K2-280 b - a low density warm sub-Saturn around a mildly evolved star

Nowak, Grzegorz; Palle, Enric; Gandolfi, Davide; Deeg, Hans J.; Hirano, Teruyuki; Barragán, Oscar; Kuzuhara, Masayuki; Dai, Fei; Luque, Rafael; Persson, Carina M.; Fridlund, Malcolm; Johnson, Marshall C.; Korth, Judith; Livingston, John H.; Grziwa, Sascha; Mathur, Savita; Hatzes, Artie P.; Prieto-Arranz, Jorge; Nespral, David; Hidalgo, Diego; Hjorth, Maria; Albrecht, Simon; Van Eylen, Vincent; Lam, Kristine W. F.; Cochran, William D.; Esposito, Massimiliano; Csizmadia, Szilárd; Guenther, Eike W.; Kabath, Petr; Blay, Pere; Brahm, Rafael; Jordán, Andrés; Espinoza, Néstor; Rojas, Felipe; Casasayas Barris, Núria; Rodler, Florian; Alonso Sobrino, Roi; Cabrera, Juan; Carleo, Ilaria; Chaushev, Alexander; de Leon, Jerome; Eigmüller, Philipp; Endl, Michael; Erikson, Anders; Fukui, Akihiko; Georgieva, Iskra; González-Cuesta, Lucía; Knudstrup, Emil; Lund, Mikkel N.; Montañes Rodríguez, Pilar; Murgas, Felipe; Narita, Norio; Niraula, Prajwal; Pätzold, Martin; Rauer, Heike; Redfield, Seth; Ribas, Ignasi; Skarka, Marek; Smith, Alexis M. S.; Subjak, Jano
Bibliographical reference

Monthly Notices of the Royal Astronomical Society

Advertised on:
7
2020
Number of authors
60
IAC number of authors
14
Citations
4
Refereed citations
4
Description
We present an independent discovery and detailed characterization of K2-280 b, a transiting low density warm sub-Saturn in a 19.9-d moderately eccentric orbit (e = $0.35_{-0.04}^{+0.05}$ ) from K2 campaign 7. A joint analysis of high precision HARPS, HARPS-N, and FIES radial velocity measurements and K2 photometric data indicates that K2-280 b has a radius of Rb = 7.50 ± 0.44 R⊕ and a mass of Mb = 37.1 ± 5.6 M⊕, yielding a mean density of ρb = $0.48 _{ - 0.10 } ^ { + 0.13 }$ ${\rm g\, cm^{-3}}$. The host star is a mildly evolved G7 star with an effective temperature of Teff = 5500 ± 100 K, a surface gravity of $\log \, g_{\star }$ = 4.21 ± 0.05 (cgs), and an iron abundance of [Fe/H] = ${0.33}\, {\pm }\, {0.08}$ dex, and with an inferred mass of M⋆ = 1.03 ± 0.03 M☉ and a radius of R⋆ = 1.28 ± 0.07 R☉. We discuss the importance of K2-280 b for testing formation scenarios of sub-Saturn planets and the current sample of this intriguing group of planets that are absent in the Solar system.
Related projects
Helio and Asteroseismology
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur
Projects' name image
Exoplanets and Astrobiology
The search for life in the universe has been driven by recent discoveries of planets around other stars (known as exoplanets), becoming one of the most active fields in modern astrophysics. The growing number of new exoplanets discovered in recent years and the recent advance on the study of their atmospheres are not only providing new valuable
Enric
Pallé Bago