Detection of the tidal deformation of WASP-103b at 3 s with CHEOPS
Detection of the tidal deformation of WASP-103b at 3 s with CHEOPS
复制标题
利用 CHEOPS 检测 WASP-103b 3 s 时的潮汐变形
DOI：
10.1051/0004-6361/202142196
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发表时间：
2022
影响因子：
6.5
通讯作者：
Barros S
中科院分区：
文献类型：
--
作者：
Barros S
超短周期行星与其宿主星星发生强烈的潮汐相互作用，导致行星变形和轨道潮汐衰减。AimsWASP-103 b是其凌日光变曲线中预期变形特征最高的系外行星，也是预期螺旋进入时间最短的系外行星之一。测量行星的潮汐变形将使我们能够估计二度流体的洛夫数，并深入了解行星的内部结构。此外，测量潮汐衰减时间尺度将使我们能够估计恒星潮汐质量因子，这是关键，以约束stellar physics.MethodsWe获得了12个凌日光曲线的WASP-103 b与CHEOPS（CHARACTERISING Exoplanet Satellite）估计的潮汐变形和潮汐衰减的这个极端的系统。我们模拟了高精度CHEOPS过境光变曲线与系统的仪器噪声使用多维高斯过程回归通知一组仪器参数。为了模拟潮汐变形，我们使用了一个参数化模型，使我们能够确定行星的二度流体Love数。我们结合我们的光变曲线与以前观察到的过境WASP-103 b与thehubbleSpaceTelescope（HST）andSpitzer增加光变曲线的信噪比和更好地区分分钟信号预期从行星deformation.ResultsWe估计径向勒夫数WASP-103 b为。这是第一次直接从系外行星的凌日光变曲线中检测到潮汐形变（在3σ处）。将CHEOPS、HST和Spitzer光变曲线的渡越时间与文献中的其他渡越时间相结合，我们发现WASP-103 b没有显著的轨道周期变化。然而，数据显示轨道周期增加而不是减少的暗示，正如潮汐衰变所预期的那样。这可能是由于一个视觉伴星星星，如果这个星星是绑定，Applegate效应，或统计artefact.ConclusionsThe估计的爱数的WASP-103 b是类似的木星。这将使我们能够限制WASP-103 b的内部结构和组成，这可能为热膨胀提供线索。詹姆斯韦伯太空望远镜的未来观测可以更好地限制WASP-103 b的径向勒夫数，因为它们的高信噪比和红外线中较小的临边变暗特征。需要一个较长的时间基线来约束该系统中的潮汐衰减。
ContextUltra-short period planets undergo strong tidal interactions with their host star which lead to planet deformation and orbital tidal decay.AimsWASP-103b is the exoplanet with the highest expected deformation signature in its transit light curve and one of the shortest expected spiral-in times. Measuring the tidal deformation of the planet would allow us to estimate the second degree fluid Love number and gain insight into the planet’s internal structure. Moreover, measuring the tidal decay timescale would allow us to estimate the stellar tidal quality factor, which is key to constraining stellar physics.MethodsWe obtained 12 transit light curves of WASP-103b with the CHaracterising ExOplanet Satellite (CHEOPS) to estimate the tidal deformation and tidal decay of this extreme system. We modelled the high-precision CHEOPS transit light curves together with systematic instrumental noise using multi-dimensional Gaussian process regression informed by a set of instrumental parameters. To model the tidal deformation, we used a parametrisation model which allowed us to determine the second degree fluid Love number of the planet. We combined our light curves with previously observed transits of WASP-103b with theHubbleSpace Telescope (HST) andSpitzerto increase the signal-to-noise of the light curve and better distinguish the minute signal expected from the planetary deformation.ResultsWe estimate the radial Love number of WASP-103b to be . This is the first time that the tidal deformation is directly detected (at 3σ) from the transit light curve of an exoplanet. Combining the transit times derived from CHEOPS, HST, andSpitzerlight curves with the other transit times available in the literature, we find no significant orbital period variation for WASP-103b. However, the data show a hint of an orbital period increase instead of a decrease, as is expected for tidal decay. This could be either due to a visual companion star if this star is bound, the Applegate effect, or a statistical artefact.ConclusionsThe estimated Love number of WASP-103b is similar to Jupiter’s. This will allow us to constrain the internal structure and composition of WASP-103b, which could provide clues on the inflation of hot Jupiters. Future observations withJames WebbSpace Telescope can better constrain the radial Love number of WASP-103b due to their high signal-to-noise and the smaller signature of limb darkening in the infrared. A longer time baseline is needed to constrain the tidal decay in this system.