and scheduled STIS+FUSE observations of other starbursts, this sample will allow us to document the properties of the stellar population and interstellar medium in a representative sample that essentially spans the entire range in luminosity (10^8 to 10^12L_sun) and metallicity (0.02 to 2.5 times solar) seen in local and high-z starbursts. The FUSE data will be especially valuable to study 1) the coronal-phase gas that may dominate the energetics of starburst-driven superwinds, 2) the escape of ionizing radiation from starbursts, 3) the H_2 that fuels the star-formation, 4) the starburst dust-attenuation law in the unexplored FUV window, and 5) the stellar content of the starburst (thereby probing the IMF and burst history). Proposal ID: C049 Principal Investigator: Pellerin, Anne Institution: Universite Laval Proposal Title: Young Stellar Populations in Nuclear Starbursts and AGNs We propose to observe two Seyfert 2 galaxies (NGC5135 and NGC1667) and one nuclear starburst galaxy (NGC2718) as part of a study on the starburst-AGN connection. Recent studies has shown the presence of young stellar populations in Seyfert 2 galaxies, suggesting an evolutionary link between nuclear starbursts and AGNs. With our new far-UV spectral evolutionary synthesis code, which make uses of a library of FUSE hot star spectra, we will characterize the young stellar populations observed in AGNs and nuclear starbursts. The far-UV spectral range offers the possibility to directly study the wind signatures from hot stars, which are sensitive to the stellar temperature, luminosity class, and metallicity. The high spectral resolution of FUSE will allow us to collect accurate results on the physical properties of young stellar populations (age, metallicity, stellar masses, initial mass functions, and star formation rates). Combined with optical data these properties will allow us to establish direct links between nuclear starbursts and AGNs. Proposal ID: C050 Principal Investigator: Burleigh, Matt Institution: University of Leicester Proposal Title: The white dwarf companions of late-type B stars We propose to observe the late-type B stars theta Hya and 16 Dra in order to spectroscopically resolve their hot white dwarf companions. Far-UV spectroscopy with Voyager I has already shown that the B star fluxes die at around 1000A, allowing us to observe the uncontaminated white dwarf spectra. These degenerates will have evolved from high mass progenitors and are expected to possess masses well in excess of the mean for white dwarfs in general. The increased sensitivity and resolution of FUSE will allow us to tightly constrain the degenerate stars fundamental parameters (T_eff, log g and mass) through matching model atmospheres to the observed H Lyman absorption lines. These objects can then be used to investigate the high mass end of the white dwarf initial-final mass relation and mass-radius relations. Proposal ID: C051 Principal Investigator: Blair, William P. Institution: Johns Hopkins University Proposal Title: Kinematics and Composition of O-rich Material in Puppis A Very few examples of enriched debris from supernova explosions are available for observation in the far-UV, where unique ionization and chemical abundance diagnostics exist. We propose here to study the kinematics and abundances of two oxygen-rich ejecta knots in the galactic supernova remnant Puppis A. Observations of the outer shell of Puppis A with HUT and in Cycle 2 with FUSE have demonstrated that, even with moderate foreground extinction, the filaments in Puppis A are accessible in the 900 - 1200 A region. These will be the first FUV observations of the O-rich ejecta in Puppis A, and will constrain the abundances of carbon, neon, and possibly sulfur relative to oxygen. In particular, the abundance of C :O is an important diagnostic of the mass of the precursor star. The high resolution of FUSE is crucial for assessing the impact of overlying absorption on the observed line intensities, and thus modeling the relative line strengths and abundances. Proposal ID: C052 Principal Investigator: Blair, William P. Institution: Johns Hopkins University Proposal Title: Absorption-Emission Line Study of the Northeast Cygnus Loop We will observe a star behind the Cygnus Loop supernova remnant to study the line-of-sight interstellar medium structures toward and through this prototypical remnant. In particular, a sdO star identified from Ultraviolet Imaging Telescope UV imaging lies behind the bright NE Cygnus Loop filaments and is the first UV background source known for the Cygnus Loop. We will observe this star as well as the directly adjacent optically-emitting filaments, making a combined emission-absorption line study of the region possible. These two nearly complementary ways of studying the same region will provide the most detailed look to date at the workings of the Cygnus Loop blast wave as it encounters an interstellar cloud. Proposal ID: C053 Principal Investigator: Barstow, Martin A. Institution: University of Leicester Proposal Title: The mass distribution of white dwarfs in cataclysmic variables We propose to observe a sample of cataclymic variables during the low state in their emission, to obtain direct far-UV spectra of the unobscured white dwarf components. From these spectra we will be able to systematically determine T_eff and g for each star and, in conjunction with the theoretical white dwarf mass-radius relation, obtain accurate measurements of their masses and radii. Many of our targets are double line spectroscopic binaries, providing K1, K2, gamma and i. Thus a knowledge of the primary mass will yield the secondary mass. Systematic knowledge of the CV white dwarf mass distribution is essential for understanding the origin and evolution of CVs, determining whether or not they do pass through a period of common envelope evolution and considering the effects of past nova outbursts. In addition, we will use the FUSE spectra to search for photospheric heavy element absorption features from which we can measure element abundances. Of particular importance are the C and N abundance which can reveal an earlier phase of thermal-timescale accretion. Proposal ID: C055 Principal Investigator: Sankrit, Ravi Institution: The Johns Hopkins University Proposal Title: The Distribution of Shock Velocities in N49 - a Bright Supernova Remnant in the LMC Supernova remnants in the Magellanic Clouds have little foreground extinction and can be observed in the ultraviolet. We propose to use FUSE to observe the brightest optical LMC remnant - N49. We will study the distribution and kinematics of the hot, O VI emitting component, and compare it with the lower ionization C III emitting gas. The shock in N49 is impacting a molecular cloud in the southeast resulting in bright filaments. In the west, the pre-shock medium has a lower density and the remnant is fainter. Comparison of FUSE observations of the southeast, northwest and southwest regions will allow us to examine the global shock-ISM interaction and gain insight into how remnants affect their surroundings. We also propose to examine a filament along the southeast rim at higher spectral resolution in order to more sharply constrain the shock properties in that region. Proposal ID: C056 Principal Investigator: Bianchi, Luciana Institution: The Johns Hopkins University Proposal Title: Central Stars of Planetary Nebulae in the Small Magellanic Cloud We propose to observe with FUSE four Planetary Nebulae in the Small Magellanic Cloud, selected from a sample studied with HST UV and optical spectra. The flux is dominated by nebular continuum emission in the HST UV range. Instead, the far-UV spectrum will provide a direct measurement of the stellar continuum, enabling a better estimate of stellar temperature and absolute luminosity, useful to refine post-AGB evolution at low metallicity and nebular ionization modeling. The FUSE spectra will also contain several lines from the central star, that will provide accurate measurements of the wind terminal velocity and mass loss rate. These parameters are important to model the nebular dynamics, and to understand the central stars properties and evolution. Theoretically, the mass loss and several aspects of the post-AGB evolution strongly depend on metallicity, and so does the yield of processed material. Therefore, it is very important to provide observational constraints in different environments. The proposed SMC objects represent an extremely low metallicity case that can be observed by FUSE. We will compare results with similar objects observed by us in the Milky Way (Cycle 1) and in the LMC (Cycle 2), and with new detailed post-AGB calculations (e.g. Marigo et al. 2001). Additionally, the H_2 transitions in the FUSE range provide a powerful way to measure the circumstellar molecular gas, which - added to the mass of the central star, and of the ionized shell previously determined, will allow us to test theoretical initial-final mass relations. The far-UV data will be a unique contribution to constrain the properties of these objects, which are effectively at a single, unambiguous distance. Proposal ID: C057 Principal Investigator: Murphy, Edward M. Institution: University of Virginia Proposal Title: Observations of O VI Emission in the Halo of NGC 4631 We propose to use FUSE to determine the extent and kinematics of OVI emission from hot, cooling gas in the halo of the well studied, edge-on spiral galaxy NGC4631. In FUSE Cycle 1 we obtained two 20 ksec exposures of NGC4631 that both clearly show OVI emission in the halo of the galaxy toward a ROSAT soft X-ray hotspot (NGC4631-A) and in the middle of an H-alpha feature (NGC4631-B) that has been interpreted as a chimney immediately below the hotspot. We would like to obtain measurements along additional sightlines to determine if the hot OVI halo is broadly distributed or whether it is associated only with the localized outflow of hot gas from the chimney hotspot feature. The observations should allow us to determine the total cooling rate of the halo gas which can be compared with the mechanical input energy from supernovae. We should also be able to determine the scale height of the OVI gas and will compare the distribution and kinematics of this transition temperature gas with hotter gas T about 1-3x10^6 K) as revealed by ROSAT and Chandra. We have selected 6 positions in the halo of NGC4631 for exposures of 20-40 ksec each (190 ksec total). Proposal ID: C058 Principal Investigator: Hutchings, John B. Institution: NRC of Canada Proposal Title: O stars in M33 The brightest OB stars in more distant local group galaxies are reachable with FUSE, and a few have been observed. This proposal is to increase the sample to include different locations within M33, to obtain a global comparison of the young stellar populations and ISM in the different galaxy environments. Our earlier work indicates that there are differences in stellar winds and the interstellar extinction and absorption that must relate to the star-formation histories of local group galaxies. Proposal ID: C060 Principal Investigator: Froning, Cynthia Institution: Space Telescope Science Institute Proposal Title: AM CVn Stars - Structure and Evolution of Ultra-Short Period Interacting Binaries AM CVn stars are double degenerate interacting binary systems in which a low mass (about 0.03 M_sun) white dwarf (WD) fills its Roche lobe and transfers mass to another WD via an accretion disk. They are characterized primarily by their helium-rich hydrogen-deficient) spectra, ultra-short orbital periods, and multiplicity of highly variable periodicities. The study of AM CVn stars allows us to probe an alternate, double common-envelope, route of binary evolution and test the influence of varying abundances and physical scales on the physics of accretion and outflows in disk-accreting systems. We propose FUSE observations of the two brightest AM CVn stars, AM CVn itself and EC 15330--1403. These objects are believed to be in a permanent outburst state their accretion disks are hot, viscous, and in a steady-state. Our goals are a) to isolate the relative contributions of the mass-accreting WD star and the accretion disk to the UV continuum; b) to characterize the structure of the small, He-dominated disks; and c) to solve the puzzle of the origin of the UV spectral lines and nature of the winds in AM CVn binaries. With these results in hand we will be able to contrast the properties of more normal, H-dominated disk systems with those of AM CVn systems. Proposal ID: C063 Principal Investigator: Bregman, Joel Institution: University of Michigan Proposal Title: Is Gas Really Cooling in Cluster Cooling Flows Recent X-ray observations of the gas in galaxy clusters have failed to resolve the issue of whether cooling flows are present. However, our FUSE detections of OVI emission in several individual elliptical galaxies demonstrate the existence of cooling flows in these systems, which are cousins to the galaxy cluster cooling flows. The OVI doublet is a powerful diagnostic of gas that is cooling through the 10^5.5 K range, and here we propose to use it to determine if gas is cooling down from the ambient cluster temperature (T > 10^7.3 K) as predicted by the cooling flow model. Our strategy is to observe some of the nearest cooling flow clusters - two ordinary clusters that are representative of the class; and the Perseus cluster, which has the best X-ray evidence for a cooling flow. These observations will either confirm the presence of cluster cooling flows or rule out their existence once and for all. Proposal ID: C064 Principal Investigator: Bregman, Joel Institution: University of Michigan Proposal Title: The Flow Velocities in Elliptical Galaxy Cooling Flows The cooling flow model of elliptical galaxies predicts the rate at which gas cools from 10^7 K to a neutral or warm atomic phase, and as the gas passes through 3x10^5 K, it will produce OVI line emission. This high luminosity OVI emission has now been detected by FUSE in an observation of the classic cooling flow elliptical NGC 4636, where the line emission implies a cooling rate of 0.4 M_sun yr^-1, the same as the value predicted from the model. The model also predicts the inflow speed of the gas, which will be reflected in the line width. We observe the OVI lines to be relatively narrow, already ruling out a variety of models, yet the analysis is compromised by spectral degradation due to the use of the large aperture when observing a diffuse object. Therefore, we propose observations with the medium aperture that will accurately measure the line width and critically test whether the gas is flowing as predicted. Furthermore, each inflow model has a distinct radial distribution, so our observations of the joint predictions of OVI line width and spatial distribution will be an extremely demanding test of the model. Proposal ID: C067 Principal Investigator: Linsky, Jeffrey L. Institution: University of Colorado Proposal Title: Fluorescence and Excitation of Molecular Hydrogen in the Circumstellar Environment of PMS Stars TW Hya will likely have the richest and best exposed far-UV spectrum of any member of the important class of classical T Tauri stars (CTTS) because of its uniquely low extinction (A_v approx. 0.0), the face-on geometry of its disk that minimizes local extinction, absence of a local molecular cloud, and 50 pc distance (the closest for a CTTS). We request a deep exposure of TW Hya to improve the model for H_2 fluorescence (primarily by Lyman-alpha) as demonstrated by our analysis of the very rich H_2 emission line spectrum in the 1170-1600 A range seen in HSTSTIS echelle data. Since the FUSE band includes H_2 emission lines pumped from different rovibrational states in the ground electronic system, including much lower energy states than are sampled by STIS, we can study the population of rovibrational states within the ground electronic state, search for other fluorescent channels, infer the shape of the stellar Lyman-alpha line, study possible excitation mechanisms, and derive a lower limit for the amount of H_2 that is located in the stellar disk. In a short (2.1 ks) test spectrum of TW Hya the probable detection of the two H_2 emission lines demonstrates the feasibility of our program. The requested spectrum will also provide excellent profiles of the OVI emission lines that are needed to set upper limits on the amount of H_2 present in accretion columns andor outflows and to compare with models of line formation in accretion flows along magnetic flux tubes connecting the disk to polar magnetic starspots. Proposal ID: C068 Principal Investigator: Long, Knox S. Institution: Space Telescope Science Institute Proposal Title: Why do some Dwarf Novae Stand Still Z Cam systems are disk-dominated cataclysmic variables. Unlike normal dwarf novae, which burst and then return to quiescence in a few days to a few weeks, Z Cam systems exhibit extended high states lasting several weeks to several months following some otherwise normal outbursts. In standstill, the disk is in a high mass transfer state, but the flux at visible and UV wavelengths is intermediate between outburst maximum and quiescence. We propose to explore the physics of the standstill phenomenon with FUSE observations of a single Z Cam system, either Z Cam or EM Cyg, depending upon the behavior of the system during this FUSE Cycle. We will attempt a fundamental test of the hypothesis that the mass transfer rate from the secondary is higher in the fainter standstill state than in outburst by obtaining FUSE spectra at all orbital phases in standstill and in outburst. Access to the wavelength range below 200 A with a high resolution spectroscopic instrument is crucial to the success of such a test. In addition, we will model the FUSE spectra to measure (at least differentially) the structure of the disk and the wind in outburst and standstill, determining the effects of disk luminosity on wind mass-loss rate. Proposal ID: C070 Principal Investigator: OConnell, Robert Institution: University of Virginia Proposal Title: The Disk-Halo Connection in the Spiral Galaxy M101 We propose to use FUSE to study the spatial structure of the hot halo of the nearby spiral galaxy M101. This is a large, face-on, Sc galaxy with bright OB associations distributed across its face, making it an ideal candidate for such a study. We will search for O VI absorption from hot gas at five positions in M101 ranging in radii from 6 to 23 kpc. These observations will allow us to study the large scale structure of a disk galaxy O VI halo for the first time. Our results can be directly compared to O VI measures in the hot halo of the Milky Way. In addition, the nearly face-on orientation of M101 will allow us to search for hot gas escaping from its disk, as is predicted by all galactic fountain models. A direct detection of venting from the disk would provide crucial support to models of galactic fountains. We have used far-UV images from the AstroUltraviolet Imaging Telescope to select five of the brightest star-forming regionsOB associations in M101 as background targets. Proposal ID: C072 Principal Investigator: Ghavamian, Parviz Institution: Rutgers University Proposal Title: A Far Ultraviolet Observation of the DEM L 71 Blast Wave We propose a FUSE observation of a Balmer-dominated filament in the LMC supernova remnant DEM L 71. We will combine the O VI emission line widths and fluxes with optical Fabry-Perot and Chandra data to estimate the shock velocity, as well as the degree of electron-ion and ion-ion equilibration. This information will allow us to (1) construct evolutionary models of this supernova remnant, (2) study the physics of collisionless shock waves at intermediate (approx. 500 km per sec) speeds, and (3) complement FUSE data from a GTO observation targeting the X-ray bright, Fe-rich ejecta at the center of DEM L 71. Proposal ID: C073 Principal Investigator: Boisse, Patrick Institution: Ecole Normale SuperieureDEMIRM Proposal Title: Probing the very small scale structure (l approx. 50 AU) in the interstellar medium (continued) We propose to extend our study of the very small scale structure in the molecular, atomic and ionized phases of the interstellar medium initiated during cyle 1 and 2 to larger scales (l approx. 50 AU) by taking two additional spectra of the runaway O star HD 34078. HD 34078 (AE Aur) moves at a transverse velocity of 103 kms (or 20 AUyr); thus the 3 spectra obtained during cycle 1 allow us to sample adjacent lines of sight distant by approx. 10 and 15 AU at the cloud distance. These spectra are excellent (SN approx. 20 at 1100 A); strong HD lines are clearly detected as well as many lines from highly excited levels of H_2 (v 0, J 11 as well as v 1, 2, 3). A preliminary analysis indicates that i) prospects for detecting column density variations in H_2 J 0, 1, 2 (damped lines) are very encouraging (relative variations of 5 percent or better can be reached); ii) lines from the highly excited H_2 levels seem to vary in time and iii) the combination of the 3 observations provides, as expected, a very high quality spectrum. The two additional spectra planned for cycle 2 (oct 2001 and feb 2002) will probe separations of up to 30 AU. Our cycle 1 results provide a strong motivation for extending our search over larger scales by taking two other spectra during cycle 3. We will thus better characterize the column density fluctuations for a broad range of species, including H_2, HD, CO, CI, SiII, FeII etc and take advantage of the very high quality of the combined spectrum to perform a detailed modelling of the physical conditions in the foreground gas. Proposal ID: C076 Principal Investigator: Howk, J. Christopher Institution: The Johns Hopkins University Proposal Title: Constraining the Scale of Variations in the Hot Interstellar Medium We propose an experiment to measure the degree of variation in the Galactic hot ionized interstellar medium (ISM) over small angular 2.2 - 8.9 arcmin) and spatial (approx. < 2.6 - 10.3 pc) scales by observing OVI absorption towards four post-extreme horizontal branch post-EHB) stars in the globular cluster NGC 6752 (l,b) (336 deg, 26 deg); d 4.0 kpc; z -1.8 kpc. Our analysis of FUSE observations of OB stars in the Large Magellanic Cloud (LMC) has revealed approx. 30 percent- 180 percent variations in the OVI column density in the Galactic halo over the approx. 0.5 deg- 2.0 deg separations between these targets. This suggests the hot ISM is an extremely patchy medium. In principle such measurements can limit the size scale of individual absorbing regions and yield information on the relationship between the hot and cooler phases of the ISM. However, systematic difficulties in accurately determining the stellar continua for Population I OB stars limit the number of sight lines for which such measurements can be made. Our proposed observations will yield high signal-to-noise approx. > 20 per 0.05 A resolution element) spectra of these four hot, post-EHB stars in the metal-poor globular cluster NGC 6752. Because the stellar continua for these stars are very simple, we will be able to precisely measure the OVI column densities along these sight lines with (conservative) 1 sigma uncertainties of approx. < 10 percent. We will use the proposed observations to study variations of other phases of the ISM in these directions, including the cold neutral medium traced by H_2 if present) and the warm neutral medium (e.g., using ArI). The correlations (or lack thereof) in the total column density variations of these species will yield unique information on the relationships and interactions among the various phases of the ISM. Proposal ID: C078 Principal Investigator: Wood, Brian Institution: University of Colorado Proposal Title: Observing the Accretion Disk Around Miras Companion in the FUV We propose to obtain the first observations of the Mira wind accretion system in the far-UV below 1200 A. We will analyze C III and O VI emission lines formed in the accretion disk surrounding Miras companion star to better understand the physical properties of the accretion disk. These lines may also contain wind absorption features that can be used to study the wind of Mira B. Recent HSTSTIS observations revealed the presence of Lyman alpha fluoresced H_2 lines in the UV spectrum of Mira B, and we hope to detect additional H_2 lines in the FUSE bandpass to better understand the origin of this emission. Proposal ID: C079 Principal Investigator: Wood, Brian Institution: University of Colorado Proposal Title: The O I and N I Abundance in the Local Interstellar Cloud We propose to use FUSE to measure the O I and N I abundances in the Local Interstellar Cloud (LIC). We choose the white dwarf 40 Eri B as our target star because this is one of the few nearby stars that is hot enough to provide sufficient continuum emission to detect the LIC absorption against. Furthermore, H I and D I column densities for that line of sight have already been measured from HST observations of 40 Eri A, which show only LIC absorption. We will determine whether the OH and NH ratios in the LIC agree with previous measurements for much longer lines of sight. These measurements show no evidence for variation but they individually pass through many clouds and will therefore miss variability on smaller size scales. Knowledge of the OH and NH ratios and their variability within the LISM is important not only for understanding mixing processes in the ISM but also because of the possibility of deriving DH in the LISM by measuring DO andor DN and then multiplying by accepted OH andor NH ratios. This removes the need to measure H I at all, which is difficult in many cases. Proposal ID: C080 Principal Investigator: Kirshner, Robert P. Institution: Harvard University Proposal Title: Far-Ultraviolet Spectra of a Supernova to be Named Later We propose observing a newly-discovered supernova with FUSE as a target of opportunity. Our experience with HST and IUE ultraviolet spectra shows how informative they can be. With FUSE, we can explore a previously unobserved part of the spectrum where many important lines will help in building a complete picture, especially of circumstellar interactions. The resolution of FUSE is excellent for this purpose because it neatly separates circumstellar features from interstellar lines and the ability to move promptly to a good target is a very large advantage over HST. A recent example of a type II, SN1998S, illustrates what a STIS spectrum can (and cannot) do, and gives us a solid basis for predicting what is required for measurements with FUSE. We hope to continue our HST Target-of-Opportunity program, and we would aim to combine our FUSE observations both with our ground-based data and with STIS data. The probability of having one suitable target per year is high. Proposal ID: C081 Principal Investigator: Shull, Michael Institution: University of Colorado, Boulder Proposal Title: Weighing the Low-Redshift Lyman alpha Forest Both theory and modeling suggest that a substantial fraction of low-redshift baryons reside in the intergalactic medium, associated with warm photoionized Lyman alpha absorbers. We propose FUSE studies to make quantitative measurements of the baryon content of a class of saturated Lyman alpha absorbers, with N_HI > 10^(13.5) cm^(-2), which probably dominate the baryon mass. The Colorado IGM group just completed a Hubble GHRSSTIS survey of 201 Lyman alpha absorbers along 31 sightlines. In our STIS and earlier FOS surveys, we identified 3 promising sightlines (HE 1029-1401, MRC 2251-178, Ton 28) with 10 strong Lyman alpha absorbers, for FUSE studies of Lyman betaLyman gamma absorption. These 10 new systems would greatly increase the current FUSE database (13 systems) of strong low-z absorbers. FUSE observations of the higher Lyman lines will provide reliable measurements of their H I column density and doppler parameter, critical for precise measures of the baryon content and for accurate determinations (or limits) of their metallicity. The observation of HE 1029-1401 allows us a chance to test the primordial nature of a Lyman alpha absorber in a cosmic void through its metallicity. All sightlines also probe Galactic high velocity clouds and the Magellanic Stream. Proposal ID: C082 Principal Investigator: Lauroesch, James Institution: Northwestern University Proposal Title: The Abundance of Interstellar Fluorine We propose to obtain high signal-to-noise ratio FUSE observations of the interstellar F I 954 A absorption toward a sample of three stars HD 103779, HD 164816, and HD 190918). The nucleosynthetic source(s) of fluorine are still a matter of debate -- the present day abundance of fluorine can potentially constrain models for pulsationally driven dredge-up in asymptotic giant branch stars. An accurate measure for the depletion behavior of fluorine will determine whether it may be detectable in QSO absorption line systems -- an unambiguous detection of fluorine at suitably high redshifts would provide the best evidence to date for the neutrino process in massive stars. Furthermore, due to its extreme reactivity, measurement of the gas-phase interstellar fluorine abundance is important for models of grain chemistry. Despite the importance of measuring the interstellar fluorine abundance, only one previous detection has been made due to the low relative abundance of fluorine, the lack of lines outside the far-UV, and the blending of the available F I transitions with lines of H_2. Examination of the far-UV spectra of the three stars in our sample shows they have relatively high far-UV fluxes at 954 A, as well as apparently no blending between H_2 absorption and the expected location of the strongest F I line. These stars all have N(H) > 1.4x10^(21), yielding an expected F I equivalent width of > 10 mA (assuming the one depletion measurement is correct). Proposal ID: C083 Principal Investigator: Gaetz, TerranceJ. Institution: Harvard-Smithsonian Center for Astrophysics Proposal Title: Probing the Reverse Shock in an Oxygen-Rich Supernova Remnant We will use FUSE to examine locations around the X-ray bright ring seen in the high resolution Chandra X-ray observations of the oxygen-rich supernova remnant 1E0102.2-7219. Our three FUSE MDRS pointings will sample regions with differing distributions of OIIIf emission and X-ray emission (largely OVII and OVIII). An additional off-target pointing will assess the continuum scattered from stars in the nearby HII region, allowing for a more reliable background subtraction. The resulting detailed information about the distribution and kinematics of OVI relative to the other components will show whether the OVI contribution is associated more with the X-ray ring (an ionizing reverse shock) or with the OIIIf filamentation radiative shocks driven into denser ejecta). Lastly, an enumeration of the mass contributions from the various ionization stages will allow a more reliable determination of the mass of oxygen in the remnant. Proposal ID: C084 Principal Investigator: Stocke, John T. Institution: University of Colorado, Boulder Proposal Title: O VI Absorbers in Spiral Dominated Groups of Galaxies We propose to investigate whether nearby spiral-rich galaxy groups are a significant reservoir of gas in the so-called warm-hot phase; i.e., collisionally-ionized gas at T approx. 10^(5-7) K. Numerical simulations of intergalactic gas predict that this warm-hot phase gas could account for 40-60 percent of all baryons locally. The most viable detection method for such gas, O VI absorption in HSTFUSE spectra, implies a baryon fraction of only approx. 10 percent. Where might these warm-hot baryons be hiding One possibility is in spiral-rich groups of galaxies. These are very numerous, marginally bound, and have been predicted to have intragroup media at the right temperature to be O VI absorbers. Spiral rich groups also occupy a fractional volume small enough that they have not been probed extensively by current FUSEHST observations. Therefore, we propose FUSE observations of three nearby groups of galaxies probed by bright AGN sightlines to search for O VI absorbers. For one sightline the intragroup medium has already been detected in Lyman alpha with HST. Proposal ID: C086 Principal Investigator: Kraemer, Steven B. Institution: Catholic University of America Proposal Title: FUSE Observations of the Dwarf Seyfert Nucleus of NGC 4395 The Sd IV dwarf galaxy NGC 4395 is the nearest (d approx. 2.6 Mpc) and least luminous (L_bol < 10^(41) ergs s^(-1)) example of a Seyfert 1 galaxy. This unique object possesses all of the classic Seyfert 1 properties in miniature, including broad and narrow emission lines, a non-stellar continuum, and highly variable X-ray emission, presumably powered by a small (10^(5) M_sun) black hole. Furthermore, there is evidence for blue-shifted, intrinsic absorption lines in the UV (C IV lambda lambda 1548.2, 1550.8), while X-ray spectra show the presence of bound-free edges from O VII and O VIII and evidence for even more highly ionized gas. The UV absorption could arise within the X-ray absorbers or, alternatively, within the emission-line gas, which we have determined to have a high covering factor. The unique capabilities of FUSE provide the means with which to constrain the ionization state, column density, and covering factor of the absorbers and, hence, distinguish between these two possibilities. By extending our investigation of intrinsic absorption to the low luminosity extreme of the Seyfert population, we will obtain crucial insight into the effects of luminosity, global covering factor, and central black hole mass on the intrinsic absorbers. A second goal of this project is to constrain the spectral energy distribution of the non-stellar continuum radiation, which may be unique in this object as a consequence of its small black hole mass. Proposal ID: C088 Principal Investigator: Lecavelier, Alain Institution: Institut dAstrophysique de Paris, CNRS Proposal Title: A search for the 10^5--10^6 K gas in clusters of galaxies with massive cooling flow The persistent non-detection of the products of cooling flows in cluster cores at non-X-ray wavelenghts continues to be a major enigma. Recently, FUSE is reported to have been successfully used to detect the O VI doublet at 1032, 1038 A, from a cooling flow elliptical galaxy. This has provided a direct evidence for approx. 3x10^5 K ISM in this galaxy, in a quantity which is consistent with the cooling flow rate of approx. 0.4 M_sun yr^(-1) derived earlier from ROSAT observations. To search for the much needed similar evidence for massive cooling flows associated with rich clusters of galaxies, we propose here FUSE observations of five clusters whose abnormally large cooling flow rates (typically 400 M_sun yr^(-1), combined with low Galactic H I column densities in their directions and their relatively small distances make them promising targets. In order to develop a comprehensive understanding of these systems, a parallel programme of sensitive, aperture-synthesis imaging of these clusters at metre wavelengths is being undertaken, to search for aged population of relativistic electrons. Proposal ID: C090 Principal Investigator: Kriss, Gerard A. Institution: Space Telescope Science Institute Proposal Title: Simultaneous FUSE, HST, and Chandra Observations of Intrinsic Absorbers in NGC 7469 and Mrk 279 Photoionized, warm absorbing gas is an important component of the nuclear structure of AGN. About half of all low-z AGN show X-ray warm absorbers and high-ionization UV absorption lines, but the relationship of the X-ray absorber to the UV-absorbing gas is not clear. Only a handful of high-spectral-resolution observations with FUSE, HST, and Chandra currently exist (NGC4151, NGC3516, NGC3783, NGC5548, Mrk509). These show a diversity of kinematic structure and ionization states in the absorbers. Fewer still of these have simultaneous observations that avoid the uncertainties introduced by variability (NGC4151, NGC3783). We propose to increase significantly the sample of low-redshift AGN studied at high spectral resolution in the X-ray and the UV by obtaining simultaneous FUSE, HST, and Chandra spectra of NGC7469 and Mrk279. Both are bright AGN with O VI absorption resolved in recent FUSE observations. The new simultaneous observations will resolve the kinematics and ionization state of both the UV and X-ray absorbers. This will permit a definitive assessment of their relationship and give clues to their location in the nuclear region. Proposal ID: C092 Principal Investigator: Crenshaw, D. Michael Institution: Catholic University of America Proposal Title: Simultaneous FUSE, HST, and Chandra Observations of the Seyfert Galaxies NGC 4151 and NGC 5548 We will obtain simultaneous FUSE, HSTSTIS echelle, and Chandra HETGMEG spectra of the Seyfert 1 galaxies NGC 4151 and NGC 5548, to determine the physical conditions and abundances in their intrinsic UV and X-ray absorbers and place constraints on the unobservable EUV continuum radiation. These observations are crucial for determining the structure and dynamics of the mass outflow in active galaxies and obtaining clues to its origin. NGC 4151 has an unusually high column of ionized gas, which may be related to our viewing angle relative to the the accretion disk and ionization bicone. The simultaneous observations of NGC 4151 are aimed at determining the physical conditions in the high-column X-ray absorber, which are currently unknown, and its connection to the UV absorbers. NGC 5548 has a more typical column of ionized gas, but efforts to understand the connection between its UV and X-ray absorbers have yielded conflicting results, due to variability and non-simultaneous observations. FUSE provides the missing link between the UV and X-ray absorbers, because gives us the final pieces of information needed to fully determine their ionization states, column densities, abundances, covering factors, and kinematics. Proposal ID: C094 Principal Investigator: Szentgyorgyi, Andrew Institution: CfA Proposal Title: A FUSE Study of the Planetary Nebula NGC 246 New Ne V lambda 3426 images of NGC 246 show a bright structure surrounding a faint central region which is likely to be a hot bubble blown out by the luminous central star. FUSE measurements of Ne V lambda 1146 emission from the nebula are needed to establish the presence of the shock expected from the energetics of the fast stellar wind. FUSE O VI doublet measurements will determine to what extent swept-out material in the nebula reflects the Wolf-Rayet abundances of the central star. We propose to observe spectra at two positions across the conduction front of the bubble. Proposal ID: C095 Principal Investigator: Ganguly, Rajib Institution: The Pennsylvania State University Proposal Title: Monitoring the Intrinsic Absorption Complex Toward RX J1230.8+0115 We propose to monitor the intrinsic O VI absorption complex toward RX J1230.8+0115. The complex consists of six absorbing structures spread out over 5000 km per sec. An existing STIS-E140M spectrum also shows these structures in Lyman alpha, N V, and C IV. Together with further STIS-E140M observations to be proposed in HST Cycle 11, we will measure changes in the equivalent widths of spectral profiles with time. In addition, we will measure the coverage fractions and column densities over a wide range of ionization species to not only decipher the underlying cause of variability, but also the physical conditions e.g., ionization parameter, density, metallicity) of the gas through detailed photoionization modelling. The two causes of time variability, bulk motion and ionization state changes of the absorbing gas, show markedly different signatures in the way high and low ionization lines vary. The photoionization modelling