4 Canum Venaticorum

4 Canum Venaticorum

A light curve for AI Canes Venaticorum, plotted from TESS data[1]
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]
Distance425 ± 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
Mass1.0–2.0 M☉
Radius3.7–4.1 R☉
Luminosity295+3.6
−3.2 L☉
Surface gravity (log g)3.30±0.35 cgs
Temperature6,875±120 K
Metallicity [Fe/H]−0.05±0.15 dex
Rotational velocity (v sin i)109±3 km/s
Other designations
4 CVn, AI Canum Venaticorum, BD+43°2218, FK5 2993, GC 16899, HD 107904, HIP 60467, HR 4715, SAO 44155[10]
Database references
SIMBADdata

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]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Schmid2014 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Morgan1972 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Appenzeller1967 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Breger2017 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Eggen1998 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Jones1966 was invoked but never defined (see the help page).