Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Orion |
Right ascension | 05h 38m 53.08332s[1] |
Declination | −07° 12′ 46.1667″[1] |
Apparent magnitude (V) | 4.80[2] |
Characteristics | |
Evolutionary stage | main sequence |
Spectral type | A4Vn[3] |
U−B color index | +0.11[2] |
B−V color index | +0.13[2] |
Astrometry | |
Radial velocity (Rv) | −5.30[4] km/s |
Proper motion (μ) | RA: −15.562[1] mas/yr Dec.: −50.613[1] mas/yr |
Parallax (π) | 23.1346 ± 0.2801 mas[1] |
Distance | 141 ± 2 ly (43.2 ± 0.5 pc) |
Absolute magnitude (MV) | 1.52[5] |
Details | |
Mass | 1.78[6] M☉ |
Radius | 2.0[7] R☉ |
Luminosity | 22[8] L☉ |
Surface gravity (log g) | 4.06[6] cgs |
Temperature | 8,416±286[6] K |
Rotational velocity (v sin i) | 186[8] km/s |
Age | 284[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
49 Orionis is a single[10] star in the equatorial constellation of Orion. It has the Bayer designation d Orionis, while 49 Orionis is the Flamsteed designation. This object is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.80.[2] It is located 141 light years away from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −5 km/s.[4]
In the past 49 Orionis was reported as a spectroscopic binary and an orbit was computed with a period of 445.74 days and an eccentricity of 0.549.[11] But it was later determined to be single.[10]
This object is an A-type main-sequence star with a stellar classification of A4Vn,[3] where the 'n' suffix indicates broadened "nebulous" lines caused by rapid rotation. It is around 284[6] million years old with a projected rotational velocity of 186 km/s.[8] This spin is giving the star an oblate shape with an equatorial bulge that is an estimated 8% larger than the polar radius.[12] The star has 1.8[6] times the mass of the Sun and double[7] the Sun's radius. It is radiating 22[8] times the Sun's luminosity from its photosphere at an effective temperature of 8,416 K.[6]