Nodal precession of WASP-33b for 11 yr by Doppler tomographic and transit photometric observations
Nodal precession of WASP-33b for 11 yr by Doppler tomographic and transit photometric observations
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通过多普勒断层扫描和凌日光度观测观察 WASP-33b 11 年的节点进动
DOI：
10.1093/mnras/stac620
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发表时间：
2022
影响因子：
4.8
通讯作者：
Ka
中科院分区：
文献类型：
--
作者：
Watanabe Noriharu;Narita Norio;Palle Enric;Fukui Akihiko;Kusakabe Nobuhiko;Parviainen Hannu;Murgas Felipe;Casasayas-Barris Nuria;Johnson Marshall C;Sato Bun’ei;Livingston John H;de Leon Jerome P;Mori Mayuko;Nishiumi Taku;Terada Yuka;Esparza-Borges Emma;Ka
WASP-33b是一颗环绕着一颗热星的热木星，它是一个罕见的发现了节进动的系统。我们通过增加新的观测点更新了WASP-33b的节点进动模型。因此，我们发现了一个跨越11年的节点进动运动。我们给出了8个数据集的齐次多普勒层析分析，其中包括2008年至2019年从TS23和HIDES获得的两个新数据集，以说明WASP-33b的预测自旋轨道倾角及其影响参数的变化。我们还根据Muscat和MuSCAT2在2017年和2018年捕获的光度凌日观测给出了它的影响参数。我们从这两个轨道参数的时间变化模型中推导出了它的真实自旋轨道倾角ψ、恒星自旋倾角I和恒星引力四极矩J_2。我们得到了德格，德格，和。我们的J2值比理论预测值略小，这可能表明它的实际恒星内部结构与理论不同。我们推导了节点进动速度−1及其周期，发现∼-33b在整个节点进动周期中只有20%的时间在Wasp-33前面经过。
WASP-33b, a hot Jupiter around a hot star, is a rare system in which nodal precession has been discovered. We updated the model for the nodal precession of WASP-33b by adding new observational points. Consequently, we found a motion of the nodal precession spanning 11 yr. We present homogenous Doppler tomographic analyses of eight data sets, including two new data sets from TS23 and HIDES, obtained between 2008 and 2019, to illustrate the variations in the projected spin–orbit obliquity of WASP-33b and its impact parameter. We also present its impact parameters based on photometric transit observations captured by MuSCAT in 2017 and MuSCAT2 in 2018. We derived its real spin–orbit obliquity ψ, stellar spin inclinationis, and stellar gravitational quadrupole momentJ2from the time variation models of the two orbital parameters. We obtaineddeg,deg, and. OurJ2value was slightly smaller than the theoretically predicted value, which may indicate that its actual stellar internal structure is different from the theoretical one. We derived the nodal precession speeddeg yr−1, and its periodyr, and found that WASP-33b transits in front of WASP-33 for only ∼ 20 per cent of the entire nodal precession period.