Omega Fornacis
Binary star system in the constellation Fornax
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Omega Fornacis, which is Latinized from ω Fornacis, is a wide binary star[11] system in the southern constellation of Fornax. It has a blue-white hue and is faintly visible to the naked eye as a fifth-magnitude star.[6] The system lies at a distance of approximately 470 light years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +10 km/s.[6]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Fornax |
| Right ascension | 02h 33m 50.70081s[1] |
| Declination | −28° 13′ 56.3890″[1] |
| Apparent magnitude (V) | 4.95 + 7.71[2] |
| Characteristics | |
| A | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B9V[4] |
| U−B color index | −0.13[5] |
| B−V color index | −0.050±0.007[6] |
| R−I color index | −0.07[5] |
| B | |
| Spectral type | A3V[7] |
| U−B color index | +0.09[8] |
| B−V color index | +0.17[8] |
| Astrometry | |
| Radial velocity (Rv) | +9.7±2.8[6] km/s |
| Proper motion (μ) | RA: −13.290±0.243[1] mas/yr Dec.: −5.532±0.305[1] mas/yr |
| Parallax (π) