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Extrasolar Planetary Transits : Light Curves & Timing Variations. Sergio Hoyer Miranda Departamento de Astronom ía Universidad de Chile. Outline. Introduction Ogle Candidates : OGLE-TR-182 OGLE-TR-131 OGLE-TR-109 Transit Timing Variations (TTV): OGLE-TR-111b
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Extrasolar PlanetaryTransits:Light Curves & TimingVariations Sergio Hoyer Miranda Departamento de Astronomía Universidad de Chile SOCHIAS Santiago, January - 09.
Outline • Introduction • OgleCandidates: OGLE-TR-182 OGLE-TR-131 OGLE-TR-109 • TransitTimingVariations (TTV): OGLE-TR-111b OngoingSurvey SOCHIAS Santiago, January 09
Introduction • 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 SOCHIAS Santiago, January 09
OGLE-TR-182 Data: GMOS - GEMINI South i ‘ & g’ band i-band depth consistent with a Neptune-sized Transiting planet. SOCHIAS Santiago, January 09
OGLE-TR-182 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) SOCHIAS Santiago, January 09
OGLE-TR-131 i band Light Curve SOCHIAS Santiago, January 09
OGLE-TR-131 Using colors and low resolution spectra we conclude is a K2III SOCHIAS Santiago, January 09
OGLE-TR-109 Another candidate: Host Star: F0V Rstar = 1.5 Rsun fast rotating Preliminary Results: Rplanet = 1.3 Rjup Inclination = 76 degrees Period = 0.589 days SOCHIAS Santiago, January 09
Transit Timing Variations • 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 SOCHIAS Santiago, January 09
Transit Timing Variations: OGLE-TR-111b • Possible origin of the variations: • Exomoon ? • Earth-mass planet perturbing the transiting planet ? Winn et al. 07 Minniti et al. 2007 Our work (Kipping, D. M. MNRAS 2009). Diaz, R. et al. 2008 SOCHIAS Santiago, January 09
Transit Timing Variations: OGLE-TR-111b V-band Light Curve of OGLE-TR-111b 3 transits were observed with FORS1 -2 in VLT SOCHIAS Santiago, January 09
Transit Timing Variations 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. SOCHIAS Santiago, January 09