TITRESearch and Characterization of Extrasolar planets

in Antartica

François BouchyInstitut d’Astrophysique de Paris

Status : ~ 200 known extrasolar planets

Earth

Jup

Sat

10 transiting extrasolar planetsCharacterized by photometry and radial velocity

VHJ

10 transiting extrasolar planetsCharacterized by photometry and radial velocity

VHJ

Photometry + Radial Velocity + Spectroscopy Fully complementary methods

a, P, e, T0, b,

mp, rp, , mcore , T, evap. , …

R*, M*, [Fe/H], vsini, R’HK , …

Constraints for processes of formation and evolution Constraints for composition and internal structure

--- 0--- 0--- 0--- 0--- 1--- 0--- 0--- 0--- 0--- 0--- 0--- 0--- 0--- 0--- 0--- 0--- 0--- 5--- 0--- 0--- 0--- 0--- 0--- 6

Lack of efficiency of photometric surveys

More than 200 planets per month were expected

Up to day a total of only 7 detections

1st main limitation : time coverage

Most abundant Hot Jupiters [3-4 d]

Tres-1 [3.03 d]OGLE-10b [3.10 d]

Xo-1 [3.94 d]OGLE-111b [4.02 d]

OGLE-56b [1.21 d]OGLE-113b [1.43 d]OGLE-132b [1.69 d]

Need of continuous coverage

60-day continuous coverage (Antarctica)

60-day nighttime coverage (OGLE)

Period [days]

2nd main limitation : systematic errors

HD209458OGLE-TR-10OGLE-TR-132

1%

Tres-1

Transit Depth

OGLE-113 2.9% Tres-1 2.3%Xo-1 2.0%OGLE-111 1.9%OGLE-10 1.9%OGLE-56 1.3 %OGLE-132 1.1 %

No transiting planet detected with a depth < 1.1%

mmag precision is possible from ground

OGLE-113 with SUSI/NTTOGLE-132 with FORS/VLT

HD149036

Gillon et al. submitted

Sato et al. (2005)

Moutou et al. (2004)

systematic errors due to the atmosphere are expected to be considerably reduced ….

Need of stable atmospheric conditions

… but not systematic errors due to the instrument !

- intra pixel response- Flat field stability - ….

Main Scientific goals of photometric survey for transiting planets

Increase the number of transiting Hot Jupiters

especially around bright stars for complementary and further observations

Main Scientific goals of photometric survey for transiting planets

Detect and characterizetransiting Hot Neptunes

Sub mmag clearly required

Main Scientific goals of photometric survey for transiting planets

Detect and characterizetransiting big Earth in the habitable zone of M-K dwarfs

Several seasons on the same fields

Mass-radius relation from planets to BDs and to low mass stars

Galactic plane visible from Dome C during 3 month with secz < 2.

Doppler follow is required

- to discriminate confusing case- to assess the planetary nature of the transit- to determine the mass of the planet

ESO Facilities for South hemisphere already used for follow-up(GIRAFFE / FLAMES-UVES / HARPS)

But limited to mv < 15.5

Secondary objectives of photometric survey :

- Stellar pulsation - Stellar activity- Eclipsing binaries - ….

Conclusions

• Continuous time coverage is crucial to exoplanet transit survey.

• Better photometric conditions also allow to reach the planetary transit realm.

Transit survey in Dome C + Doppler follow-up

huge contribution to the knowledge of exoplanets