NGTS-5b: a highly inflated planet offering insights into the sub-Jovian desert
NGTS-5b: a highly inflated planet offering insights into the sub-Jovian desert
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DOI：
10.1051/0004-6361/201935206
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发表时间：
2019-05
影响因子：
6.5
通讯作者：
P. Eigmüller;A. Chaushev;E. Gillen;Alexis M. S. Smith;L. Nielsen;O. Turner;S. Csizmadia;B. Smalley-B.
中科院分区：
文献类型：
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作者：
P. Eigmüller;A. Chaushev;E. Gillen;Alexis M. S. Smith;L. Nielsen;O. Turner;S. Csizmadia;B. Smalley-B.
上下文行星人口分析使我们能够深入了解形成和演化过程。对于短周期行星，亚木星沙漠近年来一直在讨论关于行星人口的质量/周期和半径/周期参数空间，而不考虑恒星参数。下一代凌日巡天（NGTS）被优化用于探测这一区域的行星，这使得对亚木星沙漠的进一步分析成为可能。目标。对于高精度的光度测量（例如NGTS和TESS），其目的是探测短周期行星，特别是M/K型主星周围的行星，当经验数据与模型预测进行比较时，需要考虑恒星参数。介绍了一个新发现的行星在亚木星沙漠的边界，我们分析了它的体积属性，并用它来显示边界的亚木星沙漠系外行星的属性。方法.利用NGTS光变曲线和光谱跟踪观测，我们确认了行星NGTS-5 b的行星性质，并确定了它的质量。利用系外行星档案，我们将这颗行星与其他发现联系起来。结果NGTS-5 b是一颗短周期行星，轨道周期为3.3569866 ± 0.0000026天。质量为0.229 ± 0.037 MJup，半径为1.136 ± 0.023 RJup，高度膨胀。它的质量使它位于亚木星沙漠的上边界。由于宿主是一颗K2矮星，因此在分析NGTS-5 b的行星种群时，我们需要考虑恒星参数。结论.通过红敏感的调查（例如NGTS和TESS），我们预计会发现更多的晚型恒星周围的行星。因此，对亚木星沙漠的经验分析应该考虑恒星参数。
Context. Planetary population analysis gives us insight into formation and evolution processes. For short-period planets, the sub-Jovian desert has been discussed in recent years with regard to the planet population in the mass/period and radius/period parameter space without taking stellar parameters into account. The Next Generation Transit Survey (NGTS) is optimised for detecting planets in this regime, which allows for further analysis of the sub-Jovian desert. Aims. With high-precision photometric surveys (e.g. with NGTS and TESS), which aim to detect short period planets especially around M/K-type host stars, stellar parameters need to be accounted for when empirical data are compared to model predictions. Presenting a newly discovered planet at the boundary of the sub-Jovian desert, we analyse its bulk properties and use it to show the properties of exoplanets that border the sub-Jovian desert. Methods. Using NGTS light curve and spectroscopic follow-up observations, we confirm the planetary nature of planet NGTS-5b and determine its mass. Using exoplanet archives, we set the planet in context with other discoveries. Results. NGTS-5b is a short-period planet with an orbital period of 3.3569866 ± 0.0000026 days. With a mass of 0.229 ± 0.037 MJup and a radius of 1.136 ± 0.023 RJup, it is highly inflated. Its mass places it at the upper boundary of the sub-Jovian desert. Because the host is a K2 dwarf, we need to account for the stellar parameters when NGTS-5b is analysed with regard to planet populations. Conclusions. With red-sensitive surveys (e.g. with NGTS and TESS), we expect many more planets around late-type stars to be detected. An empirical analysis of the sub-Jovian desert should therefore take stellar parameters into account.