STScI May Symposium 2005 - Baltimore

Frédéric Pont (Geneva)

Francois Bouchy (Marseille), Claudio Melo (ESO), Nuno Santos (Lisbon),

Didier Queloz, Stephane Udry, Michel Mayor (Geneva)

Spectroscopic follow-up of transiting exoplanet surveys

FLAMES follow-up of OGLE III

STScI May Symposium 2005 - Baltimore

7 known transiting exoplanets

10

HD 209458TrES-1OGLE-TR-10OGLE-TR-56OGLE-TR-111OGLE-TR-113OGLE-TR-132

mass-radius relation for hot gas giants

STScI May Symposium 2005 - Baltimore

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 daysV : 15-18 mag : 5-15 mmag

spectroscopic follow-up requireslarge telescope and <100 m/s accuracy

Udalski et al. 2002abc, 2003, 2005, Acta Astr.

STScI May Symposium 2005 - Baltimore

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=17S/N ~ 8 ~30 m/s

(The fiber eliminates ~100m/s centering uncertainty in slit)

FLAMES+UVES facilities on the VLT

STScI May Symposium 2005 - Baltimore

Doppler follow-up with UVES+FLAMES

2 x 4 nights on VLT

60 best targets followed

using multi-fiber andstrategy of real-time fiber reallocation

STScI May Symposium 2005 - Baltimore

5 transiting hot Jupiters from the OGLE survey

OGLE-TR-56 P=1.2 daysKonacki et al. 2003

OGLE-TR-10 P=3.1 daysBouchy et al. 2005, Konacki et al. 2005

OGLE-TR-111 P=4.0 daysPont et al. 2004

OGLE-TR-113 P=1.43 daysBouchy et al. 2004, Konacki et al. 2004

OGLE-TR-132 P=1.69 daysBouchy et al. 2004, Moutou et al. 2004

STScI May Symposium 2005 - Baltimore

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)

STScI May Symposium 2005 - Baltimore

The mass-radius relation from stars to planets

Transiting hot Jupiters Planet-sized

brown-dwarf edge

M dwarfs

STScI May Symposium 2005 - Baltimore

Spectroscopic follow-up of transit surveys

SMALL TELESCOPES OGLEHST

STScI May Symposium 2005 - Baltimore

The example of OGLE-TR-122b

A planet-sized M dwarf

M = 96 MJR= 1.2 RJP=7.4 days

gravitational modulation nnn mmag

anti-transit

photometric signalundistinguishable fromplanetary transit !

STScI May Symposium 2005 - Baltimore

• 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

Conclusions

STScI May Symposium 2005 - Baltimore

OGLE-TR-123b 70 MJ OGLE-TR-122b 90 MJ

HD209458b 0.5 MJOGLE-TR-113b 0.5 MJ Saturn 0.3 MJ

STScI May Symposium 2005 - Baltimore

OGLE-TR-122b 90 MJ

HD209458b 0.5 MJOGLE-TR-113 0.5 MJ Saturn 0.3 MJ

OGLE-TR-123b 70 MJ