HD 108863#Planetary system

{{Short description|Star in the constellation Coma Berenices}}

{{Starbox begin

| name = HD 108863

}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|12|30|19.9101}}

| dec = {{DEC|+21|56|53.6794}}

| constell = Coma Berenices

| appmag_v = 7.71{{citation|arxiv=1811.03043|title=Retired A Stars and Their Companions VIII: 15 New Planetary Signals Around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts|year=2018|doi=10.3847/1538-3881/aaf5d0|last1=Luhn|first1=Jacob K.|last2=Bastien|first2=Fabienne A.|last3=Wright|first3=Jason T.|last4=Johnson|first4=John A.|last5=Howard|first5=Andrew W.|last6=Isaacson|first6=Howard|journal=The Astronomical Journal |volume=157 |issue=4 |page=149 |bibcode=2019AJ....157..149L |s2cid=102486961 |doi-access=free }}

}}

{{Starbox character

| type = subgiant

| class = K0III-IV

| b-v = 0.99

| variable =

}}

{{Starbox astrometry

| radial_v = −27.832

| prop_mo_ra = −75.501

| prop_mo_dec = −33.669

| parallax = 6.0417

| p_error = 0.0485

| parallax_footnote =

}}

{{Starbox orbit

| reference =

| primary = HD 108863

| name = HD 108863 B

| period =

| period_unitless =

| axis = 0.115

| axis_unitless = 16.065 AU

| eccentricity =

| inclination =

| node =

| periastron =

| periarg =

| periarg_primary =

| k1 =

| k2 =

}}

{{Starbox detail

| source =

| mass = 1.59

| radius = 5.74

| gravity = 3.07

| luminosity =

| temperature = 4,878

| metal = 0.02{{citation|arxiv=1804.09082|year=2018|doi=10.3847/1538-4357/aac37c|last1=Ghezzi|first1=Luan|last2=Montet|first2=Benjamin T.|last3=Johnson|first3=John Asher|title=Retired a Stars Revisited: An Updated Giant Planet Occurrence Rate as a Function of Stellar Metallicity and Mass|journal=The Astrophysical Journal|volume=860|issue=2|page=109|bibcode=2018ApJ...860..109G|s2cid=118969017 |doi-access=free }}

| rotation =

| rotational_velocity = {{val|1.6|0.6}}

| age_gyr = {{val|1.8|0.4}}{{citation|arxiv=1311.2947|title=Herschel Observations of Debris Discs Orbiting Planet-hosting Subgiants|year=2013|doi=10.1093/mnras/stt2128|last1=Bonsor|first1=Amy|last2=Kennedy|first2=Grant M.|last3=Wyatt|first3=Mark C.|last4=Johnson|first4=John A.|last5=Sibthorpe|first5=Bruce|journal=Monthly Notices of the Royal Astronomical Society|volume=437|issue=4|pages=3288–3297|doi-access=free |s2cid=53586078}}

}}

{{Starbox catalog

| names = {{odlist|HD=108863|BD=+22 2478|2MASS=J12301991+2156537|Gaia DR2=3952692457305436800|HIP=61020|TYC=1447-2345-1}}

}}

{{Starbox reference

| Simbad = HD+108863

}}

{{Starbox end}}

HD 108863 is a subgiant star, the primary of a binary star system {{val|540|u=light-years}} away, belonging to spectral class K0. Its age is younger than the Sun's at {{val|1.8|0.4}} billion years. The primary star is slightly enriched in heavy elements, having 115% of solar abundance. The primary star does not have detectable flare activity.{{citation|arxiv=1301.6192|title=An Ultraviolet Investigation of Activity on Exoplanet Host Stars|year=2013|doi=10.1088/0004-637X/766/1/9|last1=Shkolnik|first1=Evgenya L.|journal=The Astrophysical Journal|volume=766|issue=1|page=9|bibcode=2013ApJ...766....9S|s2cid=118415788}}

In 2014, a poorly characterized co-moving stellar companion HD 108863 B, likely a main sequence star of spectral class between F6 and G4, was discovered at a projected separation of 16.065 AU.{{cite journal |doi=10.1093/mnras/stu044 |title=New wide stellar companions of exoplanet host stars |year=2014 |last1=Mugrauer |first1=M. |last2=Ginski |first2=C. |last3=Seeliger |first3=M. |journal=Monthly Notices of the Royal Astronomical Society |volume=439 |issue=1 |pages=1063–1070 |bibcode=2014MNRAS.439.1063M |doi-access=free }}