论文标题
在苔丝时代重新访问Kelt-19AB，WASP-156B和WASP-121B
Revisiting KELT-19Ab, WASP-156b and WASP-121b in the TESS Era
论文作者
论文摘要
我们介绍了Kelt-19AB，WASP-156B和WASP-121B的过境深度的重新分析，包括来自过境系外行星调查卫星（TESS）的数据。大型$ \ sim $ 21 $ \ arcsec $ tess像素和点传播功能会导致附近物体对恒星通量的重大污染。我们使用Gaia数据适合和删除此贡献，为此校正提供通用软件。与早期工作相比，我们发现这三个来源具有更大的倾向。对于WASP-121B，与2分钟的节奏数据相比，使用30分钟的节奏数据时，我们发现倾斜度的值明显较小（13.5度）。使用仿真，我们证明了外部球星与星的半径比（$ r_ {p}/r _ {\ ast} $）相对于用较大的采样间隔的数据而言，偏差较小，尽管过度抽样校正减轻了偏见。这对于得出频带之间的次级过境差异特别重要。我们发现，苔丝带中系外行星与恒星的半径比（$ r_ {p}/r _ {\ ast} $）的半径比Kelt-19ab的先前工作小7.5 $σ$，但对于WASP-156B和WASP-121B的SIM $ 2 $σ$一致。差异可能是由于分析中的特定选择，而不一定是由于大气特征的存在。 Kelt-19ab的结果可能有利于雾霾主导的气氛。我们找不到$ \ sim $ 0.95 \，$μ$ m的水功能污染这些恒星中的过境深度，但表明，使用光度的精度为500ppm，并且在整个过境中进行了大约200个观测值，可以在更狭窄的$ z-$ band中检测到此功能。
We present a re-analysis of transit depths of KELT-19Ab, WASP-156b, and WASP-121b, including data from the Transiting Exoplanet Survey Satellite (TESS). The large $\sim$21$\arcsec$ TESS pixels and point spread function result in significant contamination of the stellar flux by nearby objects. We use Gaia data to fit for and remove this contribution, providing general-purpose software for this correction. We find all three sources have a larger inclination, compared to earlier work. For WASP-121b, we find significantly smaller values (13.5 degrees) of the inclination when using the 30 minutes cadence data compared to the 2 minutes cadence data. Using simulations, we demonstrate that the radius ratio of exoplanet to star ($R_{p}/R_{\ast}$) is biased small relative to data taken with a larger sampling interval although oversampling corrections mitigate the bias. This is particularly important for deriving sub-percent transit differences between bands. We find the radius ratio of exoplanet to star ($R_{p}/R_{\ast}$) in the TESS band is 7.5$σ$ smaller than previous work for KELT-19Ab, but consistent to within $\sim$2$σ$ for WASP-156b and WASP-121b. The difference could be due to specific choices in the analysis, not necessarily due to the presence of atmospheric features. The result for KELT-19Ab possibly favors a haze-dominated atmosphere. We do not find evidence for the $\sim$0.95\,$μ$m water feature contaminating transit depths in the TESS band for these stars but show that with photometric precision of 500ppm and with a sampling of about 200 observations across the entire transit, this feature could be detectable in a more narrow $z-$band.
