Detection and characterization of an ultra-dense sub-Neptunian planet orbiting the Sun-like star K2-292

DOI: 
10.1051/0004-6361/201834952
Publication date: 
01/03/2019
Main author: 
Luque, R.
IAA authors: 
Bauer, F.;Amado, P. J.
Authors: 
Luque, R.;Nowak, G.;Pallé, E.;Dai, F.;Kaminski, A.;Nagel, E.;Hidalgo, D.;Bauer, F.;Lafarga, M.;Livingston, J.;Barragán, O.;Hirano, T.;Fridlund, M.;Gandolfi, D.;Justesen, A. B.;Hjorth, M.;Van Eylen, V.;Winn, J. N.;Esposito, M.;Morales, J. C.;Albrecht, S.;Alonso, R.;Amado, P. J.;Beck, P.;Caballero, J. A.;Cabrera, J.;Cochran, W. D.;Csizmadia, Sz.;Deeg, H.;Eigmüller, Ph.;Endl, M.;Erikson, A.;Fukui, A.;Grziwa, S.;Guenther, E. W.;Hatzes, A. P.;Knudstrup, E.;Korth, J.;Lam, K. W. F.;Lund, M. N.;Mathur, S.;Montañes-Rodríguez, P.;Narita, N.;Nespral, D.;Niraula, P.;Pätzold, M.;Persson, C. M.;Prieto-Arranz, J.;Quirrenbach, A.;Rauer, H.;Redfield, S.;Reiners, A.;Ribas, I.;Smith, A. M. S.
Journal: 
Astronomy and Astrophysics
Refereed: 
Yes
Publication type: 
Article
Volume: 
623
Pages: 
A114
Abstract: 
We present the discovery and characterization of a new transiting planet from Campaign 17 of the Kepler extended mission K2. The planet K2-292 b is a warm sub-Neptune on a 17 day orbit around a bright (V = 9.9 mag) solar-like G3 V star with a mass and radius of M<SUB>⋆</SUB> = 1.00 ± 0.03 M<SUB>☉</SUB> and R<SUB>⋆</SUB> = 1.09 ± 0.03 R<SUB>☉</SUB>, respectively. We modeled simultaneously the K2 photometry and CARMENES spectroscopic data and derived a radius of R<SUB>p</SUB>=2.63<SUB>-0.10</SUB><SUP>+0.12</SUP> R<SUB>⊕</SUB> and mass of M<SUB>p</SUB>=24.5<SUB>-4.4</SUB><SUP>+4.4</SUP> M<SUB>⊕</SUB>, yielding a mean density of ρ<SUB>p</SUB>=7.4<SUB>-1.5</SUB><SUP>+1.6</SUP> g cm<SUP>-3</SUP>, which makes it one of the densest sub-Neptunian planets known to date. We also detected a linear trend in the radial velocities of K2-292 (γ̇<SUB>RV</SUB> = -0.40<SUB>-0.07</SUB><SUP>+0.07</SUP> m s<SUP>-1</SUP> d<SUP>-1</SUP>) that suggests a long-period companion with a minimum mass on the order of 33 M<SUB>⊕</SUB>. If confirmed, it would support a formation scenario of K2-292 b by migration caused by Kozai-Lidov oscillations. The light curve is only available at the CDS via anonymous ftp to <A href='http://cdsarc.u-strasbg.fr'>http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href='http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A114'>http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A114</A>
Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063048019&doi=10.1051%2f0004-6361%2f201834952&partnerID=40&md5=eea07250f4f067f5cc633d5d3e683340
ADS Bibcode: 
2019A&A...623A.114L
Keywords: 
planetary systems;techniques: photometric;techniques: radial velocities;techniques: high angular resolution;stars: individual: HD 119130;stars: individual: K2-292;Astrophysics - Earth and Planetary Astrophysics