Jones, K.; Morris, B. M.; Demory, B.-O.; Heng, K.; Hooton, M. J.; Billot, N.; Ehrenreich, D.; Hoyer, S.; Simon, A. E.; Lendl, M.; Demangeon, O. D. S.; Sousa, S. G.; Bonfanti, A.; Wilson, T. G.; Salmon, S.; Csizmadia, Sz.; Parviainen, H.; Bruno, G.; Alibert, Y.; Alonso, R.; ... (2022). The stable climate of KELT-9b,. Astronomy and astrophysics, 666, A118. EDP Sciences 10.1051/0004-6361/202243823
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Even among the most irradiated gas giants, so-called ultra-hot Jupiters, KELT-9b stands out as the hottest planet thus far discovered with a dayside temperature of over 4500 K. At these extreme irradiation levels, we expect an increase in heat redistribution efficiency and a low Bond albedo owed to an extended atmosphere with molecular hydrogen dissociation occurring on the planetary dayside. We present new photometric observations of the KELT-9 system throughout 4 full orbits and 9 separate occultations obtained by the 30 cm space telescope CHEOPS. The CHEOPS bandpass, located at optical wavelengths, captures the peak of the thermal emission spectrum of KELT-9b. In this work we simultaneously analyse CHEOPS phase curves along with public phase curves from TESS and Spitzer to infer joint constraints on the phase curve variation, gravity-darkened transits, and occultation depth in three bandpasses, as well as derive 2D temperature maps of the atmosphere at three different depths. We find a day-night heat redistribution efficiency of ~0.3 which confirms expectations of enhanced energy transfer to the planetary nightside due to dissociation and recombination of molecular hydrogen. We also calculate a Bond albedo consistent with zero. We find no evidence of variability of the brightness temperature of the planet, excluding variability greater than 1%
Item Type: |
Journal Article (Original Article) |
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Division/Institute: |
08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences 08 Faculty of Science > Physics Institute 10 Strategic Research Centers > Center for Space and Habitability (CSH) 08 Faculty of Science > Physics Institute > NCCR PlanetS |
UniBE Contributor: |
Jones, Kathryn Dawn, Demory, Brice-Olivier Denys, Heng, Kevin, Alibert, Yann Daniel Pierre, Beck, Thomas, Benz, Willy, Broeg, Christopher, Fortier, A., Thomas, Nicolas, Wang, Wei (B) |
Subjects: |
500 Science > 520 Astronomy 500 Science > 530 Physics 600 Technology > 620 Engineering 500 Science > 570 Life sciences; biology 600 Technology > 610 Medicine & health |
ISSN: |
0004-6361 |
Publisher: |
EDP Sciences |
Language: |
English |
Submitter: |
Wei Wang Jungo |
Date Deposited: |
22 Mar 2023 07:33 |
Last Modified: |
29 Mar 2023 23:38 |
Publisher DOI: |
10.1051/0004-6361/202243823 |
BORIS DOI: |
10.48350/180446 |
URI: |
https://boris.unibe.ch/id/eprint/180446 |