will provide sizes which, when combined with the coverage fractions, will yield the geometry of the absorbing structures. These observations, the first for a complex of possibly intrinsic narrow absorption lines at low redshift, will test the hypothesis that the absorbers form as instabilities in the outflowing, relativistic wind. Proposal ID: C096 Principal Investigator: Finley, David S. Institution: Eureka Scientific, Inc. Proposal Title: The Influence of Weak Winds on DAO Abundances This proposal seeks build on the existing FUSE observing programs related to DAO stars by including three additional targets that should significantly enhance the utility of the data set for measuring abundance variations with temperature and gravity. In turn, those abundance measurements will be applied to ascertaining whether weak winds determine abundances in DAO, and how those winds vary with the stellar parameters. Proposal ID: C097 Principal Investigator: Dufour, Reginald J. Institution: Rice University Proposal Title: The Wolf-Rayet Star HD 192163 And Its Surroundings HD 192163 is the Wolf-Rayet star associated with the emission nebula NGC6888, the brightest of the WR shell nebulae. The wind of the star has swept the circumstellar material, lost during the stars previous red supergiant phase, into a dense shell. The shell has fractured, and the internal pressure of the bubble is now driving a 100 km s^(-1) shock into material external to the shell. We propose to observe the Wolf-Rayet star with FUSE to examine the abundances in this external material. In particular we are interested in the carbon abundance, which we will derive from absorption in lines of C III and C II. Because the material is from the same source as the nitrogen-rich shell, we also expect considerable N III and N II absorption. The proposed observation will also acquire the far UV spectrum of HD192163, which can be used to constrain stellar atmosphere models for the central star. Proposal ID: C101 Principal Investigator: Guerrero, Martin Institution: University of Illinois Proposal Title: O,VI Emission from the Cats Eye Nebula Chandra observations of the planetary nebula (PN) NGC 6543, the Cats Eye Nebula, have unambiguously resolved diffuse X-ray emission resulting from the interaction of its fast stellar wind with the cool nebular shell. The physical conditions of the shocked stellar wind in NGC 6543 should reflect the effects of heat conduction and mass evaporation at the interface with the nebular shell. The observations show that the shocked wind has been cooled, but the abundances do not show evidence for mass evaporation from the nebular shell. We propose to use FUSE to directly observe the nebular O VI emission lines, the dominant cooling lines from the gas at 3 x10^5 K in the interface region. These observations will allow us to probe the location, content, and physical conditions of the gas at the interface, thus providing insight to the processes that control the physical conditions of the hot gas and drive the evolution of PNe. Proposal ID: C102 Principal Investigator: Guinan, Edward F. Institution: Villanova University Proposal Title: FUSE Observations of the Sun in Time - Transition Region Physics and Evolution of FUV Irradiances We propose to use FUSE to complete an in-depth study of the evolution of the transition region and low corona of a solar-mass star throughout its main-sequence lifetime. This program is part of a comprehensive study of the Sun in Time across the electromagnetic spectrum. We have defined a homogeneous sample of single G0-5 V stars with well-known rotation periods that are proxies of the Sun at different ages. So far we have observed three targets and have time approved in Cycle 2 for a fourth star. We are studying the dynamics and energetics of the lower layers of the atmospheres of these solar-like stars, and investigating the variations of the properties with age and rotation period. Emission measure and temperature analysis will allow us to obtain a complete 3-D atmospheric model of active regions that we will link to the previously obtained coronal X-ray data. Transition region electron densities are inferred through the well-established density-sensitive ratio of the C III 1176 A 977 A lines. This important diagnostic will be used to identify and model the relevant magnetic structures based on the solar analogy, and, together with our coronal X-ray (ROSAT, ASCA, XMM, Chandra), EUV (EUVE), and TR (IUEHST) data, to infer the importance of coronal energy releases. Our FUSE investigation is central to the understanding of the evolution of magneto-dynamic atmospheric phenomena, and the associated high-energy emissions in the Sun and in solar-type stars. It also bears on the crucial question of the influence of the young Suns strong FUV emissions on the developing planetary system - in particular on the photochemical and photoionization evolution (and possible erosion) of early planetary atmospheres and ionospheres. To this end, we are constructing spectral irradiance tables for the Sun at different ages for which the proposed FUSE observations fill a vital spectral and energy gap. Proposal ID: C103 Principal Investigator: Guinan, Edward F. Institution: Villanova University Proposal Title: Eclipsing Binaries in the Large Magellanic Cloud Accurate Distances and Physical Properties The distance to the LMC is crucial to calibrating the cosmic distance scale but remains controversial and uncertain despite the efforts of many investigators. We have demonstrated that the analysis of eclipsing binaries (EBs) has the potential to resolve this controversy. Guinan et al. (1998) and Fitzpatrick et al. (2001) analyzed ground- and space-based observations of HV 2274 and HV 982 and determined LMC distance moduli of (V-M_v)_(circ) 18.30 plus minus 0.07 mag and (V-M_v)_(circ) 18.31 plus minus 0.10 mag, respectively. Such an excellent agreement demonstrates the potential of this method, and the suitability of EBs as accurate standard candles. However, these are only results for two stars and the method must be verified with additional observations and extended wavelength coverage into the Far-UV where the stars strongly radiate. The primary goals of the FUSE observations are to secure accurate, definitive temperatures and interstellar extinctions to the target stars Sp. Typ. O7-B2), whose energy maxima occurs in the FUSE spectral range. Four of the proposed targets have FOSSTIS spectrophotometry covering 1150-8000 A and observations are planned for the remaining two. The FUSE observations will be combined with UVoptical spectrophotometry and with light and radial velocity curves that will yield the masses, radii, T_eff, E(B-V), log g, and FeH of the stars. The distances to the stars (and the LMC) are directly determined from their radii, temperatures and apparent brightnesses flux received at Earth corrected for ISM extinction). When the FUSE observations of all of our program stars are available, and when combined with our other datasets, the uncertainty of the LMC distance will be reduced to better than 2-3 percent. Proposal ID: C105 Principal Investigator: Bonamente, Massimiliano Institution: University of Alabama in Huntsville Proposal Title: FUSE observations of warm gas in clusters of galaxies and of Galactic OVI emission Many clusters of galaxies show substantial extreme-UV and soft X-ray emission in excess of that expected from the hot intracluster medium ICM). The excess component can be explained by the presence of a substantial warm component (T 10^(5.5) - 10^6 K) of the ICM. This gas reveals itself through absorption lines in the spectra of background QSOs. The FUSE passband is ideally tuned for the detection of the O VI resonant doublet (lambda lambda 1032, 1038 in the rest frame) by clusters at low redshift. We propose FUSE observations of three QSOs in the background of the Coma, A2244, and A1267 clusters respectively, to test for the presence of such warm gas. Additionally we will also be able to use these observations to study hot gas in our own galaxy. Recent FUSE observations reveal the presence of Galactic O VI emission towards the Coma and Virgo clusters. The proposed observations will further those studies towards a deeper understanding of the gas responsible for the emission. Proposal ID: C106 Principal Investigator: Ayres, Thomas R. Institution: University of Colorado Proposal Title: Glimmers of Life in the Coronal Graveyard Red giants represent the final stage in the life cycle of normal stars. Those evolving from low-mass dwarfs like the Sun were magnetically active for most of their main sequence phase, thanks to a spin-catalyzed convective dynamo. At the same time, such stars also experienced significant rotational braking by their coronal winds. Once they expanded into red giants, their spins further plummeted, and they should have become magnetically dead; an expectation seemingly confirmed by a conspicuous lack of coronal X-ray detections. However, reports of the deaths of red giant coronae were premature - far-UV C IV emissions (an important coronal proxy) have been detected in archetype members of the class by HST, and now O VI has been seen by FUSE in at least one case. Curiously, however, features formed at similar temperatures -- Si IV and N V -- are absent, apparently removed by a mysterious cool absorber. Our objective is to obtain additional detections of the O VI doublet in key red giants, to help address the question of the nature of the cool absorber, and the implications for smothering any coronal X-ray emission. If we can show that there is lingering magnetic activity on the red giants, we might have found a possible link to the acceleration of their chromospheric winds, which chemically enrich the ISM and themselves are a long-standing astrophysical puzzle. Proposal ID: C107 Principal Investigator: Ayres, Thomas R. Institution: University of Colorado Proposal Title: Coronal Iron Survey The Yellow Giants We propose a small survey of yellow giants to study the Fe XVIII lambda 974 coronal forbidden line, discovered recently in several late-type stars by FUSE. We selected candidate targets from an extensive HST STIS survey of the analogous Fe XXI lambda 1354 feature. Active yellow giant stars (G0--G9 III) are the best choice, because their coronal emission measures narrowly peak at approx. 6x10^6 K, where Fe L-shell species -- such as Fe XVIII -- are most prominent. Measurements of Doppler widths and shifts of the lambda 974 feature, at the high velocity resolution afforded by FUSE, will revolutionize the study of stellar coronal dynamics in ways that the current generation of orbiting X-ray observatories cannot. A novel aspect of our program is use of the interstellar absorption feature in the adjacent bright C III lambda 977 emission core to calibrate the velocity scale. Proposal ID: C109 Principal Investigator: Bowen, David V. Institution: Princeton University Proposal Title: A search for OVI absorption in the halo of the Large Magellanic Cloud We propose searching for O VI absorption in the extended halo of the Large Magellanic Cloud (LMC) by observing the background AGN NGC 1672 (z 0.0045). The AGN lies 11.24 degrees from the center of the LMC, which corresponds to 9.7 kpc; this is 1.9 times the optical radius of the galaxy and just beyond the last determined H I measured from 21 cm emission lines, corresponding to a column density of N(H I)1x10^(19) cm^(-2). Our science goals include determining whether a) the LMC is surrounded by a hot halo capable of causing O VI absorption at a radius of 10 kpc; b) the strength of the absorption is similar to that in the Galaxy, in the central regions of the LMC, or to high-redshift O VI systems; c) the O VI shows multicomponent structure caused by the two thin H I disks separated by 60 kms which comprise the galaxy; d) there are any other O VI lines at velocities different from the LMC or the Milky Way, which might be from Local Group intragroup gas. We have also determined that two other fainter AGN lie only a few kpc on the plane of the sky from NGC 1672. Probing the LMC halo on these scales would be invaluable for deriving the covering factor of the gas and small-scale variability in its physical condition. We seek 7 ksec exposures per object to establish if there is sufficient far-UV flux for future FUSE observations. Proposal ID: C110 Principal Investigator: Sion, Edward Institution: Villanova University Proposal Title: Probing White Dwarf Accretors and Inner Disk Structure of High Accretion Rate Dwarf Novae The disk instability model predicts that the accretion rate of a dwarf nova should be vanishingly small during quiescence. However, the far UV spectra of many high accretion rate dwarf novae above the period gap have steeply rising FUV continua which require accretion rates at, or uncomfortably close, to the critical accretion limits such that dwarf nova outbursts would not be expected to occur by the disk instability mechanism. RU Peg contains what appears to be the hottest white dwarf yet found in a dwarf nova with T_eff 53,000K while SS Aur contains a 30,000K white dwarf and a Hubble FGS parallax indicating that the radius of the FUV emitting source is that of a white dwarf. There is also a second unidentified hot component in some dwarf novae which should show up in the FUSE range. Our proposed FUSE spectra will quantitatively answer what the correct fractional flux contributions of the accretion disk, white dwarf and other hot component(s) are to the FUV during quiescence, thus testing theoretical predictions of the disk instability model as well as yielding critical white dwarf surface temperatures, rotation rates, and chemical abundances. Proposal ID: C111 Principal Investigator: Dupree, Andrea K. Institution: Smithsonian Astrophysical Observatory Proposal Title: An Evolving Trio of Hybrid Stars Hybrid stars form the critical link in the evolution of cool stars connecting solar-corona-like objects with cool luminous stars, and documenting the evolution of magnetic structures. Three hybrid targets for FUSE can clearly illustrate atmospheric evolution for approx. 