论文标题
苔丝向已知的长期巨型行星揭示了一个短周期的子纽布兄弟姐妹(HD 86226C)
TESS Reveals a Short-period Sub-Neptune Sibling (HD 86226c) to a Known Long-period Giant Planet
论文作者
论文摘要
过境系外行星调查卫星任务旨在在附近明亮的恒星周围找到过境行星。在这里,我们介绍了一个小的,短周期的检测和质量测量($ \ of \,4 $ \,天数)过渡行星,周围是明亮的($ v = 7.9 $),太阳能星HD 86226(TOI-652,TOI-652,TIC 22221375),以前众所周知,以前众所周知,可以主持一个长期planse oper to Borness op tote the Roneperperiod($ 1600)。 HD 86226C(TOI-652.01)的半径为$ 2.16 \ pm0.08 $ $ $ $ $ r _ {\ oplus} $,质量为7.25 $^{+1.19} _ { - 1.12} $ $ m _ {$ m _ {\ oplus} $基于档案和新的radial velocity。我们还更新了较长的周期,未知的横向行星的参数,发现它比以前报道的不那么偏心和较大。过境星球的密度为$ 3.97 $ g cm $^{ - 3} $,它足够低,表明该星球至少具有较小的挥发性信封,但是岩石,铁和水的质量分数尚未得到很好的约束。鉴于寄主之星的亮度,行星时期和地球的位置在``半径差距''和``热海王星沙漠''附近,HD 86226C是传输光谱的有趣候选者,可以进一步完善其组成。
The Transiting Exoplanet Survey Satellite mission was designed to find transiting planets around bright, nearby stars. Here we present the detection and mass measurement of a small, short-period ($\approx\,4$\,days) transiting planet around the bright ($V=7.9$), solar-type star HD 86226 (TOI-652, TIC 22221375), previously known to host a long-period ($\sim$1600 days) giant planet. HD 86226c (TOI-652.01) has a radius of $2.16\pm0.08$ $R_{\oplus}$ and a mass of 7.25$^{+1.19}_{-1.12}$ $M_{\oplus}$ based on archival and new radial velocity data. We also update the parameters of the longer-period, not-known-to-transit planet, and find it to be less eccentric and less massive than previously reported. The density of the transiting planet is $3.97$ g cm$^{-3}$, which is low enough to suggest that the planet has at least a small volatile envelope, but the mass fractions of rock, iron, and water are not well-constrained. Given the host star brightness, planet period, and location of the planet near both the ``radius gap'' and the ``hot Neptune desert'', HD 86226c is an interesting candidate for transmission spectroscopy to further refine its composition.