Xi Coronae Borealis

Xi Coronae Borealis (ξ CrB) is a binary star^[8] system in the northern constellation of Corona Borealis. It is visible to the naked eye with a combined apparent visual magnitude of 4.85.^[2] Based upon an annual parallax shift of 17.78 mas as seen from the Earth,^[1] it is located about 183 light years from the Sun.

ξ Coronae Borealis

Location of ξ Coronae Borealis (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Corona Borealis
Right ascension	16h 22m 05.82391s[1]
Declination	+30° 53′ 31.1837″[1]
Apparent magnitude (V)	4.85[2]
Characteristics
Evolutionary stage	red clump[3]
Spectral type	G9 IIIFe−0.5[4]
U−B color index	+0.80[2]
B−V color index	+0.97[2]
Astrometry
Radial velocity (Rv)	−29.20±0.16[5] km/s
Proper motion (μ)	RA: −97.43[1] mas/yr Dec.: +107.45[1] mas/yr
Parallax (π)	17.78±0.25 mas[1]
Distance	183 ± 3 ly (56.2 ± 0.8 pc)
Absolute magnitude (MV)	+1.04[6]
Details[5]
Mass	2.36[6] M☉
Radius	8 R☉
Luminosity	36 L☉
Surface gravity (log g)	2.9 cgs
Temperature	4,853±5 K
Metallicity [Fe/H]	−0.08 dex
Rotational velocity (v sin i)	2.8 km/s
Age	676[6] Myr
Other designations
ξ CrB, 19 CrB, BD+31°2845, HD 147677, HIP 80181, HR 6103, SAO 65254, WDS J16221+3054A[7]
Database references
SIMBAD	data

As of 2009, the pair had an angular separation of 91 mas along a position angle of 139.4°.^[9] The brighter member, component Aa,^[9] is an evolved G-type giant star with a stellar classification of G9 III. It is a red clump star that is generating energy by helium fusion at its core.^[3] The star has an estimated 2.36 times the mass of the Sun and has expanded to 8 times the Sun's radius. It is radiating 36 times the solar luminosity from its photosphere at an effective temperature of 4,853 K.^[5]