Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Orion |
Right ascension | 05h 40m 50.71498s[1] |
Declination | −01° 07′ 43.6366″[1] |
Apparent magnitude (V) | 4.95[2] |
Characteristics | |
Spectral type | B2IV-V[3] or B3V[4] |
U−B color index | −0.83[5] |
B−V color index | −0.21[5] |
Astrometry | |
Radial velocity (Rv) | +26.10[6] km/s |
Proper motion (μ) | RA: −1.50[1] mas/yr Dec.: −0.84[1] mas/yr |
Parallax (π) | 3.63 ± 0.37[1] mas |
Distance | approx. 900 ly (approx. 280 pc) |
Absolute magnitude (MV) | −2.74[2] |
Orbit[7] | |
Period (P) | 27.154925 d |
Eccentricity (e) | 0.739±0.007 |
Periastron epoch (T) | 2447886.076±0.065 HJD |
Argument of periastron (ω) (secondary) | 81.4±2.4° |
Semi-amplitude (K1) (primary) | 84.7±1.1 km/s |
Details | |
A | |
Mass | 8.6±0.2[8] M☉ |
Luminosity | 4830[9] L☉ |
Temperature | 21,150[9] K |
Metallicity [Fe/H] | +0.01[10] dex |
Rotational velocity (v sin i) | 75[11] km/s |
Age | 18.0±3.2[8] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 37756 is a binary star system in the equatorial constellation of Orion, positioned less than a degree to the north of the bright star Alnitak.[13] It has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.95.[2] The system is located at a distance of approximately 900 light years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +26 km/s.[6] It is a member of the OB1b subgroup of the Orion OB1 Association.[14]
The binary nature of this system was identified by E. B. Frost in 1904.[15] It is a double-lined spectroscopic binary with an orbital period of 27.15 days and a high eccentricity of 0.74.[7] The spectrum matches a massive B-type main-sequence star with a stellar classification of B3V.[4] The secondary is luminous enough to interfere with measurements of the primary spectrum.[15] It is a suspected Cepheid variable with a period of 0.37968 days and an amplitude of 0.03 magnitude in the B band of the UBV photometric system.[16] The system is a candidate eclipsing binary with a minimum dip of 0.04 in visual magnitude during each orbit.[17]