arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1305.3271astro-ph.EP
收藏

开普勒系外行星的光学相位曲线

Optical Phase Curves of Kepler Exoplanets

Lisa J. Esteves, Ernst J. W. De Mooij, Ray Jayawardhana

摘要:

我们已经进行了全面的搜索光学相位变化的所有行星候选人与紧密的轨道在15个季度的数据从开普勒太空望远镜。在对系统学进行校正后,我们发现了八个系统,它们似乎显示了次日食和相位变化。其中五个(Kepler-5,Kepler-6,Kepler-8,KOI-64和KOI-2133)是新的,三个(TrES-2,HAT-P-7和KOI-13)先前已经发表了相位曲线,尽管观测数量要少得多。我们模拟了每个行星候选者的全相位曲线,包括主凌日和次凌日,并推导出它们的太阳黑子、白天和夜晚的温度、椭球变化和多普勒波束。我们发现KOI-64和KOI-2133的夜面温度远高于它们的平衡值(而KOI-2133的夜面温度也大于1),因此我们得出结论,它们很可能是自发光天体,而不是行星。其他六颗候选行星的特征与它们是低几何曲率(<0.3)的行星相一致。对于TrES-2和KOI-13,开普勒带通似乎探测了比行星平衡温度更热的大气层。对于KOI-13,我们检测到一个从未见过的三次余弦谐波,其振幅为6.7+/-0.3 ppm,相位曲线残差中的相移为-1.1+/-0.1弧度,这可能是由于其自旋轨道未对准。我们报告派生行星参数的所有六颗行星,包括质量从椭球的变化和多普勒波束,并比较我们的结果公布的值时可用。我们的研究结果几乎使开普勒系外行星的数量增加了一倍,并测量了相位曲线的变化,从而为近距离热彗星的性质提供了有价值的新约束。

英文摘要:

We have conducted a comprehensive search for optical phase variations of all planet candidates with tight orbits in fifteen quarters of data from the Kepler space telescope. After correcting for systematics, we found eight systems that appear to show secondary eclipses as well as phase variations. Of these, five (Kepler-5, Kepler-6, Kepler-8, KOI-64 and KOI-2133) are new and three (TrES-2, HAT-P-7 and KOI-13) have previously published phase curves, albeit with many fewer observations. We model the full phase curve of each planet candidate, including the primary and secondary transits, and derive their albedos, day- and night-side temperatures, ellipsoidal variations and Doppler beaming. We find that KOI-64 and KOI-2133 have night-side temperatures well above their equilibrium values (while KOI-2133 also has an albedo >1), so we conclude that they are likely to be self-luminous objects rather than planets. The characteristics of the six other candidates are consistent with their being planets with low geometric albedos (<0.3). For TrES-2 and KOI-13, the Kepler bandpass appears to probe atmospheric layers hotter than the planet's equilibrium temperature. For KOI-13, we detect a never-before-seen third cosine harmonic with an amplitude of 6.7+/-0.3 ppm and a phase shift of -1.1+/-0.1 radians in the phase curve residual, which could be due to its spin-orbit misalignment. We report derived planetary parameters for all six planets, including masses from ellipsoidal variations and Doppler beaming, and compare our results to published values when available. Our results nearly double the number of Kepler exoplanets with measured phase curve variations, thus providing valuable new constraints on the properties of close-in hot Jupiters.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