The Hot Neptune WASP-166 b with ESPRESSO – I. Refining the planetary architecture and stellar variability
The Hot Neptune WASP-166 b with ESPRESSO – I. Refining the planetary architecture and stellar variability
复制标题
热海王星 WASP-166 b 与 ESPRESSO — I. 完善行星结构和恒星变异性
DOI：
10.1093/mnras/stac2178
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发表时间：
2022
影响因子：
4.8
通讯作者：
Buchschacher, N.
中科院分区：
文献类型：
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作者：
Doyle, L.;Cegla, H. M.;Bryant, E.;Bayliss, D.;Lafarga, M.;Anderson, D. R.;Allart, R.;Bourrier, V.;Brogi, M.;Buchschacher, N.
在本文中，我们提出了高分辨率的光谱凌日观测ESTERO的超海王星WASP-166 B。除了光谱ESTO数据，我们分析测光数据从TESS的6个WASP-166 B过渡沿着与同时NGTS观测的ESTO运行。这些观测结果被用来拟合行星参数，以及评估ESTERO观测期间存在的恒星活动水平（例如斑点交叉，耀斑）。我们利用重新加载的罗西特麦克劳克林（RRM）技术空间解决恒星表面，表征中心到边缘对流引起的变化，并完善恒星行星的相似性。我们发现WASP-166 B的预测折射率为vsin（i）= 4.97 ± 0.09 km s− 1，这与文献中的结果一致。我们能够表征中心到边缘的对流变化，作为星星表面上的粒化的结果，在几km s-1的数量级上，这是第一次。我们使用线性、二次和三次模型模拟了中心到边缘的对流变化，首选三次模型。此外，通过同时模拟差异旋转和中心到边缘的对流变化，我们能够反演潜在的反太阳差异旋转切变（α =-0.5）和恒星倾角（i*= 42.03或133.64，如果星星指向我们或远离我们）。最后，我们调查的形状的互相关函数的变化作为一个函数的肢体角度和比较我们的结果磁流体动力学模拟。
In this paper, we present high-resolution spectroscopic transit observations from ESPRESSO of the super-Neptune WASP-166 b. In addition to spectroscopic ESPRESSO data, we analyse photometric data fromTESSof six WASP-166 b transits along with simultaneous NGTS observations of the ESPRESSO runs. These observations were used to fit for the planetary parameters as well as assessing the level of stellar activity (e.g. spot crossings, flares) present during the ESPRESSO observations. We utilize the reloaded Rossiter McLaughlin (RRM) technique to spatially resolve the stellar surface, characterizing the centre-to-limb convection-induced variations, and to refine the star–planet obliquity. We find WASP-166 b has a projected obliquity ofandvsin (i) = 4.97 ± 0.09 km s−1which is consistent with the literature. We were able to characterize centre-to-limb convective variations as a result of granulation on the surface of the star on the order of a few km s−1for the first time. We modelled the centre-to-limb convective variations using a linear, quadratic, and cubic model with the cubic being preferred. In addition, by modelling the differential rotation and centre-to-limb convective variations simultaneously, we were able to retrieve a potential antisolar differential rotational shear (α ∼ −0.5) and stellar inclination (i*either 42.03or 133.64if the star is pointing towards or away from us). Finally, we investigate how the shape of the cross-correlation functions change as a function of limb angle and compare our results to magnetohydrodynamic simulations.