TOI-2196 b : rare planet in the hot Neptune desert transiting a G-type star
| Autor: | Carina M. Persson, Iskra Y. Georgieva, Davide Gandolfi, Lorena Acuna, Artem Aguichine, Alexandra Muresan, Eike Guenther, John Livingston, Karen A. Collins, Fei Dai, Malcolm Fridlund, Elisa Goffo, James S. Jenkins, Petr Kabáth, Judith Korth, Alan M. Levine, Luisa M. Serrano, José Vines, Oscar Barragan, Ilaria Carleo, Knicole D. Colon, William D. Cochran, Jessie L. Christiansen, Hans J. Deeg, Magali Deleuil, Diana Dragomir, Massimiliamo Esposito, Tianjun Gan, Sascha Grziwa, Artie P. Hatzes, Katharine Hesse, Keith Horne, Jon M. Jenkins, John F. Kielkopf, P. Klagyivik, Kristine W. F. Lam, David W. Latham, Rafa Luque, Jaume Orell-Miquel, Annelies Mortier, Olivier Mousis, Noria Narita, Hannah L. M. Osborne, Enric Palle, Riccardo Papini, George R. Ricker, Hendrik Schmerling, Sara Seager, Keivan G. Stassun, Vincent Van Eylen, Roland Vanderspek, Gavin Wang, Joshua N. Winn, Bill Wohler, Roberto Zambelli, Carl Ziegler |
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| Přispěvatelé: | University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
planets and satellites: detection
FOS: Physical sciences techniques: photometric techniques: radial velocities radial velocity [Techniques] QB Astronomy QC Planets and satellites - composition QB Earth and Planetary Astrophysics (astro-ph.EP) MCC [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] Astrophysics - earth and planetary astrophysics photometric [Techniques] planets and satellites: composition 500 Naturwissenschaften und Mathematik::520 Astronomie::520 Astronomie und zugeordnete Wissenschaften Astronomy and Astrophysics 3rd-DAS Planets and satellites - individual - TOI-2196 Planetary systems detection [Planets and satellites] QC Physics [SDU]Sciences of the Universe [physics] Space and Planetary Science planets and satellites: individual: TOI-2196 Techniques - radial velocities composition [Planets and satellites] Techniques - photometric individual: TOI-2196 [Planets and satellites] Planets and satellites - detection |
| Zdroj: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, 2022, 666, ⟨10.1051/0004-6361/202244118⟩ Astronomy & Astrophysics, 666:A184 |
| ISSN: | 0004-6361 |
| Popis: | Highly irradiated planets in the hot Neptune desert are usually either small (R < 2 Rearth) and rocky or they are gas giants with radii of >1 Rjup. Here, we report on the intermediate-sized planet TOI-2196 on a 1.2 day orbit around a G-type star discovered by TESS in sector 27. We collected 42 radial velocity measurements with the HARPS spectrograph to determine the mass. The radius of TOI-2196 b is 3.51 +/- 0.15 Rearth, which, combined with the mass of 26.0 +/- 1.3 Mearth, results in a bulk density of 3.31+0.51-0.43 g/cm3. Hence, the radius implies that this planet is a sub-Neptune, although the density is twice than that of Neptune. A significant trend in the HARPS radial velocities points to the presence of a distant companion with a lower limit on the period and mass of 220 days and 0.65 Mjup, respectively, assuming zero eccentricity. The short period of planet b implies a high equilibrium temperature of 1860 +/- 20 K, for zero albedo and isotropic emission. This places the planet in the hot Neptune desert, joining a group of very few planets in this parameter space discovered in recent years. These planets suggest that the hot Neptune desert may be divided in two parts for planets with equilibrium temperatures of > 1800 K: a hot sub-Neptune desert devoid of planets with radii of 1.8-3 Rearth and a sub-Jovian desert for radii of 5-12 Rearth. More planets in this parameter space are needed to further investigate this finding. Planetary interior structure models of TOI-2196 b are consistent with a H/He atmosphere mass fraction between 0.4 % and 3 %, with a mean value of 0.7 % on top of a rocky interior. We estimated the amount of mass this planet might have lost at a young age, and we find that while the mass loss could have been significant, the planet had not changed in terms of character: it was born as a small volatile-rich planet, and it remains one at present. 17 pages, 15 figures, 7 tables, accepted 11 July 2022 for publication in Astronomy & Astrophysics |
| Databáze: | OpenAIRE |
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