标题： OGLE-TR-111b的轨道周期变化缺失：对六个新观测时刻的重新分析 显示英文标题

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

摘要： 我们展示了在2008年4月至2009年3月期间使用智利的麦哲伦望远镜观测到的六次新的系外行星OGLE-TR-111b的凌日事件。我们将这些新的凌日事件与该行星在2005年至2006年间之前发表的五个凌日时刻结合，以扩展对该系统凌日时间变化的分析。我们得出一个新的行星半径值为1.019 +/- 0.026 R_J，介于之前报告的1.067 +/- 0.054 R_J（Winn等，2007）和0.922 +/- 0.057 R_J（Diaz等，2008）之间。我们还检查了Diaz等（2008）关于凌日时间变化和持续时间变化的声明。我们对所有十一个凌日时刻的分析没有发现任何偏差超过2 sigma的点，大多数点都在1 sigma以内。尽管凌日持续时间在四年数据跨度内名义上有所减少，但光度测量中的系统误差可以解释这一结果。因此，该系统中没有令人信服的证据表明存在时间或持续时间的变化。数值积分将与OGLE-TR-111b处于2:1平均运动共振中的潜在第二颗行星的质量上限设定为约1 M_E。 显示英文摘要

摘要： 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.