The First Habitable-zone Earth-sized Planet from TESS. I. Validation of the TOI-700 System
The First Habitable-zone Earth-sized Planet from TESS. I. Validation of the TOI-700 System
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DOI：
10.3847/1538-3881/aba4b2
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发表时间：
2020-01
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通讯作者：
E. Gilbert;T. Barclay;J. Schlieder;E. Quintana;B. Hord;V. Kostov;E. Lopez;J. Rowe;Kelsey L. Hoffma
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作者：
E. Gilbert;T. Barclay;J. Schlieder;E. Quintana;B. Hord;V. Kostov;E. Lopez;J. Rowe;Kelsey L. Hoffma
我们提出了一个三行星系统的发现和验证附近（31.1 pc）M2矮星星TOI-700（TIC 150428135）。TOI-700位于南半球的TESS连续观测区;跨越11个扇区的观测显示了三颗行星，半径从1 R到2.6 R，轨道周期从9.98到37.43天。地面跟踪与诊断审查和验证测试相结合，使我们能够排除常见的天体物理假阳性情况，并验证行星系统。最外层的行星TOI-700 d，半径为1.19 ± 0.11 R，保守估计位于主星星的适居带内，在那里它接收到的来自其星星的通量约为地球日射量的86%。与其他一些在可居住区拥有地球大小行星的低质量恒星相比，TOI-700表现出低水平的恒星活动，这为研究影响大气逃逸的各种条件下的潜在岩石行星提供了宝贵的机会。虽然詹姆斯·韦伯太空望远镜（JWST）对TOI-700 d的大气特征描述将具有挑战性，但更大的亚海王星TOI-700 c（R = 2.63 R）将是JWST和未来天基天文台的绝佳目标。TESS计划再次观测南半球，它将在其扩展的使命中监测TOI-700的另外11个扇区。这些观测应该允许进一步限制已知的行星参数，并搜索系统中的其他行星和凌日时间变化。
We present the discovery and validation of a three-planet system orbiting the nearby (31.1 pc) M2 dwarf star TOI-700 (TIC 150428135). TOI-700 lies in the TESS continuous viewing zone in the Southern Ecliptic Hemisphere; observations spanning 11 sectors reveal three planets with radii ranging from 1 R⊕ to 2.6 R⊕ and orbital periods ranging from 9.98 to 37.43 days. Ground-based follow-up combined with diagnostic vetting and validation tests enables us to rule out common astrophysical false-positive scenarios and validate the system of planets. The outermost planet, TOI-700 d, has a radius of 1.19 ± 0.11 R⊕ and resides within a conservative estimate of the host star’s habitable zone, where it receives a flux from its star that is approximately 86% of Earth’s insolation. In contrast to some other low-mass stars that host Earth-sized planets in their habitable zones, TOI-700 exhibits low levels of stellar activity, presenting a valuable opportunity to study potentially rocky planets over a wide range of conditions affecting atmospheric escape. While atmospheric characterization of TOI-700 d with the James Webb Space Telescope (JWST) will be challenging, the larger sub-Neptune, TOI-700 c (R = 2.63 R⊕), will be an excellent target for JWST and future space-based observatories. TESS is scheduled to once again observe the Southern Hemisphere, and it will monitor TOI-700 for an additional 11 sectors in its extended mission. These observations should allow further constraints on the known planet parameters and searches for additional planets and transit timing variations in the system.