05/28/02
SEGRANSAN Damien Observatoire de Geneve; LAOG
51 Chemin des maillettes SF2A-
CH-1290 Sauverny, Suisse
Presentation 1 : Invited
Will differential closure phase allow direct detection of hot jupiter
Damien Segransan
The main difficulty to detect photons from exoplanets, even strongly irradiated, is the very high contrast between the planet and the parent star. This contrast, even in the most favorable case (51Peg b, Tau Boo b), is estimated to be 10^4-10^5 in the J, H and K band but remains uncertain due many unknowns about planet's atmospheres. The VLTI/AMBER will have sufficient angular resolution to detect a few Hot Jupiters but the planet signature will be extremely low which translates into fringe amplitude and phase (radian) change as low as 10^(-4) - 10^(-5). In this presentation, I assume that the VLTI/AMBER-3T instrument is stable enough to allow such detection and I will show that differential closure phase and amplitude allow to calibrate atmospherical effects (differential dispersion, piston) and instrumental effects up to the beam recombination with the required accuracy. Direct detection of Hot Jupiter with the VLTI may be done and must absolutely be attempted in the next few years.