论文标题
一对横跨半径谷的苔丝行星附近的中间矮人矮人有限公司3780
A pair of TESS planets spanning the radius valley around the nearby mid-M dwarf LTT 3780
论文作者
论文摘要
我们介绍了两个新行星的确认，这些新行星在附近的中间矮人LTT 3780（TIC 36724087，TOI-732，$ 732，$ v = 13.07 $，$ k_s = 8.204 $，$ r_s $ = 0.374 r $ $ $ $ __ {\ odot} $ _ {\ odot} $，$ m_s $ __ $ = 0.401M}在单个苔丝部门中鉴定了两个行星候选物，并通过侦察光谱，地面光度随访和高分辨率成像进行了验证。符合测量的轨道周期为$ p_b = 0.77 $ days，$ p_c = 12.25 $ days $ r_ {p，b} = 1.33 = 1.33 \ pm 0.07 $ r $ _ {\ oplus} $，$ r_ {p，c}在低质量恒星周围的时期拉迪乌斯空间，因此该系统是在该恒星质量制度中测试Radius Valley出现的竞争理论的实验室。通过将63个精确的径向速度测量结合在HARP和HARPS-N中，我们测量行星质量为$ M_ {P，B} = 2.62^{+0.48} _ { - 0.46} $ M $ _ {\ oplus} $ {\ oplus} $和$ m_ { m $ _ {\ oplus} $，这表明LTT 3780B具有与地球状的散装组成，而LTT 3780C可能携带了扩展的H/HE信封。我们表明，回收的行星质量与光蒸发和核心驱动质量损失模型的预测一致。 LTT 3780的亮度和小尺寸以及测量的行星参数，使LTT 3780B和C作为可访问的目标，用于在同一行星系统内行星的大气表征并跨越半径谷。
We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, $V=13.07$, $K_s=8.204$, $R_s$=0.374 R$_{\odot}$, $M_s$=0.401 M$_{\odot}$, d=22 pc). The two planet candidates are identified in a single TESS sector and are validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of $P_b=0.77$ days, $P_c=12.25$ days and sizes $r_{p,b}=1.33\pm 0.07$ R$_{\oplus}$, $r_{p,c}=2.30\pm 0.16$ R$_{\oplus}$, the two planets span the radius valley in period-radius space around low mass stars thus making the system a laboratory to test competing theories of the emergence of the radius valley in that stellar mass regime. By combining 63 precise radial-velocity measurements from HARPS and HARPS-N, we measure planet masses of $m_{p,b}=2.62^{+0.48}_{-0.46}$ M$_{\oplus}$ and $m_{p,c}=8.6^{+1.6}_{-1.3}$ M$_{\oplus}$, which indicates that LTT 3780b has a bulk composition consistent with being Earth-like, while LTT 3780c likely hosts an extended H/He envelope. We show that the recovered planetary masses are consistent with predictions from both photoevaporation and from core-powered mass loss models. The brightness and small size of LTT 3780, along with the measured planetary parameters, render LTT 3780b and c as accessible targets for atmospheric characterization of planets within the same planetary system and spanning the radius valley.
