论文标题
WASP-33B节点进动的多普勒断层扫描测量
Doppler Tomographic Measurement of the Nodal Precession of WASP-33b
论文作者
论文摘要
WASP-33B是一种逆行热木星，周期为1.2天，周围绕着速度旋转和脉动A型恒星行驶。先前的一项研究发现，根据多普勒断层扫描测量值，WASP-33B的过弦从2008年略有变化。他们将这种变化归因于宿主星和未对准轨道的非零底漆引起的轨道进动。我们旨在使用在2011年在8.2m Subaru望远镜上获得的高色散光谱仪以及先前研究中使用的数据集获得的其他多型WASP-33B的多普勒层析成像数据进行确认并更精确地模拟了进动行为。使用长期轨道进动的方程式，我们约束了恒星重力四极力矩$ j_ {2} =（9.14 \ pm 0.51）\ times 10^{ - 5} $以及恒星旋转轴与视觉$ i _ {\ star} = 96^= 96^= 10}的恒星轴之间的角度。这些值更新了主恒星比以前的研究更具球形和比较赤道。我们还估计，预进期是$ \ sim $ 840年。我们还发现，黄蜂33B的进进幅度为$ \ sim $ 67摄氏度，而在主机恒星面前的WASP-33B Transs仅以$ \ sim $ \ sim $ 20 \％的整个预进时间期。
WASP-33b is a retrograde hot Jupiter with a period of 1.2 days orbiting around a rapidly rotating and pulsating A-type star. A previous study found that the transit chord of WASP-33b had changed slightly from 2008 to 2014 based on Doppler tomographic measurements. They attributed the change to orbital precession caused by the non-zero oblateness of the host star and the misaligned orbit. We aim to confirm and more precisely model the precession behavior using additional Doppler tomographic data of WASP-33b obtained with the High Dispersion Spectrograph on the 8.2m Subaru telescope in 2011, as well as the datasets used in the previous study. Using equations of a long-term orbital precession, we constrain the stellar gravitational quadrupole moment $J_{2}=(9.14\pm 0.51)\times 10^{-5}$ and the angle between the stellar spin axis and the line of sight $i_{\star}=96^{+10}_{-14}$ deg. These values update that the host star is more spherical and viewed more equator than the previous study. We also estimate that the precession period is $\sim$840 years. We also find that the precession amplitude of WASP-33b is $\sim$67 deg and WASP-33b transits in front of the host star for only $\sim$20\% of the whole precession period.
