Nu Orionis (ν Orionis) is a binary star[11] system in the northeastern part of the constellation Orion. It should not be confused with the variable star NU Orionis.[12] Nu Orionis has an apparent visual magnitude of 4.42,[2] which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 0.00632 arcseconds,[1] the distance to this system is roughly 520 light years.
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Orion |
Right ascension | 06h 07m 34.32588s[1] |
Declination | +14° 46′ 06.5061″[1] |
Apparent magnitude (V) | 4.42[2] |
Characteristics | |
Spectral type | B3 V[3] or B3 IV[4] |
U−B color index | −0.67[2] |
B−V color index | −0.18[2] |
Astrometry | |
Radial velocity (Rv) | +24.1[5] km/s |
Proper motion (μ) | RA: +6.78[1] mas/yr Dec.: −20.23[1] mas/yr |
Parallax (π) | 6.32 ± 0.33 mas[1] |
Distance | 520 ± 30 ly (158 ± 8 pc) |
Orbit[6] | |
Period (P) | 131.211 d |
Eccentricity (e) | 0.64 |
Periastron epoch (T) | 2436475.852 JD |
Argument of periastron (ω) (secondary) | 6.6° |
Semi-amplitude (K1) (primary) | 33.3 km/s |
Details | |
ν Ori A | |
Mass | 6.7±0.1[4] M☉ |
Radius | 4.3[7] R☉ |
Luminosity | 1,965[3] L☉ |
Surface gravity (log g) | 4.06[8] cgs |
Temperature | 17,880[8] K |
Metallicity [Fe/H] | −0.05[8] dex |
Rotational velocity (v sin i) | 30[9] km/s |
Age | 26.3±5.3[4] Myr |
Other designations | |
Database references | |
SIMBAD | data |
This is a single-lined spectroscopic binary system,[9] which means that only the absorption line features of one of the components can be distinguished. The components orbit each other with a period of 131.2 days and an eccentricity of 0.64.[6] Depending on the source, the primary is either a B-type main sequence star with a stellar classification of B3 V,[3] or a more evolved B-type subgiant star of class B3 IV.[4] It has an angular diameter of 0.251 mas,[13] which, at the estimated distance of this system, yields a physical size of about 4.3 times the radius of the Sun.[7] The mass is 6.7[4] times that of the Sun and it shines with 1,965[3] times the solar luminosity from its outer atmosphere at an effective temperature of 17,880 K.[8]