Gliese 15 Ac

Gliese 15 Ac
	Artist's impression of a Neptune-type exoplanet like Gliese 15 Ac.
Discovery
Discovered by	Pinamonti et al.
Discovery site	HARPS-N
Discovery date	April 2018
Detection method	Radial velocity
Designations
Alternative names	Groombridge 34 Ac, GX Andromedae c
Orbital characteristics
Semi-major axis	5.4+1.0; −0.9 AU
Eccentricity	0.27+0.28; −0.19
Orbital period (sidereal)	7600+2200; −1700 d
Longitude of periastron	−58.40+100.80; −53.30
Semi-amplitude	2.5+1.3; −1.0
Star	Groombridge 34 A
Physical characteristics
Mass	≥36+25; −18 ME

Gliese 15 Ac (also known as Groombridge 34 Ac, GX Andromedae c) is an exoplanet orbiting the nearby red dwarf star Gliese 15 A (Groombridge 34 A, GX Andromedae), which is part of a binary star system located about 11.6 light-years^[3] from the Sun. The planet was first proposed in October 2017 using radial velocity data from the CARMENES spectrograph, combined with measurements from the HARPS and HIRES spectrographs,^[4] and its existence was confirmed in April 2018 using HARPS-N data.^[1] It has a minimum mass 36 times that of Earth and orbits at around 5.4 astronomical units with a period of 7,600 days (21 years), an orbit which may have been sculpted by interaction with the companion star, Gliese 15 B.^[1]^[5] As of 2020, Gliese 15 Ac is the longest-period sub-Jovian planet discovered by radial velocity.^[1]^[2]

References

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Pinamonti, M.; Damasso, M.; Marzari, F.; Sozzetti, A.; Desidera, S.; Maldonado, J.; Scandariato, G.; Affer, L.; Lanza, A. F.; Bignamini, A.; Bonomo, A. S.; Borsa, F.; Claudi, R.; Cosentino, R.; Giacobbe, P.; González-Álvarez, E.; González Hernández, J. I.; Gratton, R.; Leto, G.; Malavolta, L.; Martinez Fiorenzano, A.; Micela, G.; Molinari, E.; Pagano, I.; Pedani, M.; Perger, M.; Piotto, G.; Rebolo, R.; Ribas, I.; et al. (2018). "The HADES RV Programme with HARPS-N at TNG. VIII. GJ15A: A multiple wide planetary system sculpted by binary interaction". Astronomy and Astrophysics. 617: A104. arXiv:1804.03476. Bibcode:2018A&A...617A.104P. doi:10.1051/0004-6361/201732535.
^ ^a ^b "GJ 15 A c". NASA Exoplanet Archive. Archived from the original on 5 October 2023. Retrieved 1 August 2020.
^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
^ Trifonov, Trifon; Kürster, Martin; Zechmeister, Mathias; Tal-Or, Lev; Caballero, José A.; Quirrenbach, Andreas; Amado, Pedro J.; Ribas, Ignasi; Reiners, Ansgar; et al. (2018). "The CARMENES search for exoplanets around M dwarfs. First visual-channel radial-velocity measurements and orbital parameter updates of seven M-dwarf planetary systems". Astronomy and Astrophysics. 609. A117. arXiv:1710.01595. Bibcode:2018A&A...609A.117T. doi:10.1051/0004-6361/201731442. S2CID 119340839.
^ Brennan, Pat. "Discovery Alert: 2-planet System Is Close – and Weird". NASA. Archived from the original on 28 July 2020. Retrieved 1 August 2020.