Tidal Dissipation Regimes among the Short-period Exoplanets
The efficiency of tidal dissipation provides a zeroth-order link to a planet’s physical properties. For super-Earth and sub-Neptune planets in the range R _⊕ ≲ R _p ≲ 4 R _⊕ , particularly efficient dissipation (i.e., low tidal quality factors) may signify terrestrial-like planets capable of maintai...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2023-01-01
|
| Series: | The Astrophysical Journal Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/2041-8213/ad0843 |
| _version_ | 1827643429342937088 |
|---|---|
| author | Emma M. Louden Gregory P. Laughlin Sarah C. Millholland |
| author_facet | Emma M. Louden Gregory P. Laughlin Sarah C. Millholland |
| author_sort | Emma M. Louden |
| collection | DOAJ |
| description | The efficiency of tidal dissipation provides a zeroth-order link to a planet’s physical properties. For super-Earth and sub-Neptune planets in the range R _⊕ ≲ R _p ≲ 4 R _⊕ , particularly efficient dissipation (i.e., low tidal quality factors) may signify terrestrial-like planets capable of maintaining rigid crustal features. Here, we explore global constraints on planetary tidal quality factors using a population of planets in multiple-planet systems whose orbital and physical properties indicate susceptibility to capture into secular spin–orbit resonances. Planets participating in secular spin–orbit resonance can maintain large axial tilts and significantly enhanced heating from obliquity tides. When obliquity tides are sufficiently strong, planets in low-order mean-motion resonances can experience resonant repulsion (period ratio increase). The observed distribution of period ratios among transiting planet pairs may thus depend nontrivially on the underlying planetary structures. We model the action of resonant repulsion and demonstrate that the observed distribution of period ratios near the 2:1 and 3:2 commensurabilities implies Q values spanning from Q ≈ 10 ^1 –10 ^7 and peaking at Q ≈ 10 ^6 . This range includes the expected range in which super-Earth and sub-Neptune planets dissipate ( Q ≈ 10 ^3 –10 ^4 ). This work serves as a proof of concept for a method of assessing the presence of two dissipation regimes, and we estimate the number of additional multitransiting planetary systems needed to place any bimodality in the distribution on a strong statistical footing. |
| first_indexed | 2024-03-09T17:54:12Z |
| format | Article |
| id | doaj.art-64cc60bc70aa4906925b63e2ff58f582 |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-03-09T17:54:12Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-64cc60bc70aa4906925b63e2ff58f5822023-11-24T10:29:07ZengIOP PublishingThe Astrophysical Journal Letters2041-82052023-01-019582L2110.3847/2041-8213/ad0843Tidal Dissipation Regimes among the Short-period ExoplanetsEmma M. Louden0https://orcid.org/0000-0003-3179-5320Gregory P. Laughlin1https://orcid.org/0000-0002-3253-2621Sarah C. Millholland2https://orcid.org/0000-0003-3130-2282Yale University , 219 Prospect St., New Haven, CT 06511, USA ; emma.louden@yale.eduYale University , 219 Prospect St., New Haven, CT 06511, USA ; emma.louden@yale.eduMIT Kavli Institute for Astrophysics and Space Research , Massachusetts Institute of Technology, Cambridge, MA 02139, USAThe efficiency of tidal dissipation provides a zeroth-order link to a planet’s physical properties. For super-Earth and sub-Neptune planets in the range R _⊕ ≲ R _p ≲ 4 R _⊕ , particularly efficient dissipation (i.e., low tidal quality factors) may signify terrestrial-like planets capable of maintaining rigid crustal features. Here, we explore global constraints on planetary tidal quality factors using a population of planets in multiple-planet systems whose orbital and physical properties indicate susceptibility to capture into secular spin–orbit resonances. Planets participating in secular spin–orbit resonance can maintain large axial tilts and significantly enhanced heating from obliquity tides. When obliquity tides are sufficiently strong, planets in low-order mean-motion resonances can experience resonant repulsion (period ratio increase). The observed distribution of period ratios among transiting planet pairs may thus depend nontrivially on the underlying planetary structures. We model the action of resonant repulsion and demonstrate that the observed distribution of period ratios near the 2:1 and 3:2 commensurabilities implies Q values spanning from Q ≈ 10 ^1 –10 ^7 and peaking at Q ≈ 10 ^6 . This range includes the expected range in which super-Earth and sub-Neptune planets dissipate ( Q ≈ 10 ^3 –10 ^4 ). This work serves as a proof of concept for a method of assessing the presence of two dissipation regimes, and we estimate the number of additional multitransiting planetary systems needed to place any bimodality in the distribution on a strong statistical footing.https://doi.org/10.3847/2041-8213/ad0843Exoplanet tidesExoplanet structureExoplanet dynamics |
| spellingShingle | Emma M. Louden Gregory P. Laughlin Sarah C. Millholland Tidal Dissipation Regimes among the Short-period Exoplanets The Astrophysical Journal Letters Exoplanet tides Exoplanet structure Exoplanet dynamics |
| title | Tidal Dissipation Regimes among the Short-period Exoplanets |
| title_full | Tidal Dissipation Regimes among the Short-period Exoplanets |
| title_fullStr | Tidal Dissipation Regimes among the Short-period Exoplanets |
| title_full_unstemmed | Tidal Dissipation Regimes among the Short-period Exoplanets |
| title_short | Tidal Dissipation Regimes among the Short-period Exoplanets |
| title_sort | tidal dissipation regimes among the short period exoplanets |
| topic | Exoplanet tides Exoplanet structure Exoplanet dynamics |
| url | https://doi.org/10.3847/2041-8213/ad0843 |
| work_keys_str_mv | AT emmamlouden tidaldissipationregimesamongtheshortperiodexoplanets AT gregoryplaughlin tidaldissipationregimesamongtheshortperiodexoplanets AT sarahcmillholland tidaldissipationregimesamongtheshortperiodexoplanets |