Properties of binary systems found in the CoRoT exoplanet search J.M. Almenara, H. Deeg, CoRoT Detection WG, CoRoT Ground-Based Follow-Up WG, Planets in binaries WG

Outline Overview of systems found in the exoplanet search Results from Follow-Up observations Some special cases of binary configurations found in the planet detection effort

Sample All detections from IRa01, LRc01 and LRa01 –12 < R [mag] < 16 –0.24 < P [days] < –0.018 < DF/F [%] < –Run durations: IRa01 55 days LRc days LRa days # targets# detections% detections IRa LRa anticenter* center=LRc total * IRa01 and LRa01 have 1402 targets and 30 detections in common

Magnitude distribution (cumulative, normalized to 1)

Magnitude

Period distribution 60 days log N  -2/3 log P

Eclipse depth

0.015% 1.3R E in front of a 1R ⊙ 80 transits → 2 day period for a Long Run

Comparison of predicted ‘alarms’ of all kinds (Brown 2003) with Corot Much less detetections for DF/F = 0.1 – 0.4% than expected from Brown 2003 Reasons: (minor) lacking detc. efficiency for faint/long-periodic objects (major) overestimation by Brown – different sample assumptions

Astronomical Sources of false alarms (adapted from Brown 2003) PLANETS We look for: Eclipsing Binaries in triple system Eclipsing Binaries + unrelated (fg/bg) star within psf DILUTED BINARIES UNDILUTED BINARIES Confusion from: Grazing Eclipsing Binaries Eclipsing Binaries with deep eclipses + light from a bright 3rd star → shallow eclipses Eclipses of stellar components with large mass ratio

Results from Follow-Up Observations (IRa01,LRa01,LRc01) 122 candidates in Follow-Up lists 49 solved by Follow-Up (40 %) #Follow-Up resultIn this analysis# 13SB1 UNDILUTED BINARIES18 5SB2 5BLEND DILUTED BINARIES25 19BEB 1TRIPLE 6PLANETPLANETS6

False alarm rates Brown 2003 –R<12 –20” confusion radius

Some Special cases of binary configurations found in the planet detection effort

Planet candidate + eclipsing binary in the same mask Found by Aviv Ofir Eclipsing binary 1.1 d period Planet candidate 13.5 d period dF/F = 0.9 %

Two objects separated 4”

Original LC LC – Binary (1.772 d) Folded (2.628 d) =SRc01_E2_ binaries in the same mask 7 cases in 5 fields (0.015%)

2 binaries in the same mask Original LC Folded (P=2.46 d) = IRa01_E2_ cases in 5 fields (0.015%)

Semi-periodic? = SRc01_E1_ binaries in the same mask

-> confusion with a second eccentric binary i: red: orig. curve ii: removal of first binary iii: smooth after removal of first binary smooth curve folded by P= d 2 binaries in the same mask