The CARMENES search for exoplanets around M dwarfs HD147379 b: A nearby Neptune in the temperate zone of an early-M dwarf Reiners, A. Rabaza Castillo, Ovidio Suárez Yanes, Juan Carlos Stars: individual: HD147379 Planets and satellites: individual: HD147379 b Stars: activity Stars: rotation Stars: late-type Stars: low-mass We report on the first star discovered to host a planet detected by radial velocity (RV) observations obtained within the CARMENES survey for exoplanets around M dwarfs. HD 147379 (V = 8.9 mag, M = 0.58 ± 0.08 M⊙), a bright M0.0 V star at a distance of 10.7 pc, is found to undergo periodic RV variations with a semi-amplitude of K = 5.1 ± 0.4 m s−1 and a period of P = 86.54 ± 0.06 d. The RV signal is found in our CARMENES data, which were taken between 2016 and 2017, and is supported by HIRES/Keck observations that were obtained since 2000. The RV variations are interpreted as resulting from a planet of minimum mass mP sin i = 25 ± 2 M⊕, 1.5 times the mass of Neptune, with an orbital semi-major axis a = 0.32 au and low eccentricity (e < 0.13). HD 147379 b is orbiting inside the temperate zone around the star, where water could exist in liquid form. The RV time-series and various spectroscopic indicators show additional hints of variations at an approximate period of 21.1 d (and its first harmonic), which we attribute to the rotation period of the star. 2018-09-19T11:28:05Z 2018-09-19T11:28:05Z 2018 info:eu-repo/semantics/article Reiners, A. et. al. The CARMENES search for exoplanets around M dwarfs HD147379 b: A nearby Neptune in the temperate zone of an early-M dwarf. A&A 609, L5 (2018) [http://hdl.handle.net/10481/52765] http://hdl.handle.net/10481/52765 10.1051/0004-6361/201732165 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ info:eu-repo/semantics/openAccess Atribución-NoComercial-SinDerivadas 3.0 España EDP Sciences