揭示熔岩世界的闪耀本质：TESS 小型行星相位曲线
Revealing the Shiny Nature of Lava Worlds: Small Planet Phase Curves with TESS
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中文总结 AI 辅助
本研究利用TESS可见光相位曲线群体分析，揭示熔岩世界普遍具有高几何反照率，支持反射性硅酸盐云冷却昼侧的观点，并预测PLATO任务将提供更严格约束。
中文摘要 AI 辅助
近期热辐射观测表明，“熔岩世界”——即表面温度足以熔化硅酸盐的类地系外行星——在群体层面上可能拥有大气层。这一证据来自测得的昼侧亮度温度远低于暗色、最大程度炽热的裸露岩石的预期值。然而，这些结果在厚大气层将热量输送到行星夜侧与高反照率反射入射辐射这两种解释之间是简并的。这种简并可以通过可见光相位曲线观测来解决，该观测能够约束行星反射的光量。\n在此，我们呈现对 $R\lesssim5\\,R_{\oplus}$ 系外行星的可见光 TESS 相位曲线进行的群体层面分析。我们通过定义一个“反射光谱度量”来筛选该群体，该度量旨在量化反射光观测的相对信噪比。我们报告了 LTT 9779 b 以及熔岩世界 TOI-2431 b、TOI-561 b、55 Cancri e、K2-141 b 和 TOI-1444 b 的 TESS 相位曲线信号的新 $>3\\,σ$ 探测。我们利用这些结果以及先前来自 Kepler 和 CHEOPS 的结果，同质地推导出这些行星的几何反照率，揭示熔岩世界通常表现出高反照率，而类似温度下的热木星则测得低几何反照率。这些结果支持了一个新兴图景：这些世界上的反射性硅酸盐云冷却了它们的昼侧。即将到来的 PLATO 任务预计将严格约束熔岩世界的反射光相位曲线。
英文摘要
Recent thermal emission observations suggest that `lava worlds'--Earth-sized exoplanets hot enough to melt their silicate surfaces--have atmospheres on a population-level. This evidence comes from measured dayside brightness temperatures much lower than expected for a dark, maximally hot bare rock. However, these results are degenerate between a thick atmosphere advecting heat to the planet's nightside or a high albedo reflecting incoming radiation. This degeneracy can be resolved through visible light phase curve observations, which can constrain how much light is reflected by the planet. Here, we present a population-level analysis of the visible-light TESS phase curves of $R\lesssim5\,R_{\oplus}$ exoplanets. We select the population by defining a `Reflection Spectroscopy Metric' meant to quantify the relative signal-to-noise of reflected light observations. We report new $>3\,σ$ detections of the TESS phase curve signals of LTT 9779 b and the lava worlds TOI-2431 b, TOI-561 b, 55 Cancri e, K2-141 b, and TOI-1444 b. We use these results and previous results from Kepler and CHEOPS to homogeneously derive geometric albedos for these planets, revealing that lava worlds generally show high albedos compared to the low geometric albedos measured for hot Jupiters at similar temperatures. These results support an emerging picture of reflective silicate clouds on these worlds cooling their daysides. The upcoming PLATO mission is expected to tightly constrain the reflected light phase curves of lava worlds.
发表机构
- University of Chicago（芝加哥大学）
- University of Hawai’i（夏威夷大学）
机构由 AI 辅助整理，请以论文原文为准。
