23 Comae Berenices

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23 Comae Berenices
Observation data
Epoch J2000       Equinox J2000
Constellation Coma Berenices
Right ascension 12h 34m 51.08058s [1]
Declination +22° 37 45.3303 [1]
Apparent magnitude  (V)4.80 [2] (4.96 + 6.90) [3]
Characteristics
Spectral type A0IV [4]
U−B color index −0.01 [5]
B−V color index +0.012±0.015 [2]
Astrometry
Radial velocity (Rv)−16.0±1.8 [6]  km/s
Proper motion (μ)RA: −58.89 [1]   mas/yr
Dec.: 28.31 [1]   mas/yr
Parallax (π)10.52 ± 0.52  mas [1]
Distance 310 ± 20  ly
(95 ± 5  pc)
Absolute magnitude  (MV)−0.08 [2]
Orbit [7]
Period (P)33.04 yr
Semi-major axis (a)0.219″
Eccentricity (e)0.898
Inclination (i)109.7°
Longitude of the node (Ω)24.3°
Periastron epoch (T) B1964.62
Argument of periastron (ω)
(secondary)
214.5°
Details
Mass 2.15 [8]   M
Radius 3.0 [9]   R
Luminosity 104.00 [2]   L
Surface gravity (log g)3.85 [8]   cgs
Temperature 9,675±329 [8]   K
Rotational velocity (v sin i)40 [8]  km/s
Age 210 [8]   Myr
Other designations
23 Com, BD+23°2475, FK5  1323, GC  17142, HD  109485, HIP  61394, HR  4789, SAO  82390, WDS J12349+2238 [10]
Database references
SIMBAD data

23 Comae Berenices is a binary star [7] system in the northern constellation of Coma Berenices, situated a few degrees away from the North Galactic Pole. [11] It is visible to the naked eye as a faint, white-hued point of light with an apparent visual magnitude of 4.80. [2] The system is located around 310  light years away from the Sun, based on parallax. [1] It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s. [6]

The components of this system orbit each other with a period of 33 years, a large eccentricity of 0.9, and an angular semimajor axis of 0.219 . [7] The primary, designated component A, is a magnitude 4.96 [3] star with a stellar classification of A0IV, [4] matching an A-type subgiant that has exhausted the supply of hydrogen at its core and is in the process of evolving into a giant. Bychkov et al. (2009) list it as an Am star with an average field strength of 26×10−4  T . [12]

The primary is 210 [8]  million years old and is spinning with a projected rotational velocity of 40 km/s. [8] It has 2.15 [8] times the mass of the Sun and about three [9] times the Sun's radius. The star is radiating 104 [2] times the luminosity of the Sun from its photosphere at an effective temperature of 9,675 K. [8]

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References

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