The GTC exoplanet transit spectroscopy survey III. No asymmetries in the transit of CoRoT-29b
The GTC exoplanet transit spectroscopy survey III. No asymmetries in the transit of CoRoT-29b
复制标题
GTC 系外行星凌日光谱调查 III。
DOI：
10.1051/0004-6361/201527881
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发表时间：
2016
影响因子：
6.5
通讯作者：
Iro N.
中科院分区：
文献类型：
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作者：
Palle E.;Chen G.;Alonso R.;Nowak G.;Deeg H.;Cabrera J.;Murgas F.;Parviainen H.;Nortmann L.;Hoyer S.;Prieto-Arranz J.;Nespral D.;Cabrera Lavers A.;Iro N.
太阳系外行星空间飞行任务的启动从空间获得了精确的测光，导致发现了数千个具有非常不同的物理特性和结构的行星系统。2011年夏季，使命观测到的太阳系外行星CoRoT-29 b的凌日光变曲线呈现出不对称性，并通过重力暗化效应对其进行了初步解释，目的是利用精密测光技术对CoRoT-29 b的凌日进行测量，以表征其凌日形状的不对称性。我们进行分光光度差分观测，这使我们能够计算出高精度的光度光变曲线，并研究了过境的颜色依赖性。ResultsAfter仔细的数据分析，我们发现，以前报道的不对称性不存在于任何两个过境，在2014年7月和2015年7月观察到的高光度精度为300 ppm超过5分钟。由于星星的相对暗淡，我们没有达到执行其大气透射光谱所需的精度，但我们没有看到颜色依赖的过境深度或daily.ConclusionsWe的结论是，以前报道的不对称性可能是一个时间依赖性的现象，这并没有发生在最近的时代。或者，发现数据中的工具效应可能需要重新考虑。
ContextThe launch of the exoplanet space missions obtaining exquisite photometry from space has resulted in the discovery of thousands of planetary systems with very different physical properties and architectures. Among them, the exoplanet CoRoT-29b was identified in the light curves the mission obtained in summer 2011, and presented an asymmetric transit light curve, which was tentatively explained via the effects of gravity darkening.AimsTransits of CoRoT-29b are measured with precision photometry, to characterize the reported asymmetry in their transit shape.MethodsUsing the OSIRIS spectrograph at the 10-m GTC telescope, we perform spectro-photometric differential observations, which allow us to both calculate a high-accuracy photometric light curve, and a study of the color-dependence of the transit.ResultsAfter careful data analysis, we find that the previously reported asymmetry is not present in either of two transits, observed in July 2014 and July 2015 with high photometric precisions of 300 ppm over 5 min. Due to the relative faintness of the star, we do not reach the precision necessary to perform transmission spectroscopy of its atmosphere, but we see no signs of color-dependency of the transit depth or duration.ConclusionsWe conclude that the previously reported asymmetry may have been a time-dependent phenomenon, which did not occur in more recent epochs. Alternatively, instrumental effects in the discovery data may need to be reconsidered.