Observation data Equinox J2000.0]] (ICRS) | |
---|---|
Constellation | Canes Venatici |
Right ascension | 12h 23m 47.01149s[2] |
Declination | +42° 32′ 33.8670″[2] |
Apparent magnitude (V) | +6.04[3] 5.89 to 6.15[4] |
Characteristics | |
Spectral type | F3 IV[5] or F0 III[6] |
B−V color index | 0.366±0.005[7] |
Variable type | δ Sct[8] |
Astrometry | |
Radial velocity (Rv) | −0.3±2.9[3] km/s |
Proper motion (μ) | RA: −79.651[2] mas/yr Dec.: +13.203[2] mas/yr |
Parallax (π) | 7.6829 ± 0.0960[2] mas |
Distance | 425 ± 5 ly (130 ± 2 pc) |
Absolute magnitude (MV) | +0.75[9] |
Orbit[3] | |
Period (P) | 124.44±0.03 d |
Eccentricity (e) | 0.311±0.003 |
Periastron epoch (T) | 2454605±10.3 JD |
Argument of periastron (ω) (secondary) | 70.2±0.7° |
Semi-amplitude (K1) (primary) | 13.24±0.05 km/s |
Details[3] | |
4 CVn A | |
Mass | 1.0–2.0 M☉ |
Radius | 3.7–4.1 R☉ |
Luminosity | 295+3.6 −3.2 L☉ |
Surface gravity (log g) | 3.30±0.35 cgs |
Temperature | 6,875±120 K |
Metallicity [Fe/H] | −0.05±0.15 dex |
Rotational velocity (v sin i) | 109±3 km/s |
Other designations | |
Database references | |
SIMBAD | data |
4 Canum Venaticorum is a binary star system in the northern constellation of Canes Venatici, located around 425 light years away.[2] It has the variable star designation AI Canum Venaticorum; 4 Canum Venaticorum is its Flamsteed designation. Its brightness varies from magnitude +5.89 to +6.15 with a period of 2.8 hours,[4] which places it around the lower limit of visibility to the naked eye. This was found to be a binary by Schmid et al. in 2014, based on periodic, non-sinusoidal changes in its radial velocity. It is a single-lined spectroscopic binary with an orbital period of 124.4 days and an eccentricity of 0.31.[3]
The primary component is an evolved F-type star with a stellar classification of F3 IV[5] or F0 III,[6] matching a subgiant or giant star, respectively. It is a variable of the Delta Scuti class, displaying both radial and non-radial pulsations.[8] The variable nature of this star was discovered by D. H. P. Jones and C. Margaret Haslam in 1966 at the suggestion of Olin J. Eggen,[11] and it has become one of the best studied stars in its class. The radial pulsations have shown little if any variations between 1974 and 2012. However, the non-radial pulsations vary continuously in frequency over periods spanning decades.[8] It is spinning rapidly with a rotation of at least one third of its critical velocity.[3]
Original source: https://en.wikipedia.org/wiki/4 Canum Venaticorum.
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