SOCHIAS Santiago, January Sergio Hoyer Miranda Departamento de Astronomía Universidad de Chile 1

 Introduction  Ogle Candidates: OGLE-TR-182 OGLE-TR-131 OGLE-TR-109  Transit Timing Variations (TTV): OGLE-TR-111b Ongoing Survey SOCHIAS Santiago, January 09 Outline

Introduction SOCHIAS Santiago, January 09 Exoplanetary Transits:  55 Transiting Planets has been detected.*  False Positives: - Statistics (photometric noise) - Instrumentals (errors in the photometry) - Astrophisycs ( binary or multiple systems )  Parameters we can infer: Planet Radius, Orbital Period Orbit Inclination Tc,Td (with RV’s)  Planet DENSITY

OGLE-TR SOCHIAS Santiago, January 09 Data: GMOS - GEMINI South i ‘ & g’ band i-band depth consistent with a Neptune-sized Transiting planet.

OGLE-TR SOCHIAS Santiago, January 09 Data: GMOS - GEMINI South i ‘ & g’ band i-band depth consistent with a Neptune-sized Transiting planet. but….. Eclipsing binary blended with a background reddened GIANT (Hoyer et al. 2007)

OGLE-TR SOCHIAS Santiago, January 09 i band Light Curve

OGLE-TR SOCHIAS Santiago, January 09 Using colors and low resolution spectra we conclude is a K2III

OGLE-TR SOCHIAS Santiago, January 09 Another candidate: Host Star: F0V R star = 1.5 R sun fast rotating Preliminary Results: R planet = 1.3 R jup Inclination = 76 degrees Period = days

Transit Timing Variations SOCHIAS Santiago, January 09 In general Transit Detection is biased towards Giants Exoplanets. The smallest Transiting Planet detected until now is a Neptune-sized (HAT-P-11b). TTVs: short term variations in Tc due gravitational interaction of the transiting planet with an unseen companion. TTVs could potentially detect down to Earth-mass planets from ground based telescopes. Also long term variations of Tc can be produce by the presence of another planet in the system (orbital precession) *exoplanet.eu

Transit Timing Variations: OGLE-TR- 111b SOCHIAS Santiago, January 09 Possible origin of the variations: Exomoon ? Earth-mass planet perturbing the transiting planet ? Diaz, R. et al Winn et al. 07 Minniti et al Our work (Kipping, D. M. MNRAS 2009).

Transit Timing Variations: OGLE-TR- 111 b SOCHIAS Santiago, January 09 3 transits were observed with FORS1 -2 in VLT V-band Light Curve of OGLE-TR-111b

Transit Timing Variations SOCHIAS Santiago, January 09 We are currently performing a search for unseen companions of transiting planets using TTV’s. Recently obtained data from GEMINI Observatory, SOAR Telescope and CTIO 1 mt Telescope. Working in a code to do Deconvolution Photometry. Is also important to monitoring long term variations of the central Time of Transits.