Observation data Epoch J2000 Equinox J2000 | |
---|---|
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 mas [2] |
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]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
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 mas [2] |
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]