{{Short description|Star in the constellation Coma Berenices}} {{Starbox begin | name = HD 108863 }} {{Starbox observe | epoch = J2000 | constell = [[Coma Berenices]]<ref name=xhip/> | ra = {{RA|12|30|19.9098}}<ref name=dr3/> | dec = {{DEC|+21|56|53.678}}<ref name=dr3/> | appmag_v = 7.71<ref name=Luhn2018>{{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 }}</ref> }} {{Starbox character | type = [[red giant branch]]<ref name=dr3/> | class = K0III-IV<ref name=Yoss1997/> | b-v = 0.99<ref name=Johnson2011/> | variable = }} {{Starbox astrometry | radial_v = {{val|−27.93|0.12}}<ref name=dr3/> | prop_mo_ra = −75.278<ref name=dr3/> | prop_mo_dec = −33.577<ref name=dr3/> | parallax = 6.0246 | p_error = 0.0233 | parallax_footnote = <ref name=dr3/> | absmag_v = +2.02<ref name=xhip/> }} {{Starbox orbit | reference = <ref name=Mugrauer2014/> | primary = HD 108863 | name = HD 108863 B | period = <!--Period (in years)--> | period_unitless = <!--Period (no units provided by template)--> | axis = 0.115 | axis_unitless = 16.065 [[astronomical unit|AU]] | eccentricity = <!--Eccentricity--> | inclination = <!--Inclination (in degrees)--> | node = <!--Longitude of node (in degrees)--> | periastron = <!--Periastron epoch--> | periarg = <!--Argument of periastron (in degrees), secondary --> | periarg_primary = <!--Argument of periastron (in degrees), primary --> | k1 = <!-- Velocity semi-amplitude (SB1, or primary in SB2), in km/s --> | k2 = <!-- Velocity semi-amplitude (secondary in SB2), in km/s --> }} {{Starbox detail | mass = 1.59<ref name=Luhn2018/> | radius = 5.74<ref name=Luhn2018/> | gravity = 3.07 <ref name=Luhn2018/> | luminosity = 24.5<ref name=dr3/> | temperature = 4,878<ref name=Luhn2018/> | metal = 0.02<ref name=Ghezzi2018>{{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 }}</ref> | rotation = | rotational_velocity = {{val|1.6|0.6}}<ref name=Ghezzi2018/> | age_gyr = {{val|1.8|0.4}}<ref name=Bonsor2013>{{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}}</ref> }} {{Starbox catalog | names = {{odlist|HD=108863|BD=+22 2478|2MASS=J12301991+2156537|TYC=1447-2345-1}}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = HD+108863 }} {{Starbox end}}
'''HD 108863''' is a [[giant star]], the primary of a binary star system about {{val|541|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.<ref name=Ghezzi2018/> The primary star does not have detectable flare activity.<ref>{{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}}</ref>
In 2014, a poorly characterized co-moving stellar companion HD 108863 B, likely a [[Main sequence|main sequence star]] of spectral class between F6 and G4, was discovered at a projected separation of 16.065 [[astronomical unit|AU]].<ref name=Mugrauer2014>{{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 }}</ref>
==Planetary system== In 2011 one [[super-jupiter|superjovian]] planet, HD 108863 b, on a nearly circular orbit around star HD 108863 was discovered utilizing the [[radial velocity method]].<ref name=Johnson2011>{{citation|arxiv=1108.4205|year=2011|doi=10.1088/0067-0049/197/2/26|author1=John Asher Johnson|last2=Clanton|first2=Christian|last3=Howard|first3=Andrew W.|last4=Bowler|first4=Brendan P.|last5=Henry|first5=Gregory W.|last6=Marcy|first6=Geoffrey W.|last7=Crepp|first7=Justin R.|last8=Endl|first8=Michael|last9=Cochran|first9=William D.|last10=MacQueen|first10=Phillip J.|last11=Wright|first11=Jason T.|last12=Isaacson|first12=Howard|title=Retired a Stars and Their Companions. Vii. 18 New Jovian Planets|journal=The Astrophysical Journal Supplement Series|volume=197|issue=2|page=26|bibcode=2011ApJS..197...26J|s2cid=15088371}}</ref> The planet does not transit its host star.<ref name=Luhn2018/> {{OrbitboxPlanet begin | table_ref = <ref name=exoplanet>[https://exoplanet.eu/catalog/hd_108863_b--904/ Planet HD 108863 b on exoplanet.eu]</ref> }} {{OrbitboxPlanet | exoplanet = b | mass = {{val|2.6|0.2|p=≥}} | radius = | semimajor = {{val|1.40|0.03}} | period = {{val|443.4|4.2}} | eccentricity = <0.1 | inclination = }} {{Orbitbox end}}
==References== <references> <ref name=SIMBAD>{{cite simbad|title=HD 108863|access-date = 20 October 2020}}</ref>
<ref name=dr3>{{cite Gaia DR3|3952692457305436800}}</ref>
<ref name=xhip>{{cite XHIP|61020}}</ref>
<ref name=Yoss1997>{{citation | title=Radial Velocities and DDO, BV Photometry of Henry Draper G5-M Stars Near the North Galactic Pole | last1=Yoss | first1=K. M. | last2=Griffin | first2=R. F. | journal=Journal of Astrophysics and Astronomy | volume=18 | page=161 | date=September 1997 | issue=2–3 | postscript=. | doi=10.1007/BF02714877 | bibcode=1997JApA...18..161Y | s2cid=123221180 }}</ref> </references>
{{Sky|12|30|19.9101|+|21|56|53.6794}}
{{Coma Berenices}}
{{DEFAULTSORT:HD 108863}} [[Category:Coma Berenices]] [[Category:Planetary systems with one confirmed planet]] [[Category:Hipparcos objects|061020]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|108863]] [[Category:Binary stars]] [[Category:K-type giants]] [[Category:Population I stars]]