Gliese 15 Ab


Gliese 15 Ab
Discovered byAndrew W. Howard
Discovery siteKeck Observatory
Discovery dateAugust, 2014
Radial velocity
Orbital characteristics
0.074±0.001 AU
StarGroombridge 34A

Gliese 15 Ab (GJ 15Ab), also commonly called Groombridge 34 Ab,[note 1] is an extrasolar planet approximately 11 light-years away in the constellation of Andromeda. It is found in the night sky orbiting the star Gliese 15 A, which is at right ascension 00h 18m 22.89s and declination +44° 01′ 22.6″.[1]

It was discovered in August 2014,[2] deduced from analysis of the radial velocities of the parent Star by the Eta-Earth Survey using HIRES at Keck Observatory. It has around 5.35 ± 0.75 Earth masses,[2] and is thought to be a Super-Earth with a diameter greater than that of the Earth. However, researches using the CARMENES spectrograph failed to detect the planet.[3]

Gliese 15 Ab has a close inner orbit around Gliese 15 A with a semi-major axis of only 0.0717 ± 0.0034 AU, making an orbital period that is just a little longer than 11.4 days, the orbit appears to be relatively circular, with an orbital eccentricity of about 0.12. It orbits too close to Gliese 15 A to be located in the habitable zone and is unlikely to harbour life.


  1. ^ In the discovery paper, discoverers call this object "Gl 15 Ab", and never "Groombridge 34 Ab".


  1. ^ F. van Leeuwen (2007) Validation of the new Hipparcos reduction. Astronomy and Astrophysics 474 (2): 653–664.
  2. ^ a b Andrew Howard, Geoffrey Marcy, Debra A. Fischer, Howard Isaacson, Philip S. Muirhead, Gregory W. Henry, Tabetha S. Boyajian, Kaspar von Braun, Juliette C. Becker, Jason T. Wright, John Asher Johnson, Astrophysics Earth and Planetary Astrophysics : The NASA-UC-UH Eta-Earth Program: IV. A Low-mass Planet Orbiting an M Dwarf 3.6 PC from Earth.
  3. ^ 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.

External links

  • Open Exoplanet Catalogue entry