Warm Jupiters Beyond the Tidal Synchronization Limit may Exhibit a Wide Range of Secondary Eclipse Depths
With the JWST we can now characterize the atmospheres of longer-orbit planets, but this moves us into a regime where we cannot assume that tidal forces from the star have eroded the planets’ obliquities and synchronized their rotation rates. These rotation vectors may be tracers of formation and evo...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astronomical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-3881/acd342 |
| _version_ | 1797698614129065984 |
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| author | Emily Rauscher Nicolas B. Cowan Rodrigo Luger |
| author_facet | Emily Rauscher Nicolas B. Cowan Rodrigo Luger |
| author_sort | Emily Rauscher |
| collection | DOAJ |
| description | With the JWST we can now characterize the atmospheres of longer-orbit planets, but this moves us into a regime where we cannot assume that tidal forces from the star have eroded the planets’ obliquities and synchronized their rotation rates. These rotation vectors may be tracers of formation and evolution histories and also enable a range of atmospheric circulation states. Here we delineate the orbital space over which tidal synchronization and alignment assumptions may no longer apply and present three-dimensional atmospheric models of a hypothetical warm Jupiter over a range of rotation rates and obliquities. We simulate the secondary eclipses of this planet for different possible viewing orientations and times during its orbital, seasonal cycle. We find that the eclipse depth can be strongly influenced by the rotation rate and obliquity through the timing of the eclipse relative to the planet’s seasonal cycle, and advise caution in attempting to derive properties such as albedo or day–night transport from this measurement. We predict that if warm Jupiters beyond the tidal limit have intrinsic diversity in their rotation vectors, then this will manifest itself as dispersion in their secondary eclipse depths. We explore eclipse mapping as a way to uniquely constrain the rotation vector of warm Jupiters but find that the associated signals are likely at the edge of the JWST performance. Nevertheless, as the JWST begins to measure the secondary eclipses of longer-orbital-period planets, we should expect to observe the consequences of a wider range of rotation states and circulation patterns. |
| first_indexed | 2024-03-12T03:56:53Z |
| format | Article |
| id | doaj.art-9c4b6378413149c19dccddacb8001d55 |
| institution | Directory Open Access Journal |
| issn | 1538-3881 |
| language | English |
| last_indexed | 2024-03-12T03:56:53Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj.art-9c4b6378413149c19dccddacb8001d552023-09-03T11:53:45ZengIOP PublishingThe Astronomical Journal1538-38812023-01-01165626110.3847/1538-3881/acd342Warm Jupiters Beyond the Tidal Synchronization Limit may Exhibit a Wide Range of Secondary Eclipse DepthsEmily Rauscher0https://orcid.org/0000-0003-3963-9672Nicolas B. Cowan1https://orcid.org/0000-0001-6129-5699Rodrigo Luger2https://orcid.org/0000-0002-0296-3826Department of Astronomy, University of Michigan , 1085 S. University Avenue, Ann Arbor, MI 48109, USA ; erausche@umich.eduDepartment of Physics, McGill University , 3600 rue University, Montréal, QC, H3A 2T8, Canada; McGill Space Institute, 3550 rue University , Montréal, QC, H3A 2A7, CanadaCenter for Computational Astrophysics, Flatiron Institute , New York, NY, USAWith the JWST we can now characterize the atmospheres of longer-orbit planets, but this moves us into a regime where we cannot assume that tidal forces from the star have eroded the planets’ obliquities and synchronized their rotation rates. These rotation vectors may be tracers of formation and evolution histories and also enable a range of atmospheric circulation states. Here we delineate the orbital space over which tidal synchronization and alignment assumptions may no longer apply and present three-dimensional atmospheric models of a hypothetical warm Jupiter over a range of rotation rates and obliquities. We simulate the secondary eclipses of this planet for different possible viewing orientations and times during its orbital, seasonal cycle. We find that the eclipse depth can be strongly influenced by the rotation rate and obliquity through the timing of the eclipse relative to the planet’s seasonal cycle, and advise caution in attempting to derive properties such as albedo or day–night transport from this measurement. We predict that if warm Jupiters beyond the tidal limit have intrinsic diversity in their rotation vectors, then this will manifest itself as dispersion in their secondary eclipse depths. We explore eclipse mapping as a way to uniquely constrain the rotation vector of warm Jupiters but find that the associated signals are likely at the edge of the JWST performance. Nevertheless, as the JWST begins to measure the secondary eclipses of longer-orbital-period planets, we should expect to observe the consequences of a wider range of rotation states and circulation patterns.https://doi.org/10.3847/1538-3881/acd342Exoplanet atmospheresAtmospheric dynamicsExoplanetsExtrasolar gaseous planetsJames Webb Space TelescopeEclipses |
| spellingShingle | Emily Rauscher Nicolas B. Cowan Rodrigo Luger Warm Jupiters Beyond the Tidal Synchronization Limit may Exhibit a Wide Range of Secondary Eclipse Depths The Astronomical Journal Exoplanet atmospheres Atmospheric dynamics Exoplanets Extrasolar gaseous planets James Webb Space Telescope Eclipses |
| title | Warm Jupiters Beyond the Tidal Synchronization Limit may Exhibit a Wide Range of Secondary Eclipse Depths |
| title_full | Warm Jupiters Beyond the Tidal Synchronization Limit may Exhibit a Wide Range of Secondary Eclipse Depths |
| title_fullStr | Warm Jupiters Beyond the Tidal Synchronization Limit may Exhibit a Wide Range of Secondary Eclipse Depths |
| title_full_unstemmed | Warm Jupiters Beyond the Tidal Synchronization Limit may Exhibit a Wide Range of Secondary Eclipse Depths |
| title_short | Warm Jupiters Beyond the Tidal Synchronization Limit may Exhibit a Wide Range of Secondary Eclipse Depths |
| title_sort | warm jupiters beyond the tidal synchronization limit may exhibit a wide range of secondary eclipse depths |
| topic | Exoplanet atmospheres Atmospheric dynamics Exoplanets Extrasolar gaseous planets James Webb Space Telescope Eclipses |
| url | https://doi.org/10.3847/1538-3881/acd342 |
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