Gliese 86 b

{{Short description|Jovian planet orbiting Gliese 86 A}}

{{Infobox planet

| name = Gliese 86 b

| image = Gliese 86 Ab (Celestia).jpg

| caption = The exoplanet Gliese 86 Ab (min mass ~4 MJ) rendered by Celestia

| discoverer = Mayor et al.Michel Mayor, Didier Queloz, Udry et al.

| discovery_site = {{flag|France}}

| discovered = 24 November 1998

| discovery_method = Doppler spectroscopy

| apsis = astron

| semimajor = {{val|0.1177|0.0015|0.0012|ul=AU}}

| eccentricity = {{val|0.0478|0.0024}}

| period = 15.76491 ± 0.00039 d

| time_periastron = 2451903.36 ± 0.59

| arg_peri = 269 ± 16

| semi-amplitude = 376.7 ± 2.9

| star = Gliese 86

| mass = ≥{{val|4.266|0.11|0.087|ul=Jupiter mass}}

}}

Gliese 86 b, sometimes referred to as Gliese 86 A b{{cite journal | arxiv=2112.06394| last1=Zeng| first1=Yunlin| last2=Brandt| first2=Timothy D.| last3=Li| first3=Gongjie| last4=Dupuy| first4=Trent J.| last5=Li| first5=Yiting| last6=Mirek Brandt| first6=G.| last7=Farihi| first7=Jay| last8=Horner| first8=Jonathan| last9=Wittenmyer| first9=Robert A.| last10=Butler| first10=R. Paul.| last11=Tinney| first11=Christopher G.| last12=Carter| first12=Bradley D.| last13=Wright| first13=Duncan J.| last14=Jones| first14=Hugh R. A.| last15=O'Toole| first15=Simon J.| title=The Gliese 86 Binary System: A Warm Jupiter Formed in a Disk Truncated at ≈2 au| journal=The Astronomical Journal| year=2022| volume=164| issue=5| page=188| doi=10.3847/1538-3881/ac8ff7| bibcode=2022AJ....164..188Z| s2cid=245123923| doi-access=free}} (so as to distinguish the planet from companion star "B") and/or shortened to Gl 86 b, is an extrasolar planet approximately 35 light-years away in the constellation of Eridanus. The planet was discovered orbiting a K-type main-sequence star (Gliese 86 A) by French scientists in November 1998. The planet orbits very close to the star, completing an orbit in 15.78 days.

Preliminary astrometric measurements made with the Hipparcos space probe suggested the planet has an orbital inclination of 164.0° and a mass 15 times that of Jupiter, which would make the object a brown dwarf.{{cite journal | author=Han | title=Preliminary astrometric masses for proposed extrasolar planetary companions | journal=The Astrophysical Journal Letters | volume=548 | issue=1 | pages=L57–L60 | date=2001 | doi=10.1086/318927 | last2=Black | first2=David C. | last3=Gatewood | first3=George | bibcode=2001ApJ...548L..57H | doi-access=free }} However, further analysis suggests the Hipparcos measurements are not precise enough to reliably determine astrometric orbits of substellar companions, thus the orbital inclination and true mass of the candidate planet remain unknown.{{cite journal|bibcode=2001A&A...372..935P|title=Screening the Hipparcos-based astrometric orbits of sub-stellar objects|author1=Pourbaix, D. |author2=Arenou, F.|journal=Astronomy and Astrophysics|volume=372|issue=3|pages=935–944|date=2001|doi=10.1051/0004-6361:20010597|arxiv = astro-ph/0104412 |s2cid=378792 }}