AI 中文总结
分析TESS五个扇区相位曲线，发现WASP-43b中食深度130±34 ppm及44±18度东向偏移，表明其白天面无云且存在热深层大气。
AI 中文摘要
相位曲线测绘根据波长的不同探测各种大气特性：热相位曲线主要由大气发射主导，而可见光和近红外相位曲线则包含反射光。因此，测得的行星相位曲线偏移——最亮半球相对于恒星直下点的纵向偏移——对发射主导与反射主导波段中不同的大气过程敏感。特别是，具有部分西侧白天面反射云覆盖的行星，其反射光相位曲线偏移相对于热波长呈西向偏移。在本工作中，我们分析了热木星 WASP-43b 的五个 TESS 扇区相位曲线观测数据，并与先前发表的多波段分析结果进行比较，以研究其白天面云覆盖情况。我们测得中食深度为 130 ± 34 ppm，表明 TESS 波段的行星亮度超出了基于观测和模型热发射的预期。若将此多余通量归因于反射，我们估算出低几何反照率 A_g ≈ 0.05 - 0.10。这些发现支持了先前关于 WASP-43b 白天面缺乏显著云覆盖的结论。相位曲线测绘揭示出 44 ± 18 度的大东向相位曲线偏移，显著东于 JWST 在较长波长下测得的偏移，为无云白天面提供了证据。TESS 波段多余发射的探测以及测得的大东向相位曲线偏移均支持 WASP-43b 拥有一个在短波长下被探测到的热深层大气的结论。
英文摘要
Phase-curve mapping probes various atmospheric properties depending on wavelength: thermal phase curves are dominated by atmospheric emission, while visible and near-infrared phase curves include reflected light. The measured planetary phase curve offset--the longitudinal offset of the hemisphere of peak brightness from the substellar point--is therefore sensitive to differing atmospheric processes in emission-dominated vs. reflection-dominated bands. In particular, planets with partial western-dayside reflective cloud coverage show a westward reflected-light phase-curve offset relative to the thermal wavelengths. In this work, we analyze five sectors of TESS phase curve observations of the hot Jupiter WASP-43b and compare to previous published multi-band analyses to investigate dayside cloud coverage. We measure a mid-eclipse depth of 130 $\pm$ 34 ppm, indicating excess TESS planetary brightness above expectations based on observed and modeled thermal emission. Attributing this excess flux to reflection, we estimate a low geometric albedo of $A_g$ $\approx$ 0.05 - 0.10. These findings support previous conclusions that WASP-43b lacks any significant cloud coverage on its dayside. Phase-curve mapping reveals a large eastward phase curve offset of 44 $\pm$ 18 degrees, significantly eastward of offsets measured at longer wavelengths with JWST, providing evidence for a cloud-free dayside. Both the detection of excess emission in the TESS band and the large measured eastward phase-curve offset support the conclusion that WASP-43b has a hot deep atmosphere that is probed at short wavelengths.
