论文标题
TOI-257B（HD 19916b）：温暖的子卫星绕着进化的F型星绕
TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star
论文作者
论文摘要
我们根据NASA的传输系外行星调查卫星（TESS）的数据，报告了温暖的亚塔尔TOI-257B（HD 19916b）的发现。 TESS检测到过境信号，并根据径向速度观测结果确认为行星起源。苔丝光度法，密涅瓦 - 澳大利亚，Feros和Harps径向速度的分析以及恒星振荡的星形震态数据表明，TOI-257B的质量为$ _P = 0.138 \ pm0.023 $ \，$ \ rm，$ \ rm，$ \ rm，$ \ rm \ rm {m_j} $ {m_j} $ {m_j} $ {m_j} $ {m_j} $ {m_p \ rm {m_p \ rm {m_p \ rm {m_p \ rm {m_p \ rm {m_p \ rm {m_p {m_p {m_p = 0.138 \ pm0.023美元（$ 43.9 \ pm7.3 $ \，$ m _ {\ rm \ oplus} $），半径$ r_p = 0.639 \ pm0.013 $ \，$ \ rm \ r_j {r_j} $（$ 7.16 \ pm0.15 $ \，$ r \，$ R _ $ 0.65^{+0.12} _ { - 0.11} $（CGS）和周期$ 18.38818^{+0.00085} _ { - 0.00084} $ \，$ \ rm {days} $。 toi-257b轨道明亮（$ \ mathrm {v} = 7.612 $ \，mag）有些演变为后期的f型星，$ m _*= 1.390 \ pm0.046 $ \，$ \ rm {m _ {m _ {\ odot}} $，$ \ rm { $ r _*= 1.888 \ pM0.033 $ \，$ \ rm {r _ {\ odot}} $，$ t _ {\ rm eff} = 6075 \ pm90 $ \，$ \ rm {k rm {k} $ $ v \ sin {i} = 11.3 \ pm0.5 $ \，km \，s $^{ - 1} $。此外，我们发现使用径向速度数据的$ \ sim71 $ \ $ \ sim71 $ \上的第二个非传输子质量质量行星的提示。该系统加入了少数用星号学特征的系外行星宿主星（$ \ sim100 $）的等级。在已知的系外行星样本中，温暖的亚腾星很少见，因此，在研究类似行星系统的形成和迁移历史的情况下，TOI-257b的发现很重要。
We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the Minerva-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of $M_P=0.138\pm0.023$\,$\rm{M_J}$ ($43.9\pm7.3$\,$M_{\rm \oplus}$), a radius of $R_P=0.639\pm0.013$\,$\rm{R_J}$ ($7.16\pm0.15$\,$R_{\rm \oplus}$), bulk density of $0.65^{+0.12}_{-0.11}$ (cgs), and period $18.38818^{+0.00085}_{-0.00084}$\,$\rm{days}$. TOI-257b orbits a bright ($\mathrm{V}=7.612$\,mag) somewhat evolved late F-type star with $M_*=1.390\pm0.046$\,$\rm{M_{\odot}}$, $R_*=1.888\pm0.033$\,$\rm{R_{\odot}}$, $T_{\rm eff}=6075\pm90$\,$\rm{K}$, and $v\sin{i}=11.3\pm0.5$\,km\,s$^{-1}$. Additionally, we find hints for a second non-transiting sub-Saturn mass planet on a $\sim71$\,day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars ($\sim100$) that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems.
