69 Orionis
Star in the constellation Orion
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69 Orionis is a single[11] star in the equatorial constellation of Orion, positioned a couple of degrees to the north of Xi Orionis. It has the Bayer designation f1 Orionis; 69 Orionis is the Flamsteed designation. The star is visible to the naked eye as faint, blue-white hued point of light with an apparent visual magnitude of 4.92.[2] It is located approximately 530 light-years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +22 km/s.[4] In 2015, H. Bouy and J. Alves suggested that it is a member of the newly discovered Taurion OB association.[9]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Orion |
| Right ascension | 06h 12m 03.27955s[1] |
| Declination | +16° 07′ 49.4614″[1] |
| Apparent magnitude (V) | 4.92[2] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | B5Vn[3] |
| U−B color index | −0.59[2] |
| B−V color index | −0.12[2] |
| Astrometry | |
| Radial velocity (Rv) | +22.00[4] km/s |
| Proper motion (μ) | RA: +5.49[1] mas/yr Dec.: −16.80[1] mas/yr |
| Parallax (π) | 6.17±0.25 mas[1] |
| Distance | 530 ± 20 ly (162 ± 7 pc) |
| Absolute magnitude (MV) | −1.09[5] |
| Details[6] | |
| Mass | 6.4±0.2 M☉ |
| Radius | 3.4[7] R☉ |
| Luminosity | 1,442+248 −212 L☉ |
| Surface gravity (log g) | 4.05±0.17 cgs |
| Temperature | 17,090 K |
| Metallicity [Fe/H] | +0.01[8] dex |
| Rotational velocity (v sin i) | 285±23 km/s |
| Age | 10–40[9] Myr |
| Other designations | |
| f1 Ori, 69 Ori, BD+16°1035, GC 7891, HD 42545, HIP 29434, HR 2198, SAO 95365[10] | |
| Database references | |
| SIMBAD | data |
This object is a B-type main-sequence star with a stellar classification of B5Vn,[3] where the 'n' suffix indicates "nebulous" (broad) lines due to rapid rotation. It has a projected rotational velocity of 285 km/s, compared to a critical velocity of 476±37 km/s; the polar axis is inclined by 64°±16°.[6] This is a known Be star[12] that began behaving as a normal star in November, 1982.[13] It has 6.4 times the mass of the Sun and is radiating around 1,442 times the Sun's luminosity from its photosphere at an effective temperature of 17,090 K.[6]