 Artist's impression of a Neptune-type exoplanet like Gliese 15 Ac. | |
| Discovery[1] | |
|---|---|
| Discovered by | Pinamonti et al. |
| Discovery site | HARPS-N |
| Discovery date | April 2018 |
| Radial velocity | |
| Designations | |
| Groombridge 34 Ac, GX Andromedae c | |
| Orbital characteristics | |
| 5.4+1.0 −0.9 AU[1] | |
| Eccentricity | 0.27+0.28 −0.19[1] |
| 7600+2200 −1700 d[1] | |
| −58.40+100.80 −53.30[1][2] | |
| Semi-amplitude | 2.5+1.3 −1.0[1] |
| Star | Groombridge 34 A |
| Physical characteristics | |
| Mass | ≥36+25 −18 ME[1] |
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]
