用JWST对偏心行星HD 80606b的食进行计时：对第二颗行星及其他动力学效应的约束
Eclipse Timing of the Eccentric Planet HD 80606b with JWST: Constraints on a Second Planet and other Dynamical Effects
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中文总结 AI 辅助
本研究结合25年视向速度与食、凌日观测，利用JWST高精度食计时约束HD 80606b的轨道进动，限制了其外第二颗行星的质量与位置，验证了轨道参数的稳定性。
中文摘要 AI 辅助
多种效应会扰动宿主恒星周围近轨道单行星的轨道特性。HD 80606 b是一颗高度偏心（ε=0.93）的系外行星，围绕G5V型恒星HD 80606运行。Laughlin等人于2009年发现这颗质量为4.16倍木星质量的行星会凌日并被HD 80606食，这使其成为系外行星研究的重要目标，可通过测光和光谱观测获取该天体的大量信息。近期JWST的食计时具有极高精度，为研究HD 80606 b的轨道是否受广义相对论、潮汐力矩或第二颗扰动行星等多种机制影响提供了机会。我们利用超过25年的视向速度数据，结合食和凌日观测，对HD 80606 b的轨道进动进行了约束，并评估这些效应（若存在）是否可观测。新模型与周期、偏心率和近点角ω的恒定值一致，对ω的变化率ω̇的约束达到了广义相对论漂移的预测水平。PRV（视向速度）和计时数据对HD 80606b外部第二颗行星的质量和位置进行了约束。JWST食计时与Pearson等人2022年预测的计时偏移，归因于该分析中仅采用了Spitzer 2009年的单次食测量，对√ε（cos ω, sin ω）的约束较差，以及早期分析中对食计时的过度加权。
英文摘要
A variety of effects can perturb the orbital properties of single planets in close orbits around their host stars. HD80606 b is a highly eccentric ($ε$=0.93) exoplanet orbiting its host G5V star, HD80606. HD80606 b became a compelling target for exoplanet research after (Laughlin et al 2009) discovered that the 4.16 MJup planet transits and is eclipsed by HD80606, thereby enabling photometric and spectroscopic observations to yield a wealth of information about the object. The exquisite precision of recent JWST eclipse timing offers an opportunity to investigate whether the orbit of HD80606 b is modified due to a variety of mechanisms, including General Relativity, tidal torques, or the presence of a second perturbing planet. We have used over 25 years of radial velocity data plus eclipse and transit observations to place limits on the precession of HD80606 b's orbit and to assess which of these effects, if any, are observable. The new models are consistent with constant values of period, eccentricity and the argument of periastron, $ω$, with a limit on $\dotω$ at the level of the predicted GR drift. The PRV and timing data limit the mass and location of a second planet external to HD80606b. Timing offsets between JWST eclipses relative to the Pearson et al (2022) predictions are attributed to the poor constraints on $\sqrtε (\cos\ ω, \sin\ ω)$ with only the single eclipse measurement available (Spitzer 2009) in that analysis and to an over-weighting of the eclipse timing in that earlier analysis.
