Résumé / Abstract Seminaire_IAP
« Discovery and Characterization of Transiting Extrasolar Planets »

Peter McCullough
Space Telescope Science Inst. (STScI) (Baltimore, Maryland, Etats-Unis d'Amérique)

In the past decade, one of the fastest growing fields of astronomy has been the discovery and characterization of planets that pass in front of (or "transit") their host stars. From telescopes in backyards to ones in space, observations of our "XO Project" and many others around the globe are contributing to this burgeoning field of inquiry (e.g. discovery of the transit of the 111-day-period HD80606b).
I will review highlights from some recent programs that I have had a role in, using the HST, SST, and WIYN telescopes. In particular, time series photometry of high precision with the Spitzer IRAC instrument have challenged the prevailing hypothesis for the formation of hot stratospheres of such planets (XO-1b, XO-2b, and XO3-b). Ground-based time-series photometry with a precision of 200 ppm per minute, as demonstrated on XO-2 with the WIYN 3.5-m, show promise for discovering transits of super-Earths discovered by radial velocities. Time series of spectrophotometry with Hubble's NICMOS instrument have provided initial glimpses to the atomic and molecular content of transiting planets' atmospheres (HD189733b, XO-1b).
Prior to the May 2009 servicing mission of HST, we used one of HST's fine guidance sensors, FGS-2r, as a photometer to observe the transiting planet host star HD17156 for ten straight days with a precision of 120 ppm per minute. We derived the mean density of the star by two independent methods, the transit technique and asteroseismology, and find they agree, thereby validating the two methods. I will also discuss some likely future developments enabled by precise observations from space (Kepler, Hubble, Spitzer) and the ground.
vendredi 18 juin 2010 - 11:00
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage