Hints of Period Change for OGLE-TR-113b
Abstract
We present six new transits of the hot Jupiter OGLE-TR-113b observed with MagIC on the Magellan Telescopes between January 2007 and May 2009. We update the system parameters and revise the planetary radius, where the error is dominated by stellar radius uncertainties. The new transit midtimes reveal no transit timing variations from a constant ephemeris over two years, which places an upper limit of 1-2 Earth masses on any perturber in a 1:2 or 2:1 mean-motion resonance with OGLE-TR-113b. Combining the new transit epochs with five epochs published between 2002 and 2006, we find hints that the orbital period of the planet may not be constant, with the best fit indicating the period is decreasing by 60±15 milliseconds per year. If real, this change in period could result from either a long-period (more than 8 years) timing variation due to an external perturber, or more intriguingly from the orbital decay of the planet. The detection of a changing period is still tentative and must be checked with additional observations. If a period decay is confirmed, OGLE-TR-113b will be the first planet observed to be falling onto its star. This would enable direct tests of tidal stability and dynamical models of close-in planets and place observational constraints on the value of stellar tidal energy dissipation factors.
This work was supported in part by NASA Origins grant NNX07AN63G and Hubble Fellowship grant HF-01210.01-A/HF-51233.01 awarded by the STScI, which is operated by the AURA, Inc. for NASA, under contract NAS5-26555.- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #42
- Pub Date:
- October 2010
- Bibcode:
- 2010DPS....42.6202A