A tidally detached super Neptune on a strongly misaligned retrograde orbit
Fuente:
arXiv
Salvato in:
| Autori principali: | , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2026
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866911675047739392 |
|---|---|
| author | Mantovan, G. Malavolta, L. Lanza, A. F. Marzari, F. Naponiello, L. Biazzo, K. Cosentino, R. D'Arpa, M. C. Desidera, S. Guilluy, G. Nardiello, D. Sozzetti, A. Vissapragada, S. Aloisi, R. Benatti, S. Borsato, L. Claudi, R. Jenkins, S. Nascimbeni, V. Piotto, G. Zingales, T. |
| author_facet | Mantovan, G. Malavolta, L. Lanza, A. F. Marzari, F. Naponiello, L. Biazzo, K. Cosentino, R. D'Arpa, M. C. Desidera, S. Guilluy, G. Nardiello, D. Sozzetti, A. Vissapragada, S. Aloisi, R. Benatti, S. Borsato, L. Claudi, R. Jenkins, S. Nascimbeni, V. Piotto, G. Zingales, T. |
| contents | The obliquity between a planet's orbital axis and its host star's spin axis provides crucial insights into planetary formation and migration. Planets with scaled semi-major axes ($a/R_\star$) large enough to be unaffected by tidal alterations ("tidally detached"), offer a unique opportunity to study the original obliquity in which the system formed. We therefore observed TOI-1710 b ($a/R_\star \approx 36$) in-transit using HARPS-N + GIANO-B, collecting high-precision radial velocities to measure the Rossiter-McLaughlin (RM) effect. Spectral analysis of the H$α$ and HeI triple lines was also pursued to evaluate atmospheric photoevaporation. Using our knowledge of the star rotation period ($21.5 \pm 0.2$ d), we estimated a true obliquity of $ψ= 149 ^{+11}_{-10}$ deg, which indicates a retrograde motion and places TOI-1710 b among the most misaligned systems -- and the only one known orbiting a cool star in retrograde motion. The strong misalignment favours a high-eccentricity migration (HEM) origin for this low-density super-Neptune planet in the savanna region, challenging previous findings that claimed a minor role of HEM in this period-radius(-density) domain. Moreover, the strong misalignment and lack of a detected close stellar companion suggests a purely planetary post-migration misalignment, likely due to planet-planet scattering followed by planet-planet Kozai-Lidov oscillations and tidal circularisation. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2604_19179 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | A tidally detached super Neptune on a strongly misaligned retrograde orbit Mantovan, G. Malavolta, L. Lanza, A. F. Marzari, F. Naponiello, L. Biazzo, K. Cosentino, R. D'Arpa, M. C. Desidera, S. Guilluy, G. Nardiello, D. Sozzetti, A. Vissapragada, S. Aloisi, R. Benatti, S. Borsato, L. Claudi, R. Jenkins, S. Nascimbeni, V. Piotto, G. Zingales, T. Earth and Planetary Astrophysics The obliquity between a planet's orbital axis and its host star's spin axis provides crucial insights into planetary formation and migration. Planets with scaled semi-major axes ($a/R_\star$) large enough to be unaffected by tidal alterations ("tidally detached"), offer a unique opportunity to study the original obliquity in which the system formed. We therefore observed TOI-1710 b ($a/R_\star \approx 36$) in-transit using HARPS-N + GIANO-B, collecting high-precision radial velocities to measure the Rossiter-McLaughlin (RM) effect. Spectral analysis of the H$α$ and HeI triple lines was also pursued to evaluate atmospheric photoevaporation. Using our knowledge of the star rotation period ($21.5 \pm 0.2$ d), we estimated a true obliquity of $ψ= 149 ^{+11}_{-10}$ deg, which indicates a retrograde motion and places TOI-1710 b among the most misaligned systems -- and the only one known orbiting a cool star in retrograde motion. The strong misalignment favours a high-eccentricity migration (HEM) origin for this low-density super-Neptune planet in the savanna region, challenging previous findings that claimed a minor role of HEM in this period-radius(-density) domain. Moreover, the strong misalignment and lack of a detected close stellar companion suggests a purely planetary post-migration misalignment, likely due to planet-planet scattering followed by planet-planet Kozai-Lidov oscillations and tidal circularisation. |
| title | A tidally detached super Neptune on a strongly misaligned retrograde orbit |
| topic | Earth and Planetary Astrophysics |
| url | https://arxiv.org/abs/2604.19179 |