UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

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

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. Green open access

[thumbnail of Van Eylen_staa2077.pdf]
Preview
Text
Van Eylen_staa2077.pdf - Published Version

Download (5MB) | Preview

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
Downloads since deposit
34Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item