Nowak, G;
Palle, E;
Gandolfi, D;
Deeg, HJ;
Hirano, T;
Barragán, O;
Kuzuhara, M;
... Subjak, J; + view all
(2020)
K2-280b -- a low density warm sub-Saturn around a mildly evolved star.
Monthly Notices of the Royal Astronomical Society
, 497
(4)
pp. 4423-4435.
10.1093/mnras/staa2077.
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Abstract
We present an independent discovery and detailed characterisation of K2-280b, a transiting low density warm sub-Saturn in a 19.9-day 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 K2-280b has a radius of R_b = 7.50 +/- 0.44 R_Earth and a mass of M_b = 37.1 +/- 5.6 M_Earth, yielding a mean density of 0.48_{-0.10}^{+0.13} g/cm^3. The host star is a mildly evolved G7 star with an effective temperature of T_{eff} = 5500 +/- 100 K, a surface gravity of log(g) = 4.21 +/- 0.05 (cgs), and an iron abundance of [Fe/H] = 0.33 +/- 0.08 dex, and with an inferred mass of M_star = 1.03 +/- 0.03 M_sun and a radius of R_star = 1.28 +/- 0.07 R_sun. We discuss the importance of K2-280b 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.
| Type: | Article |
|---|---|
| Title: | K2-280b -- a low density warm sub-Saturn around a mildly evolved star |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/staa2077 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/staa2077 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | techniques: photometric, techniques: radial velocities, techniques: spectroscopic, planets and satellites: detection, stars: individual: (EPIC 216494238, K2-280) |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10107009 |
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