LACK OF TRANSIT TIMING VARIATIONS OF OGLE-TR-111b: A RE-ANALYSIS WITH SIX NEW EPOCHS*

摘要

We present six new transits of the exoplanet OGLE-TR-111b observed with the Magellan Telescopes in Chile between 2008 April and 2009 March. We combine these new transits with five previously published transit epochs for this planet between 2005 and 2006 to extend the analysis of transit timing variations (TTVs) reported for this system. We derive a new planetary radius value of 1.019 ± 0.026 RJ , which is intermediate to the previously reported radii of 1.067 ± 0.054 RJ and 0.922 ± 0.057 RJ . We also examine the TTV and duration change claims of Dìaz et al. Our analysis of all 11 transit epochs does not reveal any points with deviations larger than 2σ, and most points are well within 1σ. Although the transit duration nominally decreases over the four year span of the data, systematic errors in the photometry can account for this result. Therefore, there is no compelling evidence for either a timing or a duration variation in this system. Numerical integrations place an upper limit of about 1 M ⊕ on the mass of a potential second planet in a 2:1 mean-motion resonance with OGLE-TR-111b.