2 M_sun stars - gamma Dra (HD 164058), iota Aur (HD 31398), and mu UMa (HD 89758). FUSE spectra can identify atmospheric extent (through fluorescent Fe II lines), energetics (with O VI emission and density diagnostics), and dynamics (through C III and O VI profiles) in this well-chosen sequence of 3 hybrid objects of similar mass yet different evolutionary stage. FUSE spectra can define characteristics of these evolving atmospheres, determine the temperature and velocity profile of the wind, and provide observational benchmarks for theoretical models. Proposal ID: C113 Principal Investigator: Bianchi, Luciana Institution: The Johns Hopkins University Proposal Title: The Youngest, Massive Star Clusters in M33 Young massive clusters, which appear to be abundantly forming in merging galaxies, but are not found in the Milky Way, provide the opportunity to study the conditions necessary for the formation of massive, compact stellar systems. This insight into conditions present during the earliest epochs of galaxy formation, when ancient globular clusters (GC) are believed to have formed, helps constrain scenarios of galaxy formation and evolution. We propose to observe three extremely young, UV-luminous star clusters in the Local Group spiral galaxy M33. These young, massive, and compact objects provide a key link to the young cluster systems in mergers, where our insight is currently limited, and these may be the only such counterparts which are accessible to the FUSE sensitivity. The objects are selected from our previous extensive survey of M33 with HST WFPC2 imaging in 4 bands - U, B, V and far-UV (1700 A). From multiband integrated photometry we determined age upper limits of a few million years for our target objects, by comparison with synthetic single-age population evolutionary models. Spectra in the FUSE range will provide precise ages for these objects, and unambiguously reveal their properties, by comparison with synthetic model spectra of extremely young single-stellar populations, and by the analysis of the strong spectral signatures that will reveal the massive star content. The wind momentum and UV radiation flux from the massive stars will be compared with gravitational properties of each cluster (from mass estimates and light profiles), to assess whether such systems can survive internal dynamical evolution. Proposal ID: C114 Principal Investigator: Brown, Alexander Institution: University of Colorado Proposal Title: Coronal Dynamics and Complete Flare Energy Budget for the M Dwarf AD Leo We propose FUSE (50 ksec) observations of the dMe flare star AD Leo coordinated with Chandra-HETGS (110 ksec requested AO3) X-ray spectroscopy to accurately measure for the first time the complete energy budget for coronal flares. FUSE observations of the Fe XVIII 975 A coronal forbidden line are absolutely vital for determining the dynamical energy losses of the flares. Changes in the C III and O VI resonance lines, formed in the transition region between 50,000 and 250,000 K, will also be recorded by FUSE. Chandra HETGS spectra will be used to measure the temporal changes in the coronal emission measure, temperature, density, and elemental abundances, but are unlikely to be able to measure flare dynamics. AD Leo is one of the brightest dMe stars in the FUV and X-ray regions and flaring rate data suggests that we should see about 10 moderate (factor of a few) and one large (factor of 10-20 enhancement) flares in a 30 hour observation. We are submitting two very similar flare proposals, one for a single dMe flare star and the other for an active binary - our goal is to examine coronal dynamics for both situations and see how different they are. Proposal ID: C116 Principal Investigator: Holberg, Jay B. Institution: University of Arizona Proposal Title: A FUSE Determination of the Gravitational Redshift and Spectroscopic Mass of Sirius B We propose FUSE observations of the massive white dwarf Sirius B to measure its gravitational redshift and determine its surface gravity. From these measurements we will obtain an accurate spectroscopic mass which can be directly compared to an improved astrometric mass for this key white dwarf. A second goal of these observations is to independently measure the photometric radius of Sirius B in the FUV. All of these measurements will permit testing of the theoretical mass-radius relations for degenerate stars to an unprecedented level of accuracy, approaching 1 percent. A secondary science objective we will pursue with these data is a determination of the interstellar DH ratio for the Sirius line of sight. We also propose FUSE observations of HD 74389B the only other known white dwarf, in addition to Sirius B, in a resolved binary system containing an A star. Proposal ID: C118 Principal Investigator: Fitzpatrick, Edward L. Institution: Villanova University Proposal Title: The Atmospheres of High-Latitude Early B Stars We request observing time with FUSE to obtain far-UV spectra of 11 lightly reddened, mid-to-early B-type main sequence stars (BVs) located in the galactic halo. These data, combined with complementary data from a Cycle 2 program, will be part of a comprehensive investigation of the ability of current model atmosphere calculations to reproduce the observed properties of the BVs, including the overall energy distributions and the detailed absorption line spectra. This study will provide a benchmark and a reality check for studies of more exotic early-type objects, since the BVs are the hottest and most luminous stars whose atmospheres can be modeled with simplifying assumptions, such as LTE, plane-parallel geometry, and hydrostatic equilibrium. Halo targets are chosen because the early-B stars in the galactic disk are either too bright to be observed by FUSE or too compromised by interstellar absorption to allow the stellar properties to be examined in detail. This program --- which is essentially a survey of the best-observed halo BV stars --- will also allow us to address the issue of the normalcy and origin of these stars, and will provide a set of unreddened standard stars for extinction studies with FUSE data. Proposal ID: C123 Principal Investigator: Reimers, Dieter Institution: Universitat Hamburg Proposal Title: Intergalactic Ionized Helium Absorption toward the UV-brightest high-z Quasar HS 1140+2711 We propose to study intergalactic HeII absorption over the redshift range 2.29 < z < 2.63 toward the QSO HS 1140+2711 from the Hamburg Bright Quasar Survey. HS1140+2711 was discovered in a FUSE Cycle 1 snapshot program, specifically designed to find additional extremely UV-bright QSOs for that purpose. With F_lambda approx. (3-5) times 10^(-15) erg s^(-1) cm^(-2) A^(-1) in the He II 304 A, forest, this target is nearly a factor of 2 brighter than HE 2347-4342. Therefore, promises to dramatically increase the quality of information on the helium reionization epoch and on the ionizing sources of the IGM. With these new data, we will be able to observe the recovery in HeII opacity following the helium reionization epoch at z < 3. We will also measure the cosmic variance of mean He II opacity and use its fluctuations to understand the spatial density of ionization sources. With the high SN FUSE data, and combined with high-SN UVESVLT optical data, we expect to identify a major fraction of the He II Ly alpha lines with their H I Ly alpha counterparts. We will also be able to diagnose the nature of the ionizing sources from the optical-depth ratios, tau_HeII divided by tau_HI. Proposal ID: C125 Principal Investigator: Henry, Richard C. Institution: The Johns Hopkins University Proposal Title: Scattering From Interstellar Dust Near Stars We propose to make the first observations of dust halos around stars in the UV. Such observations can only be done with instruments such as FUSE which have a high sensitivity and a small field of view. Through these observations, we will unambiguously determine the optical constants of the interstellar dust grains. If the dust grains are highly forward scattering, the emission around the star will be strongly peaked near the star while if the grains scatter isotropically the emission will be more uniform. We have chosen a set of targets near two stars - alpha Cru and epsilon CMa. The first is a known source of intense diffuse UV emission, presenting an ideal test case for these observations, while the latter is a control star with a well-studied line of sight allowing us to test off-axis instrumental scatter in the FUSE spectrograph. Proposal ID: C126 Principal Investigator: Grady, Carol Institution: Eureka Scientific Proposal Title: Tracing the Molecular Environments of Herbig Ae Stars with FUSE Spectroscopic observations of Herbig AeBe stars have revealed a wide range of stellar spectral energy distributions, solid state features in the IR, and a wealth of wind and infall signatures in the optical and UV. Combining these data with high spatial resolution, high dynamic range coronagraphic imagery suggests that distinctive features in the IR spectra may originate not in the disk but in an extended envelope which is expected to account for the IR photodissociation region features. The available UVFUV spectral data for some of the hotter Herbig Ae stars indicate that the envelope systems have enhanced neutral atomic and molecular gas in the line of sight compared to the disk-only systems. For cooler Herbig Ae stars, fluorescent H_2 emission should be enhanced in the envelope systems compared to the disk systems, and the line of sight H_2 can be probed using the lines overlying the O VI emission. We propose testing this hypothesis with FUSE LWRS spectra of three Herbig Ae stars, with two stars chosen on the basis of their IR spectral features indicating the presence of envelopes, and one single star with a disk which shows no envelope features in the STIS coronagraphic imagery. Proposal ID: C127 Principal Investigator: McCandliss, Stephan R. Institution: The Johns Hopkins University Proposal Title: Searching for Far-UV Fluorescence of Molecular Hydrogen in NGC 2023 We propose to acquire a comprehensive set of FUSE observations of the reflection nebula NGC 2023. These data will allow us to form a complete picture of the far-UV pumping and subsequent fluorescent cascade within a dusty and UV intense environment where the formation of molecular hydrogen on grains and the strong radiation field may be influencing the ground state population distribution. This study will be aided by existing low resolution longslit sounding rocket observations of the nebula and central star, from which we have derived a far-UV dust scattering model and which have provided intriguing hints of emission above the scattered light. We will use infrared observations of the molecular hydrogen quadrupole emissions in NGC 2023 to guide our selection of pointings to uncover the far-UV fluorescent cascade within this reflection nebula. The high spectral resolution of FUSE will allow us to easily distinguish the fluorescent emission from the nebular scattered light. The results will provide useful constraints on models of photo-dissociation regions. Proposal ID: C128 Principal Investigator: Brown, Thomas M. Institution: GSFC Proposal Title: How Does Abundance Affect the Strength of UV Emission in Elliptical Galaxies The hot stars responsible for the UV upturn phenomenon are key indicators of age and abundance for the stellar populations in ellipticals. These stars are well-isolated in the FUSE wavelength range from the cooler main sequence stars that complicate interpretation at wavelengths longer than 2000 Angstroms. The strength of the UV upturn correlates well with optical metallicity indices, but these optical indices trace abundances in the cool population, not the hot stars that produce the UV emission, so the relation between abundance and UV upturn remains unclear. We are currently obtaining FUSE observations of two giant elliptical galaxies with strong UV emission NGC 4649 and NGC 1399. For the next cycle, we propose complementary observations of two ellipticals with weak emission NGC 221 and NGC 4472. Although NGC 221 is a fundamental testing ground for theories of stellar and galactic evolution, its spectrum has never been measured below Lyman alpha. The galaxy is unique because it the closest and most metal-poor elliptical, with the weakest measured UV upturn. NGC 4472 was observed by the Hopkins Ultraviolet Telescope, but at considerably