论文标题
及时的十二生肉系外行星。 xi。年轻的M矮人托运行星K2-25B的轨道和辐射环境
Zodiacal Exoplanets in Time. XI. The Orbit and Radiation Environment of the Young M Dwarf-Hosted Planet K2-25b
论文作者
论文摘要
矮星是搜索地球大小和潜在地面行星的高优先级目标，但是它们的行星系统可能与太阳能恒星的行星系统形成和发展。为了探索这些系统的演变，我们获得了绕〜650 Myr over Hyades M矮k2-25的海王星大小的行星的传输光谱和光度法。分析了地球多普勒“阴影”诱导的光谱线形状变化表明，行星的轨道与Stellar赤道（Lambda = -1.7+5.8/-3.7 deg）紧密地对齐，并且以前的工作可能会在Co-Planet On Co-Planet Onbit上遇到怪异的怪异轨道。我们检测到在运输过程中1083 nm处的He I线的深度没有显着差异。大气逃脱的模型作为带有太阳能组成的等温帕克风，表明，与左右的预测相比，这种非检测不是约束的。以这种速度，像海王星一样的行星需要至少几个回旋才能演变成岩石的超级地球。
M dwarf stars are high-priority targets for searches for Earth-size and potentially Earth-like planets, but their planetary systems may form and evolve in very different circumstellar environments than those of solar-type stars. To explore the evolution of these systems, we obtained transit spectroscopy and photometry of the Neptune-size planet orbiting the ~650 Myr-old Hyades M dwarf K2-25. An analysis of the variation in spectral line shape induced by the Doppler "shadow" of the planet indicate that the planet's orbit is closely aligned with the stellar equator (lambda = -1.7+5.8/-3.7 deg), and that an eccentric orbit found by previous work could arise from perturbations by another planet on a co-planar orbit. We detect no significant variation in the depth of the He I line at 1083 nm during transit. A model of atmospheric escape as a isothermal Parker wind with a solar composition show that this non-detection is not constraining compared to escape rate predictions of ~0.1 Mearth/Gyr; at such rates, at least several Gyr are required for a Neptune-like planet to evolve into a rocky super-Earth.
