High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters
High-eccentricity migration is a likely formation mechanism for many observed hot Jupiters, particularly those with a large misalignment between the stellar spin axis and orbital angular momentum axis of the planet. In one version of high-eccentricity migration, an inclined stellar companion excites...
| 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 Astrophysical Journal Letters |
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| Online Access: | https://doi.org/10.3847/2041-8213/acaea6 |
| _version_ | 1797695796246740992 |
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| author | Michelle Vick Yubo Su Dong Lai |
| author_facet | Michelle Vick Yubo Su Dong Lai |
| author_sort | Michelle Vick |
| collection | DOAJ |
| description | High-eccentricity migration is a likely formation mechanism for many observed hot Jupiters, particularly those with a large misalignment between the stellar spin axis and orbital angular momentum axis of the planet. In one version of high-eccentricity migration, an inclined stellar companion excites von Zeipel–Lidov–Kozai (ZLK) eccentricity oscillations of a cold Jupiter, and tidal dissipation causes the planet’s orbit to shrink and circularize. Throughout this process, the stellar spin can evolve chaotically, resulting in highly misaligned hot Jupiters (HJs). Previous population studies of this migration mechanism have assumed that the stellar spin is aligned with the planetary orbital angular momentum when the companion begins to induce ZLK oscillations. However, in the presence of a binary companion, the star’s obliquity may be significantly excited during the dissipation of its protoplanetary disk. We calculate the stellar obliquities produced in the protoplanetary disk phase and use these to perform an updated population synthesis of ZLK-driven high-eccentricity migration with an F-type host star. We find that the resulting obliquity distribution of HJ systems is predominantly retrograde with a broad peak near 90°. The distribution we obtain has intriguing similarities to the recently observed preponderance of perpendicular planets close to their host stars. |
| first_indexed | 2024-03-12T03:17:21Z |
| format | Article |
| id | doaj.art-be5d045be54948e38472e19b9694cc45 |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-03-12T03:17:21Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-be5d045be54948e38472e19b9694cc452023-09-03T14:08:27ZengIOP PublishingThe Astrophysical Journal Letters2041-82052023-01-019432L1310.3847/2041-8213/acaea6High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot JupitersMichelle Vick0https://orcid.org/0000-0002-3752-3038Yubo Su1https://orcid.org/0000-0001-8283-3425Dong Lai2https://orcid.org/0000-0002-1934-6250Center for Interdisciplinary Exploration & Research in Astrophysics (CIERA) Northwestern University , Evanston, IL 60208, USA michelle.birch@northwestern.eduDepartment of Astrophysical Sciences Princeton University , Princeton, NJ 08544, USACornell Center for Astrophysics and Planetary Science, Department of Astronomy Cornell University , Ithaca, NY 14853, USAHigh-eccentricity migration is a likely formation mechanism for many observed hot Jupiters, particularly those with a large misalignment between the stellar spin axis and orbital angular momentum axis of the planet. In one version of high-eccentricity migration, an inclined stellar companion excites von Zeipel–Lidov–Kozai (ZLK) eccentricity oscillations of a cold Jupiter, and tidal dissipation causes the planet’s orbit to shrink and circularize. Throughout this process, the stellar spin can evolve chaotically, resulting in highly misaligned hot Jupiters (HJs). Previous population studies of this migration mechanism have assumed that the stellar spin is aligned with the planetary orbital angular momentum when the companion begins to induce ZLK oscillations. However, in the presence of a binary companion, the star’s obliquity may be significantly excited during the dissipation of its protoplanetary disk. We calculate the stellar obliquities produced in the protoplanetary disk phase and use these to perform an updated population synthesis of ZLK-driven high-eccentricity migration with an F-type host star. We find that the resulting obliquity distribution of HJ systems is predominantly retrograde with a broad peak near 90°. The distribution we obtain has intriguing similarities to the recently observed preponderance of perpendicular planets close to their host stars.https://doi.org/10.3847/2041-8213/acaea6Planetary-disk interactionsExoplanet dynamicsExoplanet tidesStar-planet interactionsHot Jupiters |
| spellingShingle | Michelle Vick Yubo Su Dong Lai High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters The Astrophysical Journal Letters Planetary-disk interactions Exoplanet dynamics Exoplanet tides Star-planet interactions Hot Jupiters |
| title | High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters |
| title_full | High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters |
| title_fullStr | High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters |
| title_full_unstemmed | High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters |
| title_short | High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters |
| title_sort | high eccentricity migration with disk induced spin orbit misalignment a preference for perpendicular hot jupiters |
| topic | Planetary-disk interactions Exoplanet dynamics Exoplanet tides Star-planet interactions Hot Jupiters |
| url | https://doi.org/10.3847/2041-8213/acaea6 |
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