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Spectroscopic follow-up of transiting exoplanet surveys FLAMES follow-up of OGLE III. Frédéric Pont (Geneva) Francois Bouchy (Mar seille), Claudio Melo (ESO), Nuno Santos (Lisbon), Didier Queloz, Stephane Udry, Michel Mayor (Geneva). 10. 7 known transiting exoplanets. HD 209458 TrES-1
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Spectroscopic follow-up of transiting exoplanet surveysFLAMES follow-up of OGLE III Frédéric Pont (Geneva) Francois Bouchy (Marseille), Claudio Melo (ESO), Nuno Santos (Lisbon), Didier Queloz, Stephane Udry, Michel Mayor (Geneva)
10 7 known transiting exoplanets HD 209458 TrES-1 OGLE-TR-10 OGLE-TR-56 OGLE-TR-111 OGLE-TR-113 OGLE-TR-132 mass-radius relation for hot gas giants
The OGLE-III program Ground-based photometric survey for planetary transits ~100’000 targets / square degree 177 transiting candidates in the Galactic disc Rc RJupiter Pc : 0.8 - 8 days V : 15-18 mag : 5-15 mmag spectroscopic follow-up requires large telescope and <100 m/s accuracy Udalski et al. 2002abc, 2003, 2005, Acta Astr.
FLAMES+UVES facilities on the VLT • Field of view 25 arcmin • Multi-fiber link • to UVES spectrograph • (7 targets + 1 Tho) • R ~ 45’000 = 480 – 680 nm • 45 mn on mv=17 • S/N ~ 8 ~30 m/s (The fiber eliminates ~100m/s centering uncertainty in slit)
Doppler follow-up with UVES+FLAMES 2 x 4 nights on VLT 60 best targets followed using multi-fiber and strategy of real-time fiber reallocation
5 transiting hot Jupiters from the OGLE survey OGLE-TR-56 P=1.2 days Konacki et al. 2003 OGLE-TR-10 P=3.1 days Bouchy et al. 2005, Konacki et al. 2005 OGLE-TR-111 P=4.0 days Pont et al. 2004 OGLE-TR-113 P=1.43 days Bouchy et al. 2004, Konacki et al. 2004 OGLE-TR-132 P=1.69 days Bouchy et al. 2004, Moutou et al. 2004
Stellar transits and eclipses Various configurations of eclipsing binaries can mimic a planetary transit signal grazing eclipses small M-dwarf transits triple/quadruple systems Light curves (Udalski et al. 2002) Velocity curves (Bouchy et al. 2005, Pont et al. 2005)
M dwarfs Transiting hot Jupiters Planet-sized brown-dwarf edge The mass-radius relation from stars to planets
HST SMALL TELESCOPES OGLE Spectroscopic follow-up of transit surveys
The example of OGLE-TR-122b A planet-sized M dwarf M = 96 MJR= 1.2 RJP=7.4 daysgravitational modulation nnn mmaganti-transit photometric signalundistinguishable fromplanetary transit !
Conclusions Spectroscopic follow-up is essential to determine the nature of transiting candidates Possible up to V=18 with FLAMES on the VLT Most candidates are eclipsing binaries (numerous confusion scenarios) Medium-deep surveys offer optimal combination of target density and spectroscopic capabilities
OGLE-TR-113b 0.5 MJ HD209458b 0.5 MJ Saturn 0.3 MJ OGLE-TR-123b 70 MJ OGLE-TR-122b 90 MJ
OGLE-TR-113 0.5 MJ HD209458b 0.5 MJ Saturn 0.3 MJ OGLE-TR-123b 70 MJ OGLE-TR-122b 90 MJ