Gliese 15 Ac

{{Infobox planet

| extrasolarplanet = yes

| name = Gliese 15 Ac

| image = Exo-Neptune art.jpg

| image_size =

| image_alt =

| caption = Artist's impression of a Neptune-type exoplanet like Gliese 15 Ac.

| apsis = astron

| discovery_ref =

| discoverer = Pinamonti et al.

| discovery_site = HARPS-N

| discovered = April 2018

| discovery_method = Radial velocity

| alt_names = Groombridge 34 Ac, GX Andromedae c

| periastron =

| apoastron =

| semimajor = {{val|5.4|1.0|0.9}} AU

| avg_speed =

| eccentricity = {{val|0.27|0.28|0.19}}

| period = {{val|7600|2200|1700}} d

| inclination =

| angular_dist =

| asc_node =

| long_periastron = {{val|-58.40|100.80|53.30}}

| time_periastron =

| semi-amplitude = {{val|2.5|1.3|1.0}}

| star = Groombridge 34 A

| mean_radius =

| surface_area =

| volume =

| density =

| mass = ≥{{val|36|25|18}} {{Earth mass|link=y}}

| surface_grav =

| moment_of_inertia_factor =

| escape_velocity =

| albedo =

| single_temperature =

}}

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{{cite DR2|385334230892516480}} 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, and its existence was confirmed in April 2018 using HARPS-N data. It has a minimum mass 36 times that of Earth and orbits at around 5.4 astronomical units with a period of {{convert|7600|days|years|abbr=off}}, an orbit which may have been sculpted by interaction with the companion star, Gliese 15 B. As of 2020, Gliese 15 Ac is the longest-period sub-Jovian planet discovered by radial velocity.

References

{{reflist|refs=

{{cite journal |doi=10.1051/0004-6361/201731442 |title=The CARMENES search for exoplanets around M dwarfs. First visual-channel radial-velocity measurements and orbital parameter updates of seven M-dwarf planetary systems |last1=Trifonov |first1=Trifon |last2=Kürster |first2=Martin |last3=Zechmeister |first3=Mathias |last4=Tal-Or |first4=Lev |last5=Caballero |first5=José A. |last6=Quirrenbach |first6=Andreas |last7=Amado |first7=Pedro J. |last8=Ribas |first8=Ignasi |last9=Reiners |first9=Ansgar |last10=Reffert |first10=Sabine |last11=Dreizler |first11=Stefan |last12=Hatzes |first12=Artie P. |last13=Kaminski |first13=Adrian |last14=Launhardt |first14=Ralf |last15=Henning |first15=Thomas K. |last16=Montes |first16=David |last17=Béjar |first17=Victor J. S. |last18=Mundt |first18=Reinhard |last19=Pavlov |first19=Aleksei |last20=Schmitt |first20=Jürgen H. M. M. |last21=Seifert |first21=Walter |last22=Morales |first22=Juan Carlos |last23=Nowak |first23=Grzegorz |last24=Jeffers |first24=Sandra V. |last25=Rodríguez-López |first25=Cristina |last26=del Burgo |first26=Carlos |last27=Anglada-Escudé |first27=Guillem |last28=López-Santiago |first28=Javier |last29=Mathar |first29=Richard J. |last30=Ammler-von Eiff |first30=Matthias |display-authors=9 |journal=Astronomy and Astrophysics |volume=609 |at=A117 |year=2018 |arxiv=1710.01595 |bibcode=2018A&A...609A.117T |s2cid=119340839 }}

{{cite journal|bibcode=2018A&A...617A.104P|title=The HADES RV Programme with HARPS-N at TNG. VIII. GJ15A: A multiple wide planetary system sculpted by binary interaction|journal=Astronomy and Astrophysics|volume=617|pages=A104|last1=Pinamonti|first1=M.|last2=Damasso|first2=M.|last3=Marzari|first3=F.|last4=Sozzetti|first4=A.|last5=Desidera|first5=S.|last6=Maldonado|first6=J.|last7=Scandariato|first7=G.|last8=Affer|first8=L.|last9=Lanza|first9=A. F.|last10=Bignamini|first10=A.|last11=Bonomo|first11=A. S.|last12=Borsa|first12=F.|last13=Claudi|first13=R.|last14=Cosentino|first14=R.|last15=Giacobbe|first15=P.|last16=González-Álvarez|first16=E.|last17=González Hernández|first17=J. I.|last18=Gratton|first18=R.|last19=Leto|first19=G.|last20=Malavolta|first20=L.|last21=Martinez Fiorenzano|first21=A.|last22=Micela|first22=G.|last23=Molinari|first23=E.|last24=Pagano|first24=I.|last25=Pedani|first25=M.|last26=Perger|first26=M.|last27=Piotto|first27=G.|last28=Rebolo|first28=R.|last29=Ribas|first29=I.|last30=Suárez Mascareño|first30=A.|display-authors=29|year=2018|arxiv=1804.03476|doi=10.1051/0004-6361/201732535}}

{{cite web |last1=Brennan |first1=Pat |title=Discovery Alert: 2-planet System Is Close – and Weird |url=https://exoplanets.nasa.gov/news/1606/discovery-alert-2-planet-system-is-close-and-weird/ |website=NASA |accessdate=1 August 2020 |archive-date=28 July 2020 |archive-url=https://web.archive.org/web/20200728105332/https://exoplanets.nasa.gov/news/1606/discovery-alert-2-planet-system-is-close-and-weird/ |url-status=live }}

{{cite web |title=GJ 15 A c |url=https://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?objname=GJ+15+A+c&type=CONFIRMED_PLANET |website=NASA Exoplanet Archive |accessdate=1 August 2020 |archive-date=5 October 2023 |archive-url=https://web.archive.org/web/20231005141120/https://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?objname=GJ+15+A+c&type=CONFIRMED_PLANET |url-status=live }}

}}

Category:Exoplanets discovered in 2018

Category:Exoplanets detected by radial velocity

Category:Exoplanets in the Gliese Catalog

fr:Gliese_15#Les_planètes_GJ_15_Ab_et_GJ_15_Ac