通过凌日时间变化（TTVs）发现LP 890-9d的证据
Evidence for LP 890-9d via Transit Timing Variations
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中文总结 AI 辅助
本研究通过分析JWST的凌日观测数据，利用凌日时间变化（TTVs）发现LP 890-9系统存在第三颗候选行星LP 890-9d的证据，其轨道周期约为4.4天。
中文摘要 AI 辅助
LP 890-9（又称SPECULOOS-2和TOI-4306）是一颗邻近的晚M型矮星，拥有两颗已确认的凌日岩质系外行星。我们分析了GO项目7073获取的20次JWST/NIRSpec PRISM对LP 890-9b和LP 890-9c的凌日观测数据，检测到具有统计显著性的凌日时间变化（TTVs），其峰峰值振幅分别约为17秒和35秒。利用解析线性TTV理论，我们发现已知的两颗行星构型无法重现测得的TTV振幅或超周期，而三颗行星模型的拟合效果显著更好。最佳拟合构型将候选第三行星LP 890-9d置于b和c行星之间，轨道周期约为4.4天；不过，当前数据无法唯一确定其轨道结构，周期在4.0-6.9天范围内仍合理。TESS对LP 890-9d的凌日不敏感，且在JWST观测中未发现该候选行星的证据，尽管相位覆盖范围（约50%至80%）强烈依赖于候选行星的轨道周期。需要对LP 890-9b和LP 890-9c进行额外的高精度凌日观测，以完善其TTV解并进一步约束第三行星的轨道性质。
英文摘要
LP 890-9, also known as SPECULOOS-2 and TOI-4306, is a nearby late-M dwarf hosting two confirmed transiting rocky exoplanets. We analyze 20 JWST/NIRSpec PRISM transits of LP 890-9b and LP 890-9c obtained as part of GO program 7073 and detect statistically significant transit timing variations (TTVs), with peak-to-peak amplitudes of ~17 s and ~35 s, respectively. Using analytic linear TTV theory, we find that the known two-planet configuration cannot reproduce the measured TTV amplitudes or super-period, whereas three-planet models provide substantially better fits. The best-fit configuration places the candidate third planet, LP 890-9d, between planets b and c, with an orbital period of ~4.4 days; however, the current data do not uniquely determine its orbital architecture, and periods spanning 4.0-6.9 days remain plausible. TESS is insensitive to transits of LP 890-9d and we find no evidence for the candidate in JWST observations, although the phase coverage (ranging from ~50% to ~80%) depends strongly on the candidate orbital period. Additional high-precision transit observations of LP 890-9b and LP 890-9c are needed to refine their TTV solutions and further constrain the orbital properties of the third planet.
发表机构
- Johns Hopkins Applied Physics Laboratory（约翰斯·霍普金斯大学应用物理实验室）
- Johns Hopkins University（约翰斯·霍普金斯大学）
- University of Bristol（布里斯托大学）
- Nevada Center for Astrophysics, University of Nevada, Las Vegas（内华达大学拉斯维加斯分校天体物理学中心）
- Department of Physics and Astronomy, University of Nevada, Las Vegas（内华达大学拉斯维加斯分校物理与天文系）
- Astronomy Department and Virtual Planetary Laboratory, University of Washington（华盛顿大学天文学系与虚拟行星实验室）
机构由 AI 辅助整理，请以论文原文为准。
