Please use this identifier to cite or link to this item:
Title: Three planets transiting the evolved star EPIC 249893012: A hot 8.8-M super-Earth and two warm 14.7 and 10.2-M sub-Neptunes
Authors: Hidalgo, D.
Pallé, E.
Alonso, R.
Gandolfi, D.
Fridlund, M.
Nowak, G.
Luque, R.
Hirano, T.
Justesen, A. B.
Cochran, W. D.
Barragán, O.
Spina, L.
Rodler, F.
Albrecht, S.
Anderson, D.
Amado, P. J.
Bryant, E.
Caballero, J. A.
Cabrera, J.
Csizmadia, Sz.
Dai, F.
De Leon, J.
Deeg, H. J.
Eigmuller, Ph.
Endl, M.
Erikson, A.
Esposito, M.
Figueira, P.
Georgieva, I.
Grziwa, S.
Guenther, E. W.
Hatzes, A. P.
Hjorth, M.
Hoeijmakers, H. J.
Kabath, P.
Korth, J.
Kuzuhara, M.
Lafarga, M.
Lampón, M.
Leao, I. C.
Livingston, J.
Mathur, S.
Montañés Rodríguez, P.
Morales, J. C.
Murgas Alcaino, F.
Nagel, E.
Narita, N.
Nielsen, L. D.
Patzold, M.
Persson, C. M.
Prieto Arranz, J.
Quirrenbach, A.
Rauer, H.
Redfield, S.
Reiners, A.
Ribas, I.
Smith, A. M. S.
Subjak, J.
Van Eylen, V.
Wilson, P. A.
Keywords: Planetary systems;Planets and satellites: detection;Planets and satellites: fundamental parameters;Techniques: photometric;Techniques: radial velocities
Issue Date: 24-Apr-2020
Publisher: EDP Sciences
DOI: 10.1051/0004-6361/201937080
Published version:
Citation: Astronomy & Astrophysics 636: A89 (2020)
Abstract: We report the discovery of a new planetary system with three transiting planets, one super-Earth and two sub-Neptunes, that orbit EPIC 249893012, a G8 IV-V evolved star ( M ? = 1.05 0.05 M fi, R ? = 1.71 0.04 R fi, Te ff = 5430 85 K). The star is just leaving the main sequence. We combined K2 photometry with IRCS adaptive-optics imaging and HARPS, HARPS-N, and CARMENES highprecision radial velocity measurements to confirm the planetary system, determine the stellar parameters, and measure radii, masses, and densities of the three planets. With an orbital period of 3:5949+0:0007 0:0007 days, a mass of 8:75+1:09 1:08 M , and a radius of 1:95+0:09 0:08 R , the inner planet b is compatible with nickel-iron core and a silicate mantle ( b = 6:39+1:19 1:04 g cm 3). Planets c and d with orbital periods of 15:624+0:001 0:001 and 35:747+0:005 0:005 days, respectively, have masses and radii of 14:67+1;84 1:89 M and 3:67+0:17 0:14 R and 10:18+2:46 2:42 M and 3:94+0:13 0:12 R , respectively, yielding a mean density of 1:62+0:30 0:29 and 0:91+0:25 0:23 g cm 3, respectively. The radius of planet b lies in the transition region between rocky and gaseous planets, but its density is consistent with a rocky composition. Its semimajor axis and the corresponding photoevaporation levels to which the planet has been exposed might explain its measured density today. In contrast, the densities and semimajor axes of planets c and d suggest a very thick atmosphere. The singularity of this system, which orbits a slightly evolved star that is just leaving the main sequence, makes it a good candidate for a deeper study from a dynamical point of view.
E-ISSN: 1432-0746
ISSN: 0004-6361
Appears in Collections:(CAB) Artículos

Files in This Item:
File Description SizeFormat 
aa37080-19.pdf1,07 MBAdobe PDFThumbnail

This item is licensed under a Creative Commons License Creative Commons