lower signal-to-noise and resolution than possible with FUSE. With FUSE data, the absorption lines of C, N, and Si prevalent in the far-UV will provide invaluable composition diagnostics for the hot stellar populations in ellipticals. Furthermore, FUSE is uniquely qualified to measure the Lyman series, an important diagnostic of effective temperature and surface gravity. FUSE presents the opportunity to understand the role of abundance in the UV upturn phenomenon. Proposal ID: C129 Principal Investigator: Brown, Thomas M. Institution: GSFC Proposal Title: The Formation Mechanism of Helium-Rich Subdwarf B Stars Subdwarf B stars in the Galactic field are the metal-rich counterparts to the extreme horizontal branch stars found in globular clusters, and they are the dominant source of UV emission in old elliptical galaxies. They are distinguished by their high effective temperature T_eff > 25,000 K) and surface gravity (log g > 5). The sdB stars all show significant abundance anomalies most are extremely deficient in helium and heavy elements, but a minority are helium-rich. Deficiencies in helium and heavy elements have been attributed to gravitational settling, but the helium-enriched members of the class present a puzzling exception, because radiative levitation should be too weak to prevent gravitational settling. We hypothesize that these helium-rich sdB stars are the result of a delayed helium-core flash on the white dwarf cooling curve. The convective zone produced by this flash will penetrate the hydrogen envelope, mixing hydrogen into the hot helium-burning interior, where is rapidly consumed. The resulting star should show greatly enhanced helium and carbon with respect to the other heavy elements. This phenomenon is analogous to the born again scenario for producing hydrogen-deficient R CrB stars following a very late helium-shell flash. To test this hypothesis, we propose FUSE observations of three helium-rich sdB stars. FUSE observations will provide the first far-UV spectra of this unusual class of stars. Proposal ID: C131 Principal Investigator: Hoopes, Charles Institution: Johns Hopkins University Proposal Title: Probing the Coronal Gas in Starburst Superwinds Through O VI Emission Galactic scale superwinds from starbursts have an important impact on the evolution of galaxies and the intergalactic medium. However, the full extent of their influence is still in question, due to the lack of information on the coronal phase in the wind. Emission from this 10^5 - 10^6 K gas may dominate the cooling in the superwind, and thereby determine the evolution of the wind and its ability to deposit mass and energy into the intergalactic medium. We propose to observe O VI lambda lambda 1032, 1038 emission from the coronal gas in two prototypical starburst superwind galaxies M82 and NGC 253. With these observations we will determine the cooling rate of the coronal gas, and compare it with the energy input from supernovae. This will allow us to determine whether cooling strongly affects the dynamical evolution of these winds. We will also investigate the kinematics of the gas in the wind, and compare this to the kinematics of cooler gas seen in the C III lambda 977 emission line. In conjunction with FUSE O VI absorption measurements of other starbursts in cycles 1 and 2, Chandra X-ray images, and optical emission line data, these observations will provide a greater understanding of the evolution of starburst superwinds. Proposal ID: C132 Principal Investigator: Bouret, Jean-Claude Institution: LAS de Marseille Proposal Title: Probing Hot and Cold gas in Beta Pictoris Circumstellar Environment The wide circumstellar disk of dust and gas of Beta Pictoris is one of the most fascinating and well studied object of todays astronomy. Recent osbervations by ISO (Thi et al. 2001) and by FUSE (Lecaveliers des Etangs et al. 2001; Deleuil et al. 2001) still have brought new surprises. FUSE observations of Beta Pictoris have indeed revealed the very first emission lines in the spectrum of this star. Broad emission lines of highly ionized species like C III and O VI were detected, well above the low continuum level. It has been suggested that they may originate either from a solar-like extented chromosphere or from magnetospheric accretion. Besides, O VI emission lines provided enough background flux to show that the total mass of H2 available in the line of sight to Beta Pictoris is much smaller than what was expected from ISO observations (Thi et al. 2001). A tentative explanation to reconcile both sets of data is that H2 is distributed in clumps instead of being uniformly distributed in the CS disk. This, in turn, shows the need of further observations to clarify the processes occuring in the late stages of the planetary formation and the dissipation of the molecular gas from which planets form. Hence, we propose two deep exposures on the Beta Pictoris system with two main goals - first, the higher signal-to-noise ratio will allow us to search for H2 at an unprecedented sensitivity; second, the analysis of the emission line profiles and variability will allow to understand the physical mechanism responsible for the gas heating. Proposal ID: C134 Principal Investigator: De Marco, Orsola Institution: American Museum of Natural History Proposal Title: The Nova-Dwarf Nova Connection The extraordinary discovery that thermonuclear runaway (TNR) processed material lives on the white dwarf (WD) surface in the dwarf nova (DN) system VW Hyi is in direct conflict with the currently accepted model for DNe. The WD in VW Hyi should be continuously buried in solar-abundance material accreted from its fully-convective, low-mass main sequence companion. IT ISNT. There are either subtle metallicity-varying forces at work, or the current theory of DNe is completely wrong. Only by monitoring the abundances of key elements throughout an entire dwarf nova cycle will we be able to observe the rate of change of key abundance ratios by accretion and mixing processes, and hence deduce the relative importance of diffusion (in removing metals), accretion (in adding metals) and (non-party line but possible) local nuclear burning. FUSE is ideal for this task, because its spectral range contains key lines of important elements, because of its high temperature sensitivity and because in its wavelength range, the VW Hyi spectrum is totally dominated by the WD. VW Hyi is the obvious candidate for this project, because we already know that its abundances are indicative of recent TNR processing. Proposal ID: C138 Principal Investigator: Ake, Thomas B. Institution: Johns Hopkins University Proposal Title: Atmospheric Eclipsing Binaries HR6902 and 22Vul We propose to perform a comparative study of the atmospheric eclipsing binaries HR 6902 and 22 Vul. Each of these is comprised of a luminous G-type primary with a late B main sequence secondary. The eclipsing nature of these systems allows a determination of the physical conditions in the outer atmospheres of the evolved primary components. The G stars are on different sides of the cool star dividing line between coronal and non-coronal stars. HR 6902 has a thin chromosphere and a hot, low mass-loss wind, seen in C IV and Si IV absorption when the B star passes behind the primary. 22 Vul, on the other hand, shows extended absorption far from the star and a cool, high velocity wind of approx. -200 km s^(-1). It is more like the classical zeta Aur systems, but the Fe II wind lines have peculiar profiles, likely owning to the effects of the radiation field of the hot star. Although located close to each other on the HR diagram, there are fundamental differences in the outer layers of these stars. We propose obtaining FUSE exposures during partial and total eclipse phases to study the kinematics and structure of the transition regions and winds of the primary stars and relate them to other FUSE observations of single objects. These observations will also be of use in understanding the complex spectra of other, interacting binary systems, where the stellar components are embedded in much denser material due to mass transfer effects. Proposal ID: C140 Principal Investigator: King, Nichole Institution: Space Telescope Science Institute Proposal Title: FUSE Observations of Massive Evolved Stars in the LMC We propose to observe late-type Wolf-Rayet stars, Luminous Blue Variables, and luminous hot P Cygni type stars in the LMC with FUSE. These massive (M_initial > 30 M_odot) evolved stars have high mass-loss rates and complex atmospheres, making them difficult for stellar evolution models (and hence isochrones) to reproduce. The situation can be improved by providing evolution theorists with observationally derived fundamental stellar parameters such as luminosities, effective temperatures, terminal wind velocities, mass-loss rates and atmospheric abundances of hydrogen burning products. With FUSE we can observe these stars near the effective peaks of their spectral energy distributions - there, spectral emission-lines of CIII, NIII, SiIV, PV, and PIII, and a multitude of blended FeIV or FeIII features are present. These data, when combined with optical spectroscopy will be modeled using the latest version of the non-LTE, line-blanketed, geometrically extended, expanding atmosphere code of Hillier & Miller (1998, 1999) to estimate the fundamental stellar parameters listed above. The addition of the FUSE spectral range rigorously tests the synthetic models as the FUV region is extremely sensitive to line-blanketing. The FUSE data extend the observed range of ionization states and provide additional resonance lines to constrain mass-loss rates and terminal velocities. In summary FUSE will facilitate more accurate stellar parameters for these stars. These parameters are important for developing the post-main sequence portion of massive stellar evolution models. These models are in turn used to generate the isochrones which are used to estimate ages of populations in star forming galaxies. Additionally, the data from this project will allow us to estimate the photoionization rates of these stars, and their wind kinetic energy, momentum, and chemical yields to the ISM with some assumptions. Proposal ID: C141 Principal Investigator: Young, Peter R Institution: Harvard-Smithsonian Center for Astrophysics Proposal Title: RR Tel getting under the flux limit -- an observation with FUSE The symbiotic star RR Telescopii holds a special place amongst UV spectroscopists due to the extraordinary richness of the emission line spectrum emitted by the nebula around the system, which has proved to be an extremely fruitful laboratory for both plasma modeling and line identification. FUSE will obtain, for the first time, a high spectral resolution spectrum in the 900-1100 A region at high sensitivity. RR Tel has not previously been considered for observing with FUSE on account of the O VI line fluxes being well above the FUSE flux limits. A way to observe RR Tel safely with FUSE by only obtaining spectra through the SiC channels is outlined in the feasibility section that follows. Proposal ID: C149 Principal Investigator: Prochaska, Jason X. Institution: Carnegie Observatories Proposal Title: Identifying the Physical Nature of Low z O,VI Absorbers Earlier this year we initiated a program to investigate the physical nature of low z O VI absorption lines, systems which may contribute significantly to the cosmological baryonic budget. The principle goal of this program is to establish and examine the association between O VI gas and galactic haloes, galaxy groups, clusters, or other large-scale structures (e.g. filaments) through the synthesis of two observational projects - (1) the analysis of high SN FUSE spectra of extragalactic sources for z < 0.15 O VI systems; and (2) a large ground-based galaxy survey with the WFCCD at Las Campanas Observatory. We propose to obtain high-SN FUSE spectra of four moderate redshift AGNs to catalog O VI systems along these sightlines to a 3-sigma limiting EW of 30 mA. The proposed observations will increase the redshift path for O VI by approx. 