The stable climate of KELT-9b
(2022) In Astronomy and Astrophysics 666.- Abstract
- 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... (More)
- 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% © 2022 EDP Sciences. All rights reserved. (Less)
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- author
- Jones, K. ; Davies, M.B. LU and Wang Jungo, W.
- author collaboration
- organization
- publishing date
- 2022
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Eclipses, Instrumentation: photometers, Occultations, Planets and satellites: atmospheres, Planets and satellites: gaseous planets, Techniques: photometric, Atmospheric temperature, Dissociation, Emission spectroscopy, Orbits, Photometry, Planets, Satellites, Band pass, Eclipse, Gas giant, Molecular hydrogen, Occultation, Planet and satellite: gaseous planet, Planets and satellites, Energy transfer
- in
- Astronomy and Astrophysics
- volume
- 666
- article number
- A118
- publisher
- EDP Sciences
- external identifiers
-
- scopus:85166667721
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361/202243823
- language
- English
- LU publication?
- yes
- id
- f388eb5d-4cb4-41aa-97da-fb1dc5761e94
- date added to LUP
- 2023-12-22 15:56:33
- date last changed
- 2023-12-22 15:57:19
@article{f388eb5d-4cb4-41aa-97da-fb1dc5761e94,
abstract = {{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% © 2022 EDP Sciences. All rights reserved.}},
author = {{Jones, K. and Davies, M.B. and Wang Jungo, W.}},
issn = {{0004-6361}},
keywords = {{Eclipses; Instrumentation: photometers; Occultations; Planets and satellites: atmospheres; Planets and satellites: gaseous planets; Techniques: photometric; Atmospheric temperature; Dissociation; Emission spectroscopy; Orbits; Photometry; Planets; Satellites; Band pass; Eclipse; Gas giant; Molecular hydrogen; Occultation; Planet and satellite: gaseous planet; Planets and satellites; Energy transfer}},
language = {{eng}},
publisher = {{EDP Sciences}},
series = {{Astronomy and Astrophysics}},
title = {{The stable climate of KELT-9b}},
url = {{http://dx.doi.org/10.1051/0004-6361/202243823}},
doi = {{10.1051/0004-6361/202243823}},
volume = {{666}},
year = {{2022}},
}