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. Bibcode2012AstL...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, Bibcode2019AJ....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, Bibcode1997JApA...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, Bibcode2011ApJS..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. Bibcode2014MNRAS.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, Bibcode2018ApJ...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, Bibcode2013ApJ...766....9S 
  11. Planet HD 108863 b on exoplanet.eu

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