An Earth-sized Planet around an M5 Dwarf Star at 22 pc
An Earth-sized Planet around an M5 Dwarf Star at 22 pc
复制标题
DOI：
10.3847/1538-3881/acb7e1
复制
发表时间：
2023-02
期刊：
影响因子：
--
通讯作者：
T. Hirano;F. Dai;J. Livingston;S. Grziwa;K. Lam;Yui Kasagi;N. Narita;H. Ishikawa;K. Miyakawa;L. Serrano;Yuji Matsumoto;E. Kokubo;T. Kimura;M. Ikoma;J. Winn;J. Wisniewski;H. Harakawa;H. Teng;W. Cochran;A. Fukui;Davide Gandolfi;E. Guenther;Y. Hori;K. Ikuta;K. Kawauchi;E. Knudstrup;J. Korth;T. Kotani;V. Krishnamurthy;T. Kudo;T. Kurokawa;M. Kuzuhara;R. Luque;M. Mori;J. Nishikawa;M. Omiya;J. Orell-Miquel;E. Pallé;C. M. Persson;S. Redfield;E. Serabyn;Alexis M. S. Smith;A. Takahashi;T. Takarada;A. Ueda;V. Van Eylen;S. Vievard;Motohide Tamura;B. Sato
中科院分区：
文献类型：
--
作者：
T. Hirano;F. Dai;J. Livingston;S. Grziwa;K. Lam;Yui Kasagi;N. Narita;H. Ishikawa;K. Miyakawa;L. Serrano;Yuji Matsumoto;E. Kokubo;T. Kimura;M. Ikoma;J. Winn;J. Wisniewski;H. Harakawa;H. Teng;W. Cochran;A. Fukui;Davide Gandolfi;E. Guenther;Y. Hori;K. Ikuta;K. Kawauchi;E. Knudstrup;J. Korth;T. Kotani;V. Krishnamurthy;T. Kudo;T. Kurokawa;M. Kuzuhara;R. Luque;M. Mori;J. Nishikawa;M. Omiya;J. Orell-Miquel;E. Pallé;C. M. Persson;S. Redfield;E. Serabyn;Alexis M. S. Smith;A. Takahashi;T. Takarada;A. Ueda;V. Van Eylen;S. Vievard;Motohide Tamura;B. Sato
我们报告在围绕 K2-415（EPIC 211414619）（一颗 22 颗 M5V 恒星）的 P = 4.02 天轨道上发现了一颗地球大小的凌日行星 (R p = 1.015 ± 0.051 R ⊕)。这颗候选行星首先是通过分析 K2 任务获得的光曲线数据来识别的，这里显示它存在于 TESS 的最新数据中。将光变曲线与我们后续观察获得的数据（包括高分辨率成像和 IRD 近红外光谱）相结合，我们排除了假阳性情况，发现假阳性概率较低，为 2 × 10−4。根据 IRD 在三年内稀疏获取的 K2-415 径向速度，我们获得 K2-415b 的行星质量为 3.0 ± 2.7 M ⊕（M p < 7.5 M ⊕，95% 置信度）。作为已知拥有地球大小的凌日行星的质量最低的恒星（约 0.16 M ⊙）之一，K2-415 将成为进一步后续观测的有趣目标，包括额外的径向速度监测和凌日光谱学。
We report on the discovery of an Earth-sized transiting planet (R p = 1.015 ± 0.051 R ⊕) in a P = 4.02 day orbit around K2-415 (EPIC 211414619), an M5V star at 22 pc. The planet candidate was first identified by analyzing the light-curve data obtained by the K2 mission, and it is here shown to exist in the most recent data from TESS. Combining the light curves with the data secured by our follow-up observations, including high-resolution imaging and near-infrared spectroscopy with IRD, we rule out false-positive scenarios, finding a low false-positive probability of 2 × 10−4. Based on IRD’s radial velocities of K2-415, which were sparsely taken over three years, we obtain a planet mass of 3.0 ± 2.7 M ⊕ (M p < 7.5 M ⊕ at 95% confidence) for K2-415b. Being one of the lowest-mass stars (≈0.16 M ⊙) known to host an Earth-sized transiting planet, K2-415 will be an interesting target for further follow-up observations, including additional radial velocity monitoring and transit spectroscopy.