Magnetic Activity and Physical Parameters of Exoplanet Host Stars Based on LAMOST DR7, TESS, Kepler, and K2 Surveys
Magnetic Activity and Physical Parameters of Exoplanet Host Stars Based on LAMOST DR7, TESS, Kepler, and K2 Surveys
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DOI：
10.3847/1538-4365/ac7151
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发表时间：
2022-07
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通讯作者：
Tianhao Su;Li-yun Zhang;L. Long;Xianming L. Han;P. Misra;G. Meng;Q. Pi;Zilu Yang;Jiawei Yang
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作者：
Tianhao Su;Li-yun Zhang;L. Long;Xianming L. Han;P. Misra;G. Meng;Q. Pi;Zilu Yang;Jiawei Yang
大天区多目标光纤光谱望远镜（LAMOST）的中低分辨率光谱测量对于确定太阳系外行星系统的轨道参数和色球活动非常重要。我们将2021年3月11日之前确认的系外行星目录与LAMOST DR7调查进行交叉匹配，以研究它们的性质。在LAMOST DR7低分辨率光谱巡天中观测到1026个有系外行星的目标，在中分辨率光谱巡天中观测到158个目标。计算了Hα线的等效宽度，确定了它们的恒星活动性。当Rossby数Ro ≤ 0.12时，Hα和耀斑强度在饱和区几乎不变，而在非饱和区随Ro的增大而减小。此外，我们在凌日系外行星调查卫星（TESS），开普勒和K2调查中搜索了所有具有系外行星的恒星的耀斑事件。在TESS观测的733个太阳系外行星系统中，我们发现了来自57颗恒星的481个耀斑。对于开普勒数据，我们获得了1699颗恒星的光变曲线，发现了417颗恒星的1886个耀斑。对于K2数据，我们获得了347颗恒星的光变曲线，发现了89颗恒星的467个耀斑。TESS巡天观测到361个有明显食分的天体有光变曲线。我们使用JKTEBOP程序以高信噪比拟合了它们的光变曲线，并重新获得了轨道参数，如倾角，半径和周期。最后，我们对有耀斑恒星系外行星的可居住性做出了判断。
Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) low- and medium-resolution spectroscopic surveys are important for determination of the orbital parameters and chromospheric activity of extrasolar planet systems. We crossmatched the exoplanet catalog confirmed before 2021 March 11 with the LAMOST DR7 survey to study their properties. There are 1026 targets with exoplanets observed in the LAMOST DR7 low-resolution spectroscopic survey and 158 targets in the medium-resolution spectroscopic survey. We have calculated the equivalent width of the Hα line and determined their stellar activity. The Hα and flare intensities are almost constant for the Rossby number Ro ≤ 0.12 in the saturated regime and decrease with increasing Ro in the unsaturated regime. In addition, we searched the flare events of all stars with exoplanets in the Transiting Exoplanet Survey Satellite (TESS), Kepler, and K2 surveys. Among the 733 extrasolar planetary systems observed by TESS, we found 481 flares from 57 stars. For Kepler data, we obtained the light curve of 1699 stars and found 1886 flares from 417 stars. For K2 data, we obtained the light curves of 347 stars and found 467 flares from 89 stars. There were light curves of 361 objects with obvious eclipse observed from the TESS survey. We have fitted their light curves with a high signal-to-noise ratio using the JKTEBOP program, and we reobtained the orbital parameters, such as inclination, radius, and period. In the end, we made a judgment on the habitability of exoplanets of stars with flares.