TESS Full Orbital Phase Curve of the WASP-18b System
Article
Article Title | TESS Full Orbital Phase Curve of the WASP-18b System |
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ERA Journal ID | 1048 |
Article Category | Article |
Authors | Shporer, Avi (Author), Wong, Ian (Author), Huang, Chelsea X. (Author), Line, Michael R. (Author), Stassun, Keivan G. (Author), Fetherolf, Tara (Author), Kane, Stephen R. (Author), Bouma, Luke G. (Author), Daylan, Tansu (Author), Gunther, Maximilian N. (Author), Ricker, George R. (Author), Latham, David W. (Author), Vanderspek, Roland (Author), Seager, Sara (Author), Winn, Joshua N. (Author), Jenkins, Jon M. (Author), Glidden, Ana (Author), Berta-Thompson, Zach (Author), Ting, Eric B. (Author), Li, Jie (Author) and Haworth, Kari (Author) |
Journal Title | The Astronomical Journal |
Journal Citation | 157 (5), pp. 1-12 |
Article Number | 178 |
Number of Pages | 12 |
Year | 2019 |
Publisher | IOP Publishing |
Place of Publication | United States |
ISSN | 0004-6256 |
1538-3881 | |
Digital Object Identifier (DOI) | https://doi.org/10.3847/1538-3881/ab0f96 |
Web Address (URL) | https://iopscience.iop.org/article/10.3847/1538-3881/ab0f96 |
Abstract | We present a visible-light full orbital phase curve of the transiting planet WASP-18b measured by the TESS mission. The phase curve includes the transit, secondary eclipse, and sinusoidal modulations across the orbital phase shaped by the planet's atmospheric characteristics and the star-planet gravitational interaction. We measure the beaming (Doppler boosting) and tidal ellipsoidal distortion phase modulations and show that the amplitudes of both agree with theoretical expectations. We find that the light from the planet's dayside hemisphere occulted during secondary eclipse, with a relative brightness of 341-18 +17 ppm, is dominated by thermal emission, leading to an upper limit on the geometric albedo in the TESS band of 0.048 (2σ). We also detect the phase modulation due to the planet's atmosphere longitudinal brightness distribution. We find that its maximum is well aligned with the substellar point to within 2.°9 (2σ). We do not detect light from the planet's nightside hemisphere, with an upper limit of 43 ppm (2σ), which is 13% of the dayside brightness. The low albedo, lack of atmospheric phase shift, and inefficient heat distribution from the day to night hemispheres that we deduce from our analysis are consistent with theoretical expectations and similar findings for other strongly irradiated gas giant planets. This work demonstrates the potential of TESS data for studying the full orbital phase curves of transiting systems. Finally, we complement our study by looking for transit timing variations (TTVs) in the TESS data combined with previously published transit times, although we do not find a statistically significant TTV signal. |
Keywords | planetary systems; planets and satellites: atmospheres; stars: individual (WASP-18, TIC 100100827, TOI 185); Astrophysics - Earth and Planetary Astrophysics; Astrophysics - Solar and Stellar Astrophysics |
Contains Sensitive Content | Does not contain sensitive content |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | For access to this article, please click on the URL link provided. |
Byline Affiliations | Massachusetts Institute of Technology, United States |
Arizona State University, United States | |
Vanderbilt University, United States | |
University of California, United States | |
Princeton University, United States | |
Center for Astrophysics Harvard and Smithsonian, United States | |
National Aeronautics and Space Administration (NASA), United States | |
University of Colorado Boulder, United States | |
NASA Ames Research Center, United States | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q7234/tess-full-orbital-phase-curve-of-the-wasp-18b-system
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