Lack of Transit Timing Variations of OGLE-TR-111b: A re-analysis with six new epochs

TL;DR

This study re-analyzed transit data of OGLE-TR-111b with six new observations, finding no significant transit timing or duration variations, and placed constraints on potential additional planets in the system.

Contribution

It provides an updated analysis of transit timing variations with new data, refutes previous claims of variations, and constrains the mass of possible second planets.

Findings

No significant transit timing deviations detected.

Transit duration remains consistent within errors.

Upper mass limit of ~1 Earth mass for a second planet in resonance.

Abstract

We present six new transits of the exoplanet OGLE-TR-111b observed with the Magellan Telescopes in Chile between April 2008 and March 2009. 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 reported for this system. We derive a new planetary radius value of 1.019 +/- 0.026 R_J, which is intermediate to the previously reported radii of 1.067 +/- 0.054 R_J (Winn et al. 2007) and 0.922 +/- 0.057 R_J (Diaz et al. 2008). We also examine the transit timing variation and duration change claims of Diaz et al. (2008). Our analysis of all eleven transit epochs does not reveal any points with deviations larger than 2 sigma, and most points are well within 1 sigma. 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_E on the mass of a potential second planet in a 2:1 mean-motion resonance with OGLE-TR-111b.