Delta Orionis
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| Observation data Epoch J2000 |
|
|---|---|
| Constellation | Orion |
| Right ascension | 05h 32m 00.4s |
| Declination | −00° 17′ 57″ |
| Apparent magnitude (V) | 2.23(3.2/3.3) / 6.85 / 14.0 |
| Spectral Characteristics | |
| Spectral type | O9.5 II / B2 V |
| U-B color index | −1.05 |
| B-V color index | −0.22 |
| Variable type | Eclipsing binary |
| Astrometry | |
| Radial velocity (Rv) | 16 km/s |
| Proper motion (μ) | RA: 1.67 mas/yr Dec.: 0.46 mas/yr |
| Parallax (π) | 3.56 ± 0.83 mas |
| Distance | approx. 900 ly (approx. 280 pc) |
| Absolute magnitude (MV) | −4.99 |
| Other designations | |
| Database references | |
| SIMBAD | data |
Delta Orionis (δ Ori) is one of the three stars of the belt of the constellation Orion. It also has the traditional name Mintaka (from منطقة manţaqah, which means "belt" in Arabic).
Mintaka is actually a multiple star with a magnitude 7 star about 52" away from the main component and an even fainter star in between. The main component itself is also double, consisting of a class B giant and a smaller but hotter class O. The stars orbit each other every 5.73 days. These two stars are both about 70,000 times as luminous as the Sun with a mass of some 20 solar masses.
In 1904, Johannes Hartmann discovered that interstellar space contains a thin gas, by using Mintaka as a background source (see interstellar medium).
