Astronomy:HD 108863

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Short description: Star in the constellation Coma Berenices
HD 108863
Observation data
Equinox J2000.0]] (ICRS)
Constellation Coma Berenices[1]
Right ascension  12h 30m 19.9098s[2]
Declination +21° 56′ 53.678″[2]
Apparent magnitude (V) 7.71[3]
Characteristics
Evolutionary stage red giant branch[2]
Spectral type K0III-IV[4]
B−V color index 0.99[5]
Astrometry
Radial velocity (Rv)−27.93±0.12[2] km/s
Proper motion (μ) RA: −75.278[2] mas/yr
Dec.: −33.577[2] mas/yr
Parallax (π)6.0246 ± 0.0233[2] mas
Distance541 ± 2 ly
(166.0 ± 0.6 pc)
Absolute magnitude (MV)+2.02[1]
Orbit[6]
PrimaryHD 108863
CompanionHD 108863 B
Semi-major axis (a)0.115"
(16.065 AU)
Details
Mass1.59[3] M☉
Radius5.74[3] R☉
Luminosity24.5[2] L☉
Surface gravity (log g)3.07 [3] cgs
Temperature4,878[3] K
Metallicity0.02[7]
Rotational velocity (v sin i)1.6±0.6[7] km/s
Age1.8±0.4[8] Gyr
Other designations
BD+22 2478, HD 108863, TYC 1447-2345-1, 2MASS J12301991+2156537[9]
Database references
SIMBADdata

HD 108863 is a giant star, the primary of a binary star system about 541 light-years away, belonging to spectral class K0. Its age is younger than the Sun's at 1.8±0.4 billion years. The primary star is slightly enriched in heavy elements, having 115% of solar abundance.[7] The primary star does not have detectable flare activity.[10]

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.[6]

Planetary system

In 2011 one superjovian planet, HD 108863 b, on a nearly circular orbit around star HD 108863 was discovered utilizing the radial velocity method.[5] The planet does not transit its host star.[3]

The HD 108863 planetary system[11]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b ≥2.6±0.2 MJ 1.40±0.03 443.4±4.2 <0.1 — —

References

  1. ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A  XHIP record for this object at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Luhn, Jacob K.; Bastien, Fabienne A.; Wright, Jason T.; Johnson, John A.; Howard, Andrew W.; Isaacson, Howard (2018), "Retired A Stars and Their Companions VIII: 15 New Planetary Signals Around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts", The Astronomical Journal 157 (4): 149, doi:10.3847/1538-3881/aaf5d0, Bibcode: 2019AJ....157..149L 
  4. ↑ Yoss, K. M.; Griffin, R. F. (September 1997), "Radial Velocities and DDO, BV Photometry of Henry Draper G5-M Stars Near the North Galactic Pole", Journal of Astrophysics and Astronomy 18 (2–3): 161, doi:10.1007/BF02714877, Bibcode: 1997JApA...18..161Y. 
  5. ↑ 5.0 5.1 John Asher Johnson; Clanton, Christian; Howard, Andrew W.; Bowler, Brendan P.; Henry, Gregory W.; Marcy, Geoffrey W.; Crepp, Justin R.; Endl, Michael et al. (2011), "Retired a Stars and Their Companions. Vii. 18 New Jovian Planets", The Astrophysical Journal Supplement Series 197 (2): 26, doi:10.1088/0067-0049/197/2/26, Bibcode: 2011ApJS..197...26J 
  6. ↑ 6.0 6.1 Mugrauer, M.; Ginski, C.; Seeliger, M. (2014). "New wide stellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society 439 (1): 1063–1070. doi:10.1093/mnras/stu044. Bibcode: 2014MNRAS.439.1063M. 
  7. ↑ 7.0 7.1 7.2 Ghezzi, Luan; Montet, Benjamin T.; Johnson, John Asher (2018), "Retired a Stars Revisited: An Updated Giant Planet Occurrence Rate as a Function of Stellar Metallicity and Mass", The Astrophysical Journal 860 (2): 109, doi:10.3847/1538-4357/aac37c, Bibcode: 2018ApJ...860..109G 
  8. ↑ Bonsor, Amy; Kennedy, Grant M.; Wyatt, Mark C.; Johnson, John A.; Sibthorpe, Bruce (2013), "Herschel Observations of Debris Discs Orbiting Planet-hosting Subgiants", Monthly Notices of the Royal Astronomical Society 437 (4): 3288–3297, doi:10.1093/mnras/stt2128 
  9. ↑ "HD 108863". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+108863. 
  10. ↑ Shkolnik, Evgenya L. (2013), "An Ultraviolet Investigation of Activity on Exoplanet Host Stars", The Astrophysical Journal 766 (1): 9, doi:10.1088/0004-637X/766/1/9, Bibcode: 2013ApJ...766....9S 
  11. ↑ Planet HD 108863 b on exoplanet.eu

Coordinates: Sky map 12h 30m 19.9101s, +21° 56′ 53.6794″