2020A&A...636A..89H


C.D.S. - SIMBAD4 rel 1.7 - 2020.11.25CET10:31:59

2020A&A...636A..89H - Astronomy and Astrophysics, volume 636A, 89-89 (2020/4-1)

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.

HIDALGO D., PALLE E., ALONSO R., GANDOLFI D., FRIDLUND M., NOWAK G., LUQUE R., HIRANO T., JUSTESEN A.B., COCHRAN W.D., BARRAGAN O., SPINA L., RODLER F., ALBRECHT S., ANDERSON D., AMADO P., BRYANT E., CABALLERO J.A., CABRERA J., CSIZMADIA S., DAI F., DE LEON J., DEEG H.J., EIGMULLER P., ENDL M., ERIKSON A., ESPOSITO M., FIGUEIRA P., GEORGIEVA I., GRZIWA S., GUENTHER E., HATZES A.P., HJORTH M., HOEIJMAKERS H.J., KABATH P., KORTH J., KUZUHARA M., LAFARGA M., LAMPON M., LEAO I.C., LIVINGSTON J., MATHUR S., MONTANES-RODRIGUEZ P., MORALES J.C., MURGAS 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. and WILSON P.A.

Abstract (from CDS):

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±0.05M, R*=1.71±0.04R, Teff=5430±85K). The star is just leaving the main sequence. We combined K2 photometry with IRCS adaptive-optics imaging and HARPS, HARPS-N, and CARMENES high-precision 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 8.75–1.08+1.09M, and a radius of 1.95–0.08+0.09R, the inner planet b is compatible with nickel-iron core and a silicate mantle (ρb=6.39–1.04+1.19g/cm3). 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 14.67–1.89+1.84M and 3.67–0.14+0.17R and 10.18–2.42+2.46M and 3.94–0.12+0.13R, respectively, yielding a mean density of 1.62–0.29+0.30 and 0.91–0.23+0.25g/cm3, 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.

Abstract Copyright: © ESO 2020

Journal keyword(s): planetary systems - planets and satellites: detection - techniques: photometric - techniques: radial velocities - planets and satellites: fundamental parameters

Simbad objects: 5

goto Full paper

goto View the reference in ADS

Number of rows : 5

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 K2-314 * 15 12 59.5618444224 -16 43 28.199087676   12.355 11.577     ~ 2 0
2 K2-314c Pl 15 12 59.5618444224 -16 43 28.199087676           ~ 3 0
3 K2-314d Pl 15 12 59.5618444224 -16 43 28.199087676           ~ 2 0
4 K2-314b Pl 15 12 59.5618444224 -16 43 28.199087676           ~ 1 0
5 Gaia DR2 6259260177825579136 * 15 13 00.0556498729 -16 43 33.459228757           ~ 1 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2020A&A...636A..89H and select 'bookmark this link' or equivalent in the popup menu


2020.11.25-10:31:59

© Université de Strasbourg/CNRS

    • Contact