标题： TESS和CARMENES发现围绕Ross 176运行的凌星热水世界候选天体 显示英文标题

标题： Discovery of a transiting hot water-world candidate orbiting Ross 176 with TESS and CARMENES

摘要： 罗斯176的情况是一颗晚期K型恒星，它拥有一颗有希望的海洋世界候选行星。 该恒星的半径为$R_*$=0.569$\pm$0.020$R_{\odot}$，质量为$M_{\star}$ = 0.577 $\pm$ 0.024 $M_{\odot}$。 我们使用来自CARMENES的光谱数据来限制行星质量，该仪器已经在确认TESS检测到的凌日信号的行星性质方面发挥了重要作用。 我们使用高斯过程（GP）来改进分析，因为该恒星具有相对较强的活动性，这会影响径向速度数据集。 此外，我们在TESS光曲线中应用了GP，以减少去趋势数据集中的相关噪声。 恒星活动指标显示了一个与恒星自转周期$\sim$ 32天相关的强信号。 该恒星活动信号也在TESS光曲线中得到了确认。 Ross 176b是一个内层热凌日行星，其轨道偏心率较低，为$e = 0.25 \pm 0.04$，轨道周期为$P \sim 5$天，平衡温度为$T_{eq}\sim 682K$。 半径为$R_p = 1.84\pm0.08R_{\oplus}$（4%精度），质量为$M_p = 4.57^{+0.89}_{-0.93} M_{\oplus}$（20%精度），平均密度为$\rho_p = 4.03^{+0.49}_{-0.81} g cm^{-3}$，Ross 176b的组成可能与水世界情景一致。 此外，Ross 176b是大气特征研究的有希望的目标，这可能会提供更多关于水世界存在、形成和组成的资料。 这一发现增加了围绕K型恒星运行的行星样本。 这个样本对于研究这类恒星周围小半径行星的空隙具有价值。 这项研究还表明，空间和地面望远镜的双重检测对于确认新行星是高效的。 显示英文摘要

摘要： The case of Ross 176 is a late K-type star that hosts a promising water-world candidate planet. The star has a radius of $R_*$=0.569$\pm$0.020$R_{\odot}$ and a mass of $M_{\star}$ = 0.577 $\pm$ 0.024 $M_{\odot}$. We constrained the planetary mass using spectroscopic data from CARMENES, an instrument that has already played a major role in confirming the planetary nature of the transit signal detected by TESS. We used Gaussian Processes (GP) to improve the analysis because the host star has a relatively strong activity that affects the radial velocity dataset. In addition, we applied a GP to the TESS light curves to reduce the correlated noise in the detrended dataset. The stellar activity indicators show a strong signal that is related to the stellar rotation period of $\sim$ 32 days. This stellar activity signal was also confirmed on the TESS light curves. Ross 176b is an inner hot transiting planet with a low-eccentricity orbit of $e = 0.25 \pm 0.04$, an orbital period of $P \sim 5$ days, and an equilibrium temperature of $T_{eq}\sim 682K$. With a radius of $R_p = 1.84\pm0.08R_{\oplus}$ (4% precision), a mass of $M_p = 4.57^{+0.89}_{-0.93} M_{\oplus}$ (20% precision), and a mean density of $\rho_p = 4.03^{+0.49}_{-0.81} g cm^{-3}$, the composition of Ross 176b might be consistent with a water-world scenario. Moreover, Ross 176b is a promising target for atmospheric characterization, which might lead to more information on the existence, formation and composition of water worlds. This detection increases the sample of planets orbiting K-type stars. This sample is valuable for investigating the valley of planets with small radii around this type of star. This study also shows that the dual detection of space- and ground-based telescopes is efficient for confirm new planets.