Xi2 Canis Majoris, which is Latinized from ξ2 Canis Majoris, is an astrometric binary[4] star system in the southern constellation of Canis Major. With an apparent visual magnitude of +4.54,[2] it is visible to the naked eye. Based upon an annual parallax shift of 8.35 mas,[1] the system is approximately 390 light years distant from Earth. It is receding with a radial velocity of +26 km/s.[6]
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Canis Major |
Right ascension | 06h 35m 03.38859s[1] |
Declination | −22° 57′ 53.2913″[1] |
Apparent magnitude (V) | +4.54[2] |
Characteristics | |
Spectral type | A0 V[3][4] or A0 III[5] |
U−B color index | −0.01[2] |
B−V color index | −0.06[2] |
Astrometry | |
Radial velocity (Rv) | +26.0±4.2[6] km/s |
Proper motion (μ) | RA: +15.437[1] mas/yr Dec.: +18.682[1] mas/yr |
Parallax (π) | 8.3465 ± 0.2721 mas[1] |
Distance | 390 ± 10 ly (120 ± 4 pc) |
Absolute magnitude (MV) | +0.94[7] |
Details | |
Radius | 2.7[8] R☉ |
Luminosity | 224[9] L☉ |
Temperature | 8,799[9] K |
Rotational velocity (v sin i) | 145[10] km/s |
Age | 339[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
The binary nature of this system was determined based on changes in the proper motion of the visible component.[12] Buscombe (1962) gave the white-hued primary a stellar classification of A0 V,[3] indicating it is an A-type main-sequence star. However, Houk and Smith-Moore (1978) list it with a class of A0 III,[5] which would match a more evolved giant star, also of the A-type. It is 339[7] million years old with a high rate of spin, having a projected rotational velocity of 145 km/s.[10] The star is radiating 224[9] times the Sun's luminosity from its photosphere at an effective temperature of 8,799 K.[9]