Direct Imaging, Detection and Characterization of Planets and Brown Dwarf
Gaël CHAUVIN
LAOG
Résumé :
With the development of high contrast imaging techniques and
infrared detectors, vast efforts have been devoted during the past
decade to detect and characterize lighter, cooler and closer companions
to nearby stars, and ultimately image new planetary systems.
Complementary to other observing techniques (radial velocity, transit,
micro-lensing, pulsar-timing), this approach has opened a new
astrophysical window to study the physical properties and the formation
mechanisms of brown dwarfs and planets. In this talk, I will briefly
present the observing challenge and needs associated to the direct
imaging of faint companions to bright stars. I will describe the
different observing techniques and strategies used from space and
ground-telescopes and the main samples of nearby stars selected to
conduct these deep imaging surveys. I will summarize the main results
obtained sofar about the detection of substellar companions down to the
planetary mass regime, the characterization of their physical properties
and of their cool atmospheres as well as the current detection
performances obtained in terms of mass and physical separation. Finally,
with the next generation instruments, dozens of exo-planets are expected
to be imaged around 2011. In complement to other techniques, the
increased number of direct imaging detection will enable comprehensive
studies of the exo-planets statistical properties to strongly improve
our understanding of their formation and evolution, their relation to
disks and brown dwarfs companions and, ultimately, their chemical
composition and internal structure.
