TY - JOUR
T1 - DISCOVERY and VALIDATION of A HIGH-DENSITY SUB-NEPTUNE from the K2 MISSION
AU - Espinoza, Néstor
AU - Brahm, Rafael
AU - Jordán, Andrés
AU - Jenkins, James S.
AU - Rojas, Felipe
AU - Jofré, Paula
AU - Mädler, Thomas
AU - Rabus, Markus
AU - Chanamé, Julio
AU - Pantoja, Blake
AU - Soto, Maritza G.
AU - Morzinski, Katie M.
AU - Males, Jared R.
AU - Ward-Duong, Kimberly
AU - Close, Laird M.
N1 - Funding Information:
NE and RB are supported by CONICYT-PCHA/Doctorado Nacional. AJ acknowledges support from FONDECYT project 1130857 and from BASAL CATA PFB-06. NE, RB AJ and JC acknowledge support from the Ministry for the Economy, Development, and Tourism Programa Iniciativa Cientifica Milenio through grant IC 120009, awarded to the Millennium Institute of Astrophysics (MAS). JSJ acknowledges support from BASAL CATA PFB- 06. This paper includes data collected by the Kepler mission. Funding for the Kepler mission is provided by the NASA Science Mission directorate. It also made use of the SIMBAD database (operated at CDS, Strasbourg, France), NASAs Astrophysics Data System Bibliographic Services, and data products from the Two Micron All Sky Survey (2MASS) and the APASS database and the Digitized Sky Survey. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 096.C-0499(A), 096.C-0417(A) and 096.D- 0402(A).
Publisher Copyright:
© 2016. The American Astronomical Society. All rights reserved.
PY - 2016/10/10
Y1 - 2016/10/10
N2 - We report the discovery of K2-56b, a high-density sub-Neptune exoplanet, made using photometry from Campaign 4 of the two-wheeled Kepler (K2) mission, ground-based radial velocity (RV) follow-up from HARPS and high-resolution lucky and adaptive optics imaging obtained using AstraLux and MagAO, respectively. The host star is a bright (V = 11.04, K s = 9.37), slightly metal-poor ([Fe/H] = -0.15 0.05 dex) solar analogue located at pc from Earth, for which we find a radius of and a mass of . A joint analysis of the K2 photometry and HARPS RVs reveal that the planet is in a ≈42 day orbit around its host star, has a radius of , and a mass of . Although the data at hand put the planet in the region of the mass-radius diagram where we could expect planets with a pure rock (i.e., magnesium silicate) composition using two-layer models (i.e., between rock/iron and rock/ice compositions), we discuss more realistic three-layer composition models which can explain the high density of the discovered exoplanet. The fact that the planet lies in the boundary between "possibly rocky" and "non-rocky" exoplanets makes it an interesting planet for future RV follow-up.
AB - We report the discovery of K2-56b, a high-density sub-Neptune exoplanet, made using photometry from Campaign 4 of the two-wheeled Kepler (K2) mission, ground-based radial velocity (RV) follow-up from HARPS and high-resolution lucky and adaptive optics imaging obtained using AstraLux and MagAO, respectively. The host star is a bright (V = 11.04, K s = 9.37), slightly metal-poor ([Fe/H] = -0.15 0.05 dex) solar analogue located at pc from Earth, for which we find a radius of and a mass of . A joint analysis of the K2 photometry and HARPS RVs reveal that the planet is in a ≈42 day orbit around its host star, has a radius of , and a mass of . Although the data at hand put the planet in the region of the mass-radius diagram where we could expect planets with a pure rock (i.e., magnesium silicate) composition using two-layer models (i.e., between rock/iron and rock/ice compositions), we discuss more realistic three-layer composition models which can explain the high density of the discovered exoplanet. The fact that the planet lies in the boundary between "possibly rocky" and "non-rocky" exoplanets makes it an interesting planet for future RV follow-up.
KW - composition
KW - detection
KW - fundamental parameters
KW - planets and satellites
KW - planets and satellites
KW - planets and satellites
KW - planets and satellites
KW - terrestrial planets
UR - https://www.scopus.com/pages/publications/84991107480
UR - https://www.scopus.com/pages/publications/84991107480#tab=citedBy
U2 - 10.3847/0004-637X/830/1/43
DO - 10.3847/0004-637X/830/1/43
M3 - Article
AN - SCOPUS:84991107480
SN - 0004-637X
VL - 830
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 43
ER -