View
213
Download
0
Tags:
Embed Size (px)
Citation preview
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