GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation
We report the detection of GJ 3090 b (TOI-177.01), a mini-Neptune on a 2.9-day orbit transiting a bright (K = 7.3 mag) M2 dwarf located at 22 pc. The planet was identified by the Transiting Exoplanet Survey Satellite and was confirmed with the High Accuracy Radial velocity Planet Searcher radial v...
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| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
EDP Sciences
2023
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| Online Access: | https://hdl.handle.net/1721.1/148414 |
| _version_ | 1811068291270049792 |
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| author | Seager, Sara |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Seager, Sara |
| author_sort | Seager, Sara |
| collection | MIT |
| description | We report the detection of GJ 3090 b (TOI-177.01), a mini-Neptune on a 2.9-day orbit transiting a bright (K = 7.3 mag) M2 dwarf
located at 22 pc. The planet was identified by the Transiting Exoplanet Survey Satellite and was confirmed with the High Accuracy
Radial velocity Planet Searcher radial velocities. Seeing-limited photometry and speckle imaging rule out nearby eclipsing binaries. Additional transits were observed with the LCOGT, Spitzer, and ExTrA telescopes. We characterise the star to have a mass of
0.519 ± 0.013 M and a radius of 0.516 ± 0.016 R . We modelled the transit light curves and radial velocity measurements and obtained
a planetary mass of 3.34 ± 0.72 ME, a radius of 2.13 ± 0.11 RE, and a mean density of 1.89+0.52
−0.45 g cm−3
. The low density of the planet
implies the presence of volatiles, and its radius and insolation place it immediately above the radius valley at the lower end of the
mini-Neptune cluster. A coupled atmospheric and dynamical evolution analysis of the planet is inconsistent with a pure H–He atmosphere and favours a heavy mean molecular weight atmosphere. The transmission spectroscopy metric of 221+66
−46 means that GJ 3090 b
is the second or third most favorable mini-Neptune after GJ 1214 b whose atmosphere may be characterised. At almost half the mass
of GJ 1214 b, GJ 3090 b is an excellent probe of the edge of the transition between super-Earths and mini-Neptunes. We identify an
additional signal in the radial velocity data that we attribute to a planet candidate with an orbital period of 13 days and a mass of
17.1+8.9
−3.2 ME, whose transits are not detected. |
| first_indexed | 2024-09-23T07:54:05Z |
| format | Article |
| id | mit-1721.1/148414 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T07:54:05Z |
| publishDate | 2023 |
| publisher | EDP Sciences |
| record_format | dspace |
| spelling | mit-1721.1/1484142023-03-09T03:52:31Z GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation Seager, Sara Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences We report the detection of GJ 3090 b (TOI-177.01), a mini-Neptune on a 2.9-day orbit transiting a bright (K = 7.3 mag) M2 dwarf located at 22 pc. The planet was identified by the Transiting Exoplanet Survey Satellite and was confirmed with the High Accuracy Radial velocity Planet Searcher radial velocities. Seeing-limited photometry and speckle imaging rule out nearby eclipsing binaries. Additional transits were observed with the LCOGT, Spitzer, and ExTrA telescopes. We characterise the star to have a mass of 0.519 ± 0.013 M and a radius of 0.516 ± 0.016 R . We modelled the transit light curves and radial velocity measurements and obtained a planetary mass of 3.34 ± 0.72 ME, a radius of 2.13 ± 0.11 RE, and a mean density of 1.89+0.52 −0.45 g cm−3 . The low density of the planet implies the presence of volatiles, and its radius and insolation place it immediately above the radius valley at the lower end of the mini-Neptune cluster. A coupled atmospheric and dynamical evolution analysis of the planet is inconsistent with a pure H–He atmosphere and favours a heavy mean molecular weight atmosphere. The transmission spectroscopy metric of 221+66 −46 means that GJ 3090 b is the second or third most favorable mini-Neptune after GJ 1214 b whose atmosphere may be characterised. At almost half the mass of GJ 1214 b, GJ 3090 b is an excellent probe of the edge of the transition between super-Earths and mini-Neptunes. We identify an additional signal in the radial velocity data that we attribute to a planet candidate with an orbital period of 13 days and a mass of 17.1+8.9 −3.2 ME, whose transits are not detected. 2023-03-08T16:07:14Z 2023-03-08T16:07:14Z 2022 2023-03-08T15:54:55Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/148414 Seager, Sara. 2022. "GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation." Astronomy and Astrophysics, 665. en 10.1051/0004-6361/202243975 Astronomy and Astrophysics Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf EDP Sciences EDP Sciences |
| spellingShingle | Seager, Sara GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation |
| title | GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation |
| title_full | GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation |
| title_fullStr | GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation |
| title_full_unstemmed | GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation |
| title_short | GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation |
| title_sort | gj 3090 b one of the most favourable mini neptune for atmospheric characterisation |
| url | https://hdl.handle.net/1721.1/148414 |
| work_keys_str_mv | AT seagersara gj3090boneofthemostfavourableminineptuneforatmosphericcharacterisation |