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 \pm 0.026 ~ { } R _ { J } , which is intermediate to the previously reported radii of 1.067 \pm 0.054 ~ { } R _ { J } ( ) and 0.922 \pm 0.057 ~ { } R _ { J } ( ) .
We also examine the transit timing variation and duration change claims of .
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 _ { \oplus } on the mass of a potential second planet in a 2:1 mean-motion resonance with OGLE-TR-111b .