Number 19 March 2002
Contents:
1) FUSE Science Operations have Resumed
2) Target changes for accepted, low Declination, programs
3) Observatory Programs (Supplementary Targets)
4) CalFUSE News
1) FUSE Science Operations have Resumed
After the recent downtime due to reaction wheel failures, we are pleased to
announce that FUSE is back in business! In late January, new control software
was uplinked that enabled three-axis control using two reaction wheels plus
magnetic torquer bars. February was spent performing a combination of tests and
science observations, and in March we have transitioned back into full time
science mode, with occasional tests still needed to enhance our capabilities
further.
Our primary limitation at the moment is sky coverage, with regions above
declination +40 (or below -40) degrees available for normal scheduling during
a 60-day precessional cycle. We are hopeful that some capability to observe
lower declinations can be developed over the coming months, but development
and testing of these techniques will take time.
We acknowledge the work of many people at JHU, NASA/GSFC, Orbital Sciences
Corp., and Honeywell Technical Services, Inc., who have made the FUSE recovery
a reality. It was a real team effort!
2) Target changes for accepted, low Declination, programs
The FUSE satellite is back on-line and performing science observations
after the recent downtime due to reaction wheel failures. The "new FUSE"
maintains the same scientific capabilities as before in terms of sensitivity
and spectral resolution. However, there are aspects of operations that have
become much more complicated and in some aspects limiting. For all users with
unobserved targets awaiting execution, we are requesting a reassessment of
their target selection and that they consider modifications that may be in the
best interest of both them and the project.
Earlier this month, notifications and details of these target changes
were distributed by the Project Scientist (George Sonneborn) and the FUSE Chief
of Observatory Operations (Bill Blair). The text of these messages can be found
at:
http://fuse.pha.jhu.edu/users/gs_call.html
and
http://fuse.pha.jhu.edu/users/wpb_inst.html
respectively. Many observers have already responded, and the submitted target
changes are currently being evaluated. We expect to notify the PIs and
implement the accepted changes in early April. While the deadline for the
first go-around of target changes, including possible target allocation issues,
has passed, we would like to emphasize that we will be accepting further target
change requests on a continuing, case-by-case basis. There will however be a
hiatus on target changes once the cycle 4 NRA is released this summer.
3) Observatory Programs (Supplementary Targets).
To help maintain high scheduling efficiency of scientific observations,
we have instituted a class of "Observatory Programs". These programs are made
up of targets at high declinations that are not currently allocated to any
approved program, but which are of scientific interest. The Observatory
Programs will be used to fill any gaps in the observing schedule, but only when
no regular approved target is available. These targets will have program
ID Z9nn. Any data obtained for these programs will have no proprietary period
and will be placed in the public archive immediately after processing.
To ensure a rapid turn-around, a first set of Observatory Programs
have been defined and implemented by the FUSE User Support Group, with the
approval by the NASA Project Scientist. These first programs were selected to
provide survey data complementing existing programs, or to provide flux
measurements of target classes where such data are lacking.
This first set of Observatory Programs consists of 6 programs with a
total of about 250 objects. The six programs are aimed at:
1) FUSE Observations of stars in the NWU HST snapshot survey,
2) A survey of Algol binaries,
3) A survey of White Dwarfs from the McCook and Sion Sample.
4) A survey of O-B subdwarfs.
5) A complementary sample of LMC (ISM) sightlines
6) A survey of Herbig Ae/Be stars
The FUSE web site:
http://fuse.pha.jhu.edu/users/observe_pro.html
contains a list of the programs with some further description, as well as the
rules applicable to these programs and targets. We are finalizing a page
on the JHU web site on which we will keep an updated list of the targets
observed under these programs. As these observations are released immediately
upon satisfactory processing and quality control, we note that you can also
keep abreast of these observations by regularly searching the MAST archives for
program IDs Z9**.
A number of suggestions for further Observatory Programs have already
been received from the community. The originators of these programs should
expect a letter from the NASA Project Scientist in the near future finalizing
the constraints, requirements and agreements for possible selection.
Suggestions for additional Observatory Programs are still being
solicited. Suggestions of programs or targets to be added to this list should
be sent to fuse_support@pha.jhu.edu.
4) CalFUSE News
We expect to release v2.1 of CalFUSE, the FUSE calibration pipeline, in
early April. This version of the code features improved background calibration
files and a new module that stretches the bad-pixel map to account for
time-dependent changes in the Y scale of the detector. A number of bug fixes
(most are minor) developed over the past few months are also included. For
details, please see "Introduction to CalFUSE v2.1" at
http://fuse.pha.jhu.edu/analysis/calfse_intro.html
In the near future, we will begin processing all new FUSE data with
CalFUSE v2.1. Once that is working, we will re-process the entire FUSE data set
with the new pipeline. We expect to upgrade the entire FUSE archive at MAST
with data processed with CalFUSE v2.1 by the end of the year.
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The Observer's Electronic Newsletter is published by the FUSE project and is
aimed at the FUSE user community.
Editor: B-G Andersson, FUSE Guest Investigator Officer.
The FUSE Project is managed by Johns Hopkins University's Center for
Astrophysical Sciences in Baltimore, MD, for NASA's Goddard Space Flight
Center. The FUSE Principal Investigator is Dr. Warren Moos, the FUSE Project
Manager at JHU is Mr. J.B. Joyce, and the NASA Project Scientist for FUSE
is Dr. George Sonneborn.
Further information about the FUSE Guest Investigator Program can be
obtained from: Dr. George Sonneborn;
sonneborn@stars.gsfc.nasa.gov
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