25 Canum Venaticorum

25 Canum Venaticorum
Observation data
Epoch J2000      Equinox J2000
Constellation Canes Venatici
Right ascension 13h 37m 27.62782s
Declination +36° 17 41.6337
Apparent magnitude (V) +4.82 (4.98 + 6.95)
Characteristics
Spectral type A7 III + A8 V:
Astrometry
Radial velocity (Rv)−10.4±2.1 km/s
Proper motion (μ) RA: −95.54 mas/yr
Dec.: +23.75 mas/yr
Parallax (π)16.42±0.53 mas
Distance199 ± 6 ly
(61 ± 2 pc)
Absolute magnitude (MV)0.90
Orbit
Period (P)228 yr
Semi-major axis (a)1.02″
Eccentricity (e)0.80
Inclination (i)147°
Longitude of the node (Ω)87°
Periastron epoch (T)1864.0
Argument of periastron (ω)
(secondary)
159°
Details
25 CVn A
Mass2.23 M
Surface gravity (log g)3.85 cgs
Temperature7,609±259 K
Rotational velocity (v sin i)235 km/s
Age659 Myr
25 CVn B
Mass1.58 M
Other designations
25 CVn, BD+37°2433, FK5 3083, GC 18421, HD 118623, HIP 66458, HR 5127, SAO 63648, ADS 8974, CCDM 13375+3617, WDS J13375+3618
Database references
SIMBADdata

25 Canum Venaticorum is a binary star system in the northern constellation of Canes Venatici, approximately 199 light years from the Sun. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of +4.82 The system is moving closer to the Earth with a heliocentric radial velocity of roughly −10 km/s.

This is a wide binary system with an orbital period of 228 years and an eccentricity of 0.80. As of 2001, they had a projected separation of 107.0 AU. The magnitude 4.98 primary, component A, has a stellar classification of A7 III, which matches an A-type giant star. It is 659 million years old with a projected rotational velocity of 235 km/s. This rate of spin is giving the star an oblate shape with an equatorial bulge that is an estimated 27% larger than the polar radius. The companion, component B, is a magnitude 6.95 A-type main-sequence star with a class of A8 V:. The ':' suffix indicates some uncertainty in the classification of this star.