Detection of an Atmospheric Outflow from the Young Hot Saturn TOI-1268b
Photoevaporative mass-loss rates are expected to be highest when planets are young and the host star is more active, but to date there have been relatively few measurements of mass-loss rates for young gas giant exoplanets. In this study we measure the present-day atmospheric mass-loss rate of TOI-1...
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IOP Publishing
2024-01-01
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| Series: | The Astronomical Journal |
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| Online Access: | https://doi.org/10.3847/1538-3881/ad34b6 |
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| author | Jorge Pérez-González Michael Greklek-McKeon Shreyas Vissapragada Morgan Saidel Heather A. Knutson Dion Linssen Antonija Oklopčić |
| author_facet | Jorge Pérez-González Michael Greklek-McKeon Shreyas Vissapragada Morgan Saidel Heather A. Knutson Dion Linssen Antonija Oklopčić |
| author_sort | Jorge Pérez-González |
| collection | DOAJ |
| description | Photoevaporative mass-loss rates are expected to be highest when planets are young and the host star is more active, but to date there have been relatively few measurements of mass-loss rates for young gas giant exoplanets. In this study we measure the present-day atmospheric mass-loss rate of TOI-1268b, a young (110–380 Myr) and low density (0.71 ${}_{-0.13}^{+0.17}$ g cm ^−3 ) hot Saturn located near the upper edge of the Neptune desert. We use Palomar/WIRC to search for excess absorption in the 1083 nm helium triplet during two transits of TOI-1268b. We find that it has a larger transit depth ( ${0.285}_{-0.050}^{+0.048} \% $ excess) in the helium bandpass than in the TESS observations, and convert this excess absorption into a mass-loss rate by modeling the outflow as a Parker wind. Our results indicate that this planet is losing mass at a rate of $\mathrm{log}\dot{M}=10.2\pm 0.3$ g s ^−1 and has a thermosphere temperature of ${6900}_{-1200}^{+1800}$ K. This corresponds to a predicted atmospheric lifetime much larger than 10 Gyr. Our result suggests that photoevaporation is weak in gas giant exoplanets even at early ages. |
| format | Article |
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| institution | Kabale University |
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| language | English |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
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| series | The Astronomical Journal |
| spelling | doaj-art-5f301d5bedce460f988e50d96c640f462024-11-12T10:57:07ZengIOP PublishingThe Astronomical Journal1538-38812024-01-01167521410.3847/1538-3881/ad34b6Detection of an Atmospheric Outflow from the Young Hot Saturn TOI-1268bJorge Pérez-González0https://orcid.org/0000-0001-7144-589XMichael Greklek-McKeon1https://orcid.org/0000-0002-0371-1647Shreyas Vissapragada2https://orcid.org/0000-0003-2527-1475Morgan Saidel3https://orcid.org/0000-0001-9518-9691Heather A. Knutson4https://orcid.org/0000-0002-5375-4725Dion Linssen5https://orcid.org/0000-0001-6025-6663Antonija Oklopčić6https://orcid.org/0000-0002-9584-6476Department of Physics and Astronomy, University College London ,Gower Street, WC1E 6BT London, UKDivision of Geological and Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USACenter for Astrophysics∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USADivision of Geological and Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USADivision of Geological and Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USAAnton Pannekoek Institute of Astronomy, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The NetherlandsAnton Pannekoek Institute of Astronomy, University of Amsterdam , Science Park 904, 1098 XH Amsterdam, The NetherlandsPhotoevaporative mass-loss rates are expected to be highest when planets are young and the host star is more active, but to date there have been relatively few measurements of mass-loss rates for young gas giant exoplanets. In this study we measure the present-day atmospheric mass-loss rate of TOI-1268b, a young (110–380 Myr) and low density (0.71 ${}_{-0.13}^{+0.17}$ g cm ^−3 ) hot Saturn located near the upper edge of the Neptune desert. We use Palomar/WIRC to search for excess absorption in the 1083 nm helium triplet during two transits of TOI-1268b. We find that it has a larger transit depth ( ${0.285}_{-0.050}^{+0.048} \% $ excess) in the helium bandpass than in the TESS observations, and convert this excess absorption into a mass-loss rate by modeling the outflow as a Parker wind. Our results indicate that this planet is losing mass at a rate of $\mathrm{log}\dot{M}=10.2\pm 0.3$ g s ^−1 and has a thermosphere temperature of ${6900}_{-1200}^{+1800}$ K. This corresponds to a predicted atmospheric lifetime much larger than 10 Gyr. Our result suggests that photoevaporation is weak in gas giant exoplanets even at early ages.https://doi.org/10.3847/1538-3881/ad34b6Exoplanet atmospheresNarrow band photometry |
| spellingShingle | Jorge Pérez-González Michael Greklek-McKeon Shreyas Vissapragada Morgan Saidel Heather A. Knutson Dion Linssen Antonija Oklopčić Detection of an Atmospheric Outflow from the Young Hot Saturn TOI-1268b The Astronomical Journal Exoplanet atmospheres Narrow band photometry |
| title | Detection of an Atmospheric Outflow from the Young Hot Saturn TOI-1268b |
| title_full | Detection of an Atmospheric Outflow from the Young Hot Saturn TOI-1268b |
| title_fullStr | Detection of an Atmospheric Outflow from the Young Hot Saturn TOI-1268b |
| title_full_unstemmed | Detection of an Atmospheric Outflow from the Young Hot Saturn TOI-1268b |
| title_short | Detection of an Atmospheric Outflow from the Young Hot Saturn TOI-1268b |
| title_sort | detection of an atmospheric outflow from the young hot saturn toi 1268b |
| topic | Exoplanet atmospheres Narrow band photometry |
| url | https://doi.org/10.3847/1538-3881/ad34b6 |
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