The First Dynamical Mass Measurement in the HR 8799 System
The First Dynamical Mass Measurement in the HR 8799 System
复制标题
HR 8799 系统中的首次动态质量测量
DOI：
10.3847/2041-8213/ac0540
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
G. Marleau
中科院分区：
文献类型：
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作者：
G. Brandt;Timothy D. Brandt;T. Dupuy;D. Michalik;G. Marleau
HR 8799拥有四颗直接成像的巨行星，但没有一颗具有根据第一性原理测量的质量。我们首次对该行星系统进行了动力学质量测量，发现最内侧的行星HR 8799 e的质量为9.6−1.8+ 1.9兆焦耳。这一质量是将所有四颗行星的轨道与新的天体测量加速度检测（5σ）相结合的结果，该检测来自依巴谷-盖亚加速度目录的盖亚EDR 3版本。我们以95%的置信度发现HR 8799 e低于13 M Jup，即氘聚变的质量极限。我们推导出HR 8799 e的热启动冷却年龄为42−16+24 Myr，这与其在天鸽协中的假设成员身份非常一致，但也与β Pictureso运动群中的另一种成员身份一致。我们排除了在HR 8799 e内部存在任何额外的半长轴在103 -16 Au之间的105 − M Jup行星。我们提供了自行异常和矩阵方程来求解HR 8799中任何行星的质量，只使用行星之间的质量比。
HR 8799 hosts four directly imaged giant planets, but none has a mass measured from first principles. We present the first dynamical mass measurement in this planetary system, finding that the innermost planet HR 8799 e has a mass of 9.6−1.8+1.9MJup . This mass results from combining the well-characterized orbits of all four planets with a new astrometric acceleration detection (5σ) from the Gaia EDR3 version of the Hipparcos-Gaia Catalog of Accelerations. We find with 95% confidence that HR 8799 e is below 13 M Jup, the deuterium-fusing mass limit. We derive a hot-start cooling age of 42−16+24 Myr for HR 8799 e that agrees well with its hypothesized membership in the Columba association but is also consistent with an alternative suggested membership in the β Pictoris moving group. We exclude the presence of any additional ≳5 − M Jup planets interior to HR 8799 e with semimajor axes between ≈3–16 au. We provide proper motion anomalies and a matrix equation to solve for the mass of any of the planets of HR 8799 using only mass ratios between the planets.