Role of Planetary Radius on Atmospheric Escape of Rocky Exoplanets
Large-scale characterization of exoplanetary atmospheres is on the horizon, thereby making it possible in the future to extract their statistical properties. In this context, by using a well-validated model in the solar system, we carry out 3D magnetohydrodynamic simulations to compute nonthermal at...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/2041-8213/ad27d8 |
| _version_ | 1797299300230758400 |
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| author | Laura Chin Chuanfei Dong Manasvi Lingam |
| author_facet | Laura Chin Chuanfei Dong Manasvi Lingam |
| author_sort | Laura Chin |
| collection | DOAJ |
| description | Large-scale characterization of exoplanetary atmospheres is on the horizon, thereby making it possible in the future to extract their statistical properties. In this context, by using a well-validated model in the solar system, we carry out 3D magnetohydrodynamic simulations to compute nonthermal atmospheric ion escape rates of unmagnetized rocky exoplanets as a function of their radius based on fixed stellar radiation and wind conditions. We find that the atmospheric escape rate is, unexpectedly and strikingly, a nonmonotonic function of the planetary radius R and that it evinces a maximum at R ∼ 0.7 R _⊕ . This novel nonmonotonic behavior may arise from an intricate trade-off between the cross-sectional area of a planet (which increases with size, boosting escape rates) and its associated escape velocity (which also increases with size but diminishes escape rates). Our results could guide forthcoming observations because worlds with certain values of R (such as R ∼ 0.7 R _⊕ ) might exhibit comparatively higher escape rates when all other factors are constant. |
| first_indexed | 2024-03-07T22:48:36Z |
| format | Article |
| id | doaj.art-744ec579e32f4f46a58a01ac3715ca85 |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-03-07T22:48:36Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-744ec579e32f4f46a58a01ac3715ca852024-02-23T12:40:14ZengIOP PublishingThe Astrophysical Journal Letters2041-82052024-01-019631L2010.3847/2041-8213/ad27d8Role of Planetary Radius on Atmospheric Escape of Rocky ExoplanetsLaura Chin0https://orcid.org/0009-0006-7877-1835Chuanfei Dong1https://orcid.org/0000-0002-8990-094XManasvi Lingam2https://orcid.org/0000-0002-2685-9417Department of Astronomy, Boston University , Boston, MA 02215, USA ; dcfy@bu.eduDepartment of Astronomy, Boston University , Boston, MA 02215, USA ; dcfy@bu.eduDepartment of Aerospace, Physics and Space Sciences, Florida Institute of Technology , Melbourne, FL 32901, USA ; mlingam@fit.edu; Department of Physics, The University of Texas at Austin , Austin, TX 78712, USALarge-scale characterization of exoplanetary atmospheres is on the horizon, thereby making it possible in the future to extract their statistical properties. In this context, by using a well-validated model in the solar system, we carry out 3D magnetohydrodynamic simulations to compute nonthermal atmospheric ion escape rates of unmagnetized rocky exoplanets as a function of their radius based on fixed stellar radiation and wind conditions. We find that the atmospheric escape rate is, unexpectedly and strikingly, a nonmonotonic function of the planetary radius R and that it evinces a maximum at R ∼ 0.7 R _⊕ . This novel nonmonotonic behavior may arise from an intricate trade-off between the cross-sectional area of a planet (which increases with size, boosting escape rates) and its associated escape velocity (which also increases with size but diminishes escape rates). Our results could guide forthcoming observations because worlds with certain values of R (such as R ∼ 0.7 R _⊕ ) might exhibit comparatively higher escape rates when all other factors are constant.https://doi.org/10.3847/2041-8213/ad27d8AstrobiologyMagnetohydrodynamical simulationsHabitable planetsExoplanet atmospheresStellar winds |
| spellingShingle | Laura Chin Chuanfei Dong Manasvi Lingam Role of Planetary Radius on Atmospheric Escape of Rocky Exoplanets The Astrophysical Journal Letters Astrobiology Magnetohydrodynamical simulations Habitable planets Exoplanet atmospheres Stellar winds |
| title | Role of Planetary Radius on Atmospheric Escape of Rocky Exoplanets |
| title_full | Role of Planetary Radius on Atmospheric Escape of Rocky Exoplanets |
| title_fullStr | Role of Planetary Radius on Atmospheric Escape of Rocky Exoplanets |
| title_full_unstemmed | Role of Planetary Radius on Atmospheric Escape of Rocky Exoplanets |
| title_short | Role of Planetary Radius on Atmospheric Escape of Rocky Exoplanets |
| title_sort | role of planetary radius on atmospheric escape of rocky exoplanets |
| topic | Astrobiology Magnetohydrodynamical simulations Habitable planets Exoplanet atmospheres Stellar winds |
| url | https://doi.org/10.3847/2041-8213/ad27d8 |
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