Kipping David, Bryson Steve, Burke Chris, Christiansen Jessie, Hardegree-Ullman Kevin, Quarles Billy, Hansen Brad, Szulágyi Judit, Teachey Alex
Department of Astronomy, Columbia University, New York, NY USA.
NASA Ames Research Center, Mountain View, CA USA.
Nat Astron. 2022;6(3):367-380. doi: 10.1038/s41550-021-01539-1. Epub 2022 Jan 13.
Exomoons represent a crucial missing puzzle piece in our efforts to understand extrasolar planetary systems. To address this deficiency, we here describe an exomoon survey of 70 cool, giant transiting exoplanet candidates found by Kepler. We identify only one exhibiting a moon-like signal that passes a battery of vetting tests: Kepler-1708 b. We show that Kepler-1708 b is a statistically validated Jupiter-sized planet orbiting a Sun-like quiescent star at 1.6 au. The signal of the exomoon candidate, Kepler-1708 b-i, is a 4.8 effect and is persistent across different instrumental detrending methods, with a 1% false-positive probability via injection-recovery. Kepler-1708 b-i is ~2.6 Earth radii and is located in an approximately coplanar orbit at ~12 planetary radii from its ~1.6 au Jupiter-sized host. Future observations will be necessary to validate or reject the candidate.
系外卫星是我们在理解太阳系外行星系统的努力中至关重要却缺失的拼图碎片。为解决这一不足，我们在此描述了一项对开普勒发现的70颗低温、巨型凌日系外行星候选体的系外卫星调查。我们仅识别出一个呈现出类似卫星信号且通过一系列审查测试的目标：开普勒-1708 b。我们表明，开普勒-1708 b是一颗经统计验证的木星大小的行星，在距离一颗类似太阳的宁静恒星1.6天文单位处公转。系外卫星候选体开普勒-1708 b-i的信号是一个4.8的效应，并且在不同的仪器去趋势方法中都持续存在，通过注入-恢复法得出的假阳性概率为1%。开普勒-1708 b-i约为2.6个地球半径，位于距离其1.6天文单位的木星大小的主恒星约12个行星半径处的近似共面轨道上。未来的观测对于验证或排除该候选体将是必要的。