50 percent and significantly improve the cosmic scatter in the current FUSE database. We have obtained galaxy redshifts (to 95 percent completeness limit at R < 19.5) for fields around two of these sight lines and have been awarded further observing time for the other two in the fall. The combination of high-SN FUSE spectra and ground-based optical redshifts for these sightlines will allow a detailed study on the nature of this very important reservoir of ionized gas at low redshift. Proposal ID: C150 Principal Investigator: Shrader, Chris Institution: NASA Goddard Space Flight Center Proposal Title: Far UV Spectroscopy of X-Ray Novae We propose to obtain Far-UV spectroscopic observations of X-Ray Nova events selected on the basis of their optical-UV brightness and absorption characteristics. A recent case, XTE J1118+480, represents an excellent candidate to achieve our goals if it or becomes active during FUSE Cycle 3. Specific goals for FUSE include simultaneous measurement of the ionizing X-ray flux and the strengths of O VI, C III, and N III lines. These measurements can then be applied as density, temperature, optical depth, and abundance diagnostics within the context of photoionization model calculations. In addition, we will search for variability on time scales of seconds, resulting, for example, from reprocessing of an X-ray flare in an accretion disk, as well as excess low-frequency power-density in continuum and line components. If approved, our observations will be executed in coordination with a number of supporting observation programs on space and ground-based facilities. Proposal ID: C151 Principal Investigator: St-Louis, Nicole Institution: Universite de Montreal Proposal Title: A Systematic Study of Colliding Winds in WR Stars. I. The Very-Short Period WC+O Binary HD36521 We propose to secure a time sequence of ultraviolet (UV) spectra for the shortest-period WC+O binary system known, HD36521 (P1.9 days) to study the physical parameters and the structure of the bow shock zone formed when the winds of the two hot stars collide. Of particular importance in the FUSE UV range is the presence of a broad spread of emission lines with different ionization levels, ranging from O VI to C III. These lines are expected to arise in the bow shock zone at progressively larger distances from the X-ray heated bow head, as the compressed plasma flows outward along the shock cone and cools. The study of how these lines vary with orbital phase will allow us to map out the structure and kinematics of the bow shock. This in turn will provide useful constraints on the basic parameters of the winds as well as the collision process itself. HD36521 is known to show strong wind-wind collision effects. Among the 4 known WC+O binaries observable with FUSE, this is the last one to be examined. We will compare its behavior with our data already obtained for the other three systems. Proposal ID: C152 Principal Investigator: Keyes, Charles D. Institution: Space Telescope Science Institute Proposal Title: Outbursts in Symbiotic Binaries Z And Continued Observation To study the accretion and outbursts in symbiotic systems, we organized a multi-wavelength, target-of-opportunity (TOO) observing program including FUSE cycle 2, Chandra, XMM, and the VLA. The prototype symbiotic, Z And, entered its largest outburst in decades in September 2000 and has been observed at several epochs with all of these instruments. We propose to continue FUSE observation of Z And at two epochs in cycle 3 as the outburst declines from maximum to the important quiescent state. The evolution of the X-ray and UV spectrum throughout the outburst will play a vital role in distinguishing between the outburst models currently in contention for describing outburst behavior. Emission line strengths of the FUSE-band species, especially when combined with lines of the same species from the other spectral regions, will provide diagnostics of the colliding windshock region. The high-resolution of FUSE-band absorption features will provide a unique opportunity to probe several aspects of the outburst material. Note especially that FUSE provides important information for the analysis of the x-ray data as FUSE observations of HI absorption are at sufficiently high resolution to allow the separation of the interstellar component from the systemic component of the absorption. Proposal ID: C153 Principal Investigator: Shelton, Robin L. Institution: Johns Hopkins University Proposal Title: Using FUSE to Measure the Galactic Halos O VI Intensity Ultraviolet resonance line emission from O VI ions in the diffuse interstellar medium has been detected unambiguously by FUSE. The results have been used to estimate the average conditions electron density and thermal pressure) along two lines of sight through the local hot gas and Galactic halo. Here we propose to distinguish local O VI emission from Galactic halo emission using the shadowing method. The results of the proposed observation will provide crucial insights into the conditions and dynamics of the hot gas in the Galactic halo. The combination of the proposed observation with previously approved FUSE and XMM observations will provide the necessary information with the minimum additional exposure time. Proposal ID: C154 Principal Investigator: Gull, Theodore Institution: NASAs GSFC Proposal Title: Eta Carinae Probing for the Physics Eta Carinae, the best-known Luminous Blue Variable (LBV), continues to confound astronomers as to what drives its historical outbursts and periodic changes. Is Eta Carinae a single star or a binary system In the past four years, determination of a spectroscopic 5.5-year period led to coordinated observations throughout the spectrum that confirmed the periodicity. While the evidence leans heavily towards a binary system, direct evidence of a companion star is yet to be found. An alternative explanation is that Eta Carinae is a single star near the Eddington limit undergoing periodic mini-explosions. One possible way to differentiate the two models is monitoring of the FUV with FUSE through the next spectroscopic minimum, predicted to be 2003.5. As part of that monitoring activity, we request two 0 ksec observations during Cycle 3. Proposal ID: C155 Principal Investigator: Owocki, Stan Institution: Univ. of Delaware Proposal Title: The Physical Conditions in Grand Design Stellar Wind Variability We propose to use the unique capabilities of FUSE to monitor the time-dependent behavior of the stellar wind profiles in two O7 supergiants, one in the LMC and one in the SMC. These observations will enable us to examine the physical properties of co-rotating interaction regions (CIRs). Specifically, we will (1) observe how the state of wind material changes when CIRs traverse the stellar surface; 2) perform a meaningful search for ionization changes due to these structures; and (3) determine how wind activity is affected by metallicitymass loss rate. A previous FUSE monitoring campaign has shown that stellar wind variability in an LMC O4 supergiant is similar to that in its Galactic counterpart. However, because the winds of early O stars are not strongly affected by CIRs, we now seek to extend the observations to O7 stars. Galactic O7 stars show the strongest temporally coherent wind variability, which is normally interpreted as CIRs. The new observations will enable us to focus on CIR-related variability and thereby provide the data necessary to constrain models of CIRs, which are rapidly becoming a paradigm in the field. Proposal ID: C157 Principal Investigator: Peters, Geraldine J. Institution: University of Southern California Proposal Title: A Study of the High Temperature Polar Plasma in B-Type Interacting Binaries FUSE observations of the interacting binaries V356 Sgr (B2V + A2II) and TT Hya (B9.5Ve + K1III-IV) in Cycle 1 at several phase points during totality revealed the presence of broad O VI emission that was especially strong in V356 Sgr. The high temperature plasma that produces this emission is presumably located at the base of the polar jets in these systems that were detected from HST-FOS spectropolarimetry. In order to determine physical conditions in the jet and obtain information on its geometry and formation, we propose new FUSE observations of V356 Sgr, TT Hya, and a comparison system RY Per (B3V + F6III). New observations of V356 Sgr will provide information on whether the O VI emission is concentrated near the site where the gas stream impacts the primary or if it emanates from an extended region and will enable one to assess whether the jet is a stable structure. Since the Cycle 1 observations revealed that the O VI Si III, and other emission lines vary during totality in V356 Sgr, we request a continuous set of FUSE exposures throughout the 10.2 hr eclipse that include the ingress and egress phases. Observations of RY Per throughout its 2.3 hr total phase are proposed to investigate the effect of binary separation on the polar plasma, as it has similar component stars to those in V356 Sgr but a shorter period. To remove the contribution from the strong ISM lines, mostly H_2, that pervade the emission features, we request a single observation of each star outside of eclipse. Proposal ID: C158 Principal Investigator: Peters, Geraldine J. Institution: University of Southern California Proposal Title: Heavy Element Abundances in Two B0-B0.5 Main Sequence Stars in the Small Magellanic Cloud We propose FUSE observations of AV304 (B0.5V) and NGC346-637 B0V), two sharp-lined main-sequence stars in the Small Magellanic Cloud, to determine the abundances of heavy elements, especially those of the iron group. The FUSE spectral region contains numerous Fe III lines, including the resonance multiplet (UV 1) near 1130 Angstroms, that is excellent for abundance determinations and two strong multiplets of V III, an ion that does not produce measurable lines longward of 1200 Angstoms, in metal-deficient stars. In addition there are several measurable lines from Cr III and Mn III. A limited analyses of ground-based spectra of these stars by Dufton et al. (1990) and Rolleston et al. (1993) indicated an average underabundance of 0.7-0.8 dex for most light elements and a recent analysis of HSTSTIS data on AV304 by Peters & Grigsby (2001) suggests that the Fe group elements are depleted by the same amount relative to the sun. When combined with the HST-STIS results, this effort will represent the first attempt to measure the abundances of Fe group elements in the photospheres of early B, main sequence stars in an external galaxy. Although abundances of the Fe-peak elements are of interest because they are important for assessing opacities for stellar evolution calculations and the validity of theoretical calculations of explosive nucleosynthesis, the ground-based study did not yield this information because measurable lines from these species are found only in the UV spectral region. Abundances and abundance ratios of both heavy & light elements will be compared with the HST-STIS results from AV304, H II regions, supernova remnants, evolved massive stars in the SMC, and theoretical calculations of nucleosynthesis. Proposal ID: C160 Principal Investigator: Massa, Derck Institution: Goddard Space Flight Center Proposal Title: The Metallicity Dependence of the Bistability Jump in Hot-Star Winds The theory of hot-star winds predicts that the structure of the outflow changes abruptly near a specific stellar temperature. This transition in wind properties is called the bistability jump, and occurs when the quality of the stellar radiation field causes a major shift in the ionization state of the abundant metals that drive the wind. For example, the jump occurs near B1 for Galactic stars, when the dominant ionization stage of Fe in the subsonic region of the atmosphere switches from Fe IV in the hotter stars to Fe III in the cooler ones. The result of the transition is that stars on the cooler side of the jump have more massive, denser, and slower winds. Theory predicts the location, magnitude, and metallicity dependence of the jump. Observations of these quantities will constitute significant tests of the theory, and will provide important observational feedback to the models. The Magellanic Clouds provide an ideal laboratory for mapping the location of the bistability jump in the H-R diagram and its dependence on metallicity. Furthermore, the far-UV is the ideal spectral region to search for the effects, since it contains a wealth of resonance line diagnostics that span a wide range of ionization potentials. We therefore propose to use FUSE to observe early B supergiants in both the Large and Small Magellanic Clouds, in order to determine empirically the metallicity dependence of the temperature at which the bistability jump occurs, and to estimate its impact on the velocity field of the wind and the mass flux it carries. Proposal ID: C161 Principal Investigator: Barrett, Paul Institution: Space Telescope Science Institute Proposal Title: Time-resolved spectroscopy of high field polars A long sought-after group of polars are those with high magnetic field >60 MG), because they may provide valuable clues to the structure and dynamics of accretion in strong magnetic fields and the evolution of CVs in general. The discovery of several soft X-ray polars by ROSAT and their subsequent identification as high field polars supports the conclusion that the bremsstrahlung is suppressed at higher fields and cyclotron cooling predominates. We propose time-resolved FUV spectroscopy of high field polars to study their accretion kinematics, their high excitation lines (e.g. O VI, O IV, and Si IV), and the distribution of gas in the binary. Proposal ID: C162 Principal Investigator: Barrett, Paul Institution: Space Telescope Science Institute Proposal Title: Time-resolved spectroscopy of eclipsing polars Eclipsing polars have long provided important information about the structure and dynamics of magnetic cataclysmic variables by providing precise information about the location of the emitting gas within the binary system. Previous such studies have shown that the X-ray emission is located on or very near the white dwarf surface, while the optical and near-UV emission is predominantly from the surface of the secondary star. We propose time-resolved observations of several eclipsing polars to better understand the far UV emission in these binaries. The combination of eclipse mapping and doppler tomography will enable us to make detailed maps of the accretion stream and to better understand the formation of the high excitation lines. FUSE with its high time and spectral resolution and good sensitivity is an excellent means for accomplishing these objectives. Proposal ID: C163 Principal Investigator: Shastri, Prajval Institution: Indian Institute of Astrophysics Proposal Title: Geometry of hot outflows in Seyfert galaxies We propose to attack the question of whether orientation plays a dominant role in the observed hot gaseous outflows in Seyfert galaxies. We plan to do this by contrasting the properties of the O VI absorbers in a matched sample of Seyfert 1s and 2s, which, in the framework of the Unified Scheme, are oriented face-on and end-on respectively w.r.t. us. The O VI emission line is present in all Seyferts, and is a unique characterizer of the kinematics of gas at T approx. 10^6 K. The spectral sensitivity and resolution of FUSE in this range makes it possible to discern the different components of the absorbing outflow. The key points of our investigation are (a) the Seyfert 1s and 2s have been chosen to be intrinsically similar, and thus provide a very clean statistical comparison of face-on and end-on Seyferts and therefore a rigorous test of orientation effects, and (b) all the Seyfert 1s and three of the Seyfert 2s are already observed by FUSE, so that only five more targets are required to complete FUSE observations for this unique, well-matched sample of 16 Seyfert galaxies. Proposal ID: C164 Principal Investigator: Korpela, Eric J. Institution: University of California, Berkeley Proposal Title: Investigating OVI emission in the Eridanus Superbubble. The Eridanus superbubble has been called the Rosetta Stone of superbubbles because virtually all of the processes which shape the interstellar medium are taking place somewhere within its boundaries. One of the features of this region is the Eridanus Soft X-ray enhancement. It is understood that this enhancement is a region of hot (> 3x10^6 K) gas that fills the Eridanus cavity. We propose to investigate two lines of sight for O VI lambda lambda 1032,1038 emission, one which intersects an optically thick neutral cloud located within the X-ray emitting region and one which does not intersect the cloud. The observation of the line of sight not intersecting the cloud, combined with a Cycle 2 archival absorption measurement of a QSO on a very nearby line of sight, will allow us to accurately determine the physical properties of 10^(5.5) K gas within the superbubble. The line of sight intersecting the cloud will provide additional information about the physical location of the emitting regions and the interface between the cloud and the hot gas in which it is embedded. These data will allow us to distinguish between contrary theories of the structure of the ISM and energy transport mechanisms that occur within it. Proposal ID: C168 Principal Investigator: Bruhweiler, Frederick C. Institution: The Catholic Univ. of America Proposal Title: The NGC6164-5 & Rosette Nebulae Tests of the Theory for Interstellar Bubbles Both the O star, HD148937, and the O stars of the Rosette Nebula are embedded in extremely young wind-blown interstellar (IS) bubbles. The ages of these bubbles are less than 10^5 yr, much younger than the central O stars. These ages are also far too young compared with theoretical predictions for IS-bubbles. We will use FUSE to observe the O stars in these two IS-bubbles. FUSE allows us, for the first time, to go beyond heuristic calculations and make detailed comparisons with theoretical models. We will obtain column densities of interstellar species not accessible from HST and IUE. We will use column densities and the deduced velocities of the species, C II, C III, N II, and N III, together with those from HST and IUE data, to provide reliable estimates of the total mass in the expanding shells of the IS-bubbles. We will also search for O VI at velocities of the conductive interfaces of the expanding shells encompassing the hot cavities. We will use the derived NC ratio for the H II region around HD148937 to ascertain if this gas is N-rich and whether it is composed largely of outflow from an earlier red supergiant evolutionary phase of HD148937. The implications of this study are far-reaching. Stellar winds are one of the primary energy inputs for the ISM and are extremely important for determining the Galactic filling factor for the hot component to the ISM as well as understanding galactic morphology and evolution both now and in the Early Universe. Proposal ID: C169 Principal Investigator: Espey, Brian Institution: Space Telescope Science Institute Proposal Title: FUSE Cycle 3 observations of the EG-AND eclipse ingress phases EG-AND is symbiotic binary which is bright in both optical and UV, and shows little evidence for dust along the line of sight, making it an ideal candidate for FUSE. EG-AND has never been observed in outburst, but its brightness permits the detection of its outflowing wind v_infty approx. 500 km per sec, and dot-M approx. 5x10^-8 M_odot). During periodic occultations by the giant primary, the signature of Rayleigh scattering is strongly evident in the UV. At such times the white dwarf continuum provides a background source against which the outer layers of the relatively cool giant can be observed. Unlike massive binaries, the winds of a symbiotic system have very different characteristics -- the hot wind is relatively thin and fast, whereas the cool wind is slow and weakly ionized -- and hence they can be isolated spectroscopically. The far-UV region of the spectrum is rich in a range of permitted and semi-permitted lines ranging from low to high excitation, and also containing the molecular features of H_2, thus permitting the diagnosis of material from the base of the giants wind, the white dwarf wind, and the hot, shocked, material where the two interact. Phase-resolved spectra thus provide the unique tomographic information we require to model these systems and understand how the winds are generated and interact. For all these reasons, EG-AND is a prime target for FUSE if we wish to understand wind formation in both white dwarfs and cool giants. These observations are also vital for testing line-driven wind theory. Proposal ID: C171 Principal Investigator: Nichols, Joy Institution: Smithsonian Astrophysical Observatory Proposal Title: Study of the Elongated Superbubble Around Cyg OB1 The Cyg OB1 superbubble is apparently formed by the merger of several smaller superbubbles that were produced by non-coeval evolution of the parent stellar association. Such non-coeval evolution of clusters and associations may be common, but the Cyg OB1 superbubble is the best example for detailed study because of its proximity, relatively young age, and the presence of the parent association. We propose to observe several stars that are members of the parent association, sampling lines of sight toward the full spatial extent of this elongated superbubble to obtain absorption line measurements of O VI. We will use the O VI data collected by FUSE to map temperature and shock parameters in these various neighborhoods of the Cyg OB1 superbubble. The observational data, combined with the calculated energy budget, will be used to model the time-dependent multi-bubble evolution of this superbubble. Proposal ID: C172 Principal Investigator: Iping, Rosina Institution: Catholic University of America Proposal Title: The Hot ISM of the Antennae - The Nearest Galaxy Merger NGC 4038-9 (the Antennae) is the nearest ongoing galaxy merger and a prototype of the much more frequent galaxy collisions seen at high redshifts. Recent Chandra observations confirm the existence of a substantial hot soft-X-ray halo around the system, and clearly delineate the locations of very hot gas associated with the moderate starburst ongoing in the system. Observations of HI 21 cm, CO, and H alpha emission have been used to explore the dynamics and kinematics of the cooler gas in the system, both in the tidal tails and in the star forming regions. However, little is known about how the very hot gas is heated, particularly in the halo, or about the ISM and detailed connections between the interaction process, enhanced star-formation, and heating of the X-ray emitting gas. We will use FUSE absorption spectra to probe the kinematics and composition of the hot and warm ISM along three sightlines, through three different regions of the NGC4038-9 halo, to different regions in the galactic disks. Pointings have been selected to probe regions with different starburst ages, different X-ray and H alpha emission properties, and different halo gas properties. We will search for O VI in both emission and absorption, and will use OVI with other shock heated species, to determine the distribution, composition, and dynamics of the hot (approx. 3x10^5 K) halo gas and of hot gas in the disks. In the same observations, we will use measures of the warm (approx. 10^4 K) gas in the HII regions to determine and compare abundances, physical properties, and bulk motions of the material associated with three different star-forming regions. We will also make direct measures of the amount of diffuse H_2, the dominant component of the ISM, in different regions of the merger system. Proposal ID: C176 Principal Investigator: Iping, Rosina Institution: Catholic University of America Proposal Title: Ionization Structure of the High-Excitation Planetary Nebula NGC 7009 The high-excitation planetary nebulae NGC 7009 and its central star were observed with FUSE through the 30x30 arcsec slit as an Early Release Observation in 1999 Nov. The spectrum shows strong emission from He II, C III, N II, N III, S III, S IV, S VI, and several unidentified features superposed on the continuum of the hot central star. We propose to use the 4x20 arcsec slit to isolate the inner and outer parts of the nebula without the central star to study the large number of lines expected from the nebula with much better spectral resolution. We also hope to study several key emission lines, including O VI 1032-38 and S VI 933-44, that are masked or absorbed by the stellar spectrum in the earlier observation. The C III 1175 and Ne VI multiplets should provide good density diagnostics of the hot gas. The central star will also be reobserved with the narrower slit to obtain its spectrum with higher spectral resolution (approx. 30 kms) and with significantly reduced contamination from nebular emission. Proposal ID: C177 Principal Investigator: Werner, Klaus Institution: Universitat Tubingen Proposal Title: Temperature scale and metal abundances of hot hydrogen-rich central stars of planetary nebulae The temperature scale of the hottest central stars of planetary nebulae is poorly known. FUSE FUV spectra in combination with HST UV observations will allow precise temperature determinations by utilizing ionization balances of C III, C IV and O V, O VI lines. We have established a sample of eight stars for which we are currently obtaining HST spectra. The sample comprises hot hydrogen-rich central stars covering the hottest phase of post-AGB evolution (T_eff > 70,000K). The spectra shall be analyzed with fully metal line blanketed NLTE model atmospheres in order to determine T_eff, surface gravity, and chemical composition. Besides the temperature scale the results will address the following problem - Depending on the particular star, the metal abundances are either dominated by current diffusion processes or they originate from dredge-up phases during previous AGB evolution. We expect that our sample comprises different objects allowing both processesphases to be studied in detail. a.) Those objects, which show qualitatively a metal abundance pattern which points at dredge-up phases, can be used to quantitatively check against abundance predictions of stellar evolution theory. b.) The other objects, where gravitational diffusion and radiative acceleration determine the photospheric metal abundances, will be used to check our NLTE models which for the first time include diffusion processes self-consistently. Proposal ID: C178 Principal Investigator: Rauch, Thomas Institution: Universitat Tubingen Proposal Title: Exploring the evolutionary status of the O(He) stars The O(He) stars are found in the post-AGB region of the HRD, just amongst the PG 1159 stars. In contrast to the latter, they do neither show carbon nor oxygen lines in their optical spectra but exhibit almost pure He II absorption-line spectra. Thus, two possibilities are conceivable to interpret their evolutionary status Either they are direct PG 1159 progenitors and ongoing mass loss due to a stellar wind will take off the remaining He-rich envelope and lay free carbon- and oxygen-rich material at their surface. Or they just experienced a less efficient mass loss on the AGB and define a new evolutionary channel into the DO white dwarfs. The proposed FUV spectroscopy aims to determine the mass-loss rates and C and O abundances of all four presently known O(He) stars for the first time. This will allow to constrain their further evolution Significant higher mass-loss rates than predicted by radiation-driven wind theory might turn the O(He) stars into PG 1159 stars.