Radial velocity confirmation of K2-100b: a young, highly irradiated, and low-density transiting hot Neptune

Journal
Date Issued
2019
Author(s)
Barragán, O.
•
Aigrain, S.
•
Kubyshkina, D.
•
Gandolfi, D.
•
Livingston, J.
•
Fridlund, M. C. V.
•
Fossati, L.
•
Korth, J.
•
Parviainen, H.
•
•
Palle, E.
•
Deeg, H. J.
•
Nowak, G.
•
Rajpaul, V. M.
•
Zicher, N.
•
Antoniciello, G.
•
Narita, N.
•
Albrecht, S.
•
•
Cabrera, J.
•
Cochran, W. D.
•
de Leon, J.
•
Eigmüller, Ph
•
Fukui, A.
•
Granata, V.
•
Grziwa, S.
•
Guenther, E.
•
Hatzes, A. P.
•
Kusakabe, N.
•
Latham, D. W.
•
Libralato, M.
•
Luque, R.
•
Montañés-Rodríguez, P.
•
Murgas, F.
•
Nardiello, D.
•
•
Piotto, G.
•
Persson, C. M.
•
Redfield, S.
•
Tamura, M.
DOI
Abstract
We present a detailed analysis of HARPS-N radial velocity observations of K2-100, a young and active star in the Praesepe cluster, which hosts a transiting planet with a period of 1.7 d. We model the activity-induced radial velocity variations of the host star with a multidimensional Gaussian Process framework and detect a planetary signal of 10.6 ± 3.0 {m s^{-1}}, which matches the transit ephemeris, and translates to a planet mass of 21.8 ± 6.2 M⊕. We perform a suite of validation tests to confirm that our detected signal is genuine. This is the first mass measurement for a transiting planet in a young open cluster. The relatively low density of the planet, 2.04 _{ - 0.61 } ^ { + 0.66 } {g cm^{-3}}, implies that K2-100b retains a significant volatile envelope. We estimate that the planet is losing its atmosphere at a rate of 10^{11}-10^{12} {g s^{-1}} due to the high level of radiation it receives from its host star.
Volume
490
Issue
1
Start page
698
Uri
Url
Issn Identifier
0035-8711
Ads BibCode
2019MNRAS.490..698B
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

1909.05252.pdf

Description
preprint
Size

1014.14 KB

Format

Adobe PDF

Checksum (MD5)

c152198aea628bca1129431cec16efc4

Loading...
Thumbnail Image
Name

stz2569.pdf

Description
Pdf editoriale
Size

1.95 MB

Format

Unknown

Checksum (MD5)

ac5cd525881979660fd50817a541563f