학술논문
The CARMENES search for exoplanets around M dwarfs Detection of a mini-Neptune around LSPM J2116+0234 and refinement of orbital parameters of a super-Earth around GJ 686 (BD+18 3421)
Document Type
Working Paper
Author
Lalitha, S.; Baroch, D.; Morales, J. C.; Passegger, V. M.; Bauer, F. F.; Guillén, C. Cardona; Dreizler, S.; Oshagh, M.; Reiners, A.; Ribas, I.; Caballero, J. A.; Quirrenbach, A.; Amado, P. J.; Béjar, V. J. S.; Colomé, J.; Cortés-Contreras, M.; Galadí-Enríquez, D.; González-Cuesta, L.; Guenther, E. W.; Hagen, H. -J.; Henning, T.; Herrero, E.; Husser, T. -O.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; Lodieu, N.; López-González, M. J.; Montes, D.; Perger, M.; Rosich, A.; Rodríguez, E.; Rodríguez-López, C.; Schmitt, J. H. M. M.; Tal-Or, L.; Zechmeister, M.
Source
A&A 627, A116 (2019)
Subject
Language
Abstract
Although M dwarfs are known for high levels of stellar activity, they are ideal targets for the search of low-mass exoplanets with the radial velocity (RV) method. We report the discovery of a planetary-mass companion around LSPM J2116+0234 (M3.0 V) and confirm the existence of a planet orbiting GJ 686 (BD+18 3421; M1.0 V). The discovery of the planet around LSPM J2116+0234 is based on CARMENES RV observations in the visual and near-infrared channels. We confirm the planet orbiting around GJ 686 by analyzing the RV data spanning over two decades of observations from CARMENES VIS, HARPS-N, HARPS, and HIRES. We find planetary signals at 14.44 and 15.53 d in the RV data for LSPM J2116+0234 and GJ 686, respectively. Additionally, the RV, photometric time series, and various spectroscopic indicators show hints of variations of 42 d for LSPM J2116+0234 and 37 d for GJ 686, which we attribute to the stellar rotation periods. The orbital parameters of the planets are modeled with Keplerian fits together with correlated noise from the stellar activity. A mini-Neptune with a minimum mass of 11.8 Me orbits LSPM J2116+0234 producing an RV semi-amplitude of 6.19 m/s, while a super-Earth of mass 6.6 Me orbits GJ 686 and produces an RV semi-amplitude of 3.0 m/s. Both LSPM J2116+0234 and GJ 686 have planetary companions populating the regime of exoplanets with masses lower than 15 Me and orbital periods <20 d.
Comment: 23 pages, 22 figures, accepted for publication in A&A
Comment: 23 pages, 22 figures, accepted for publication in A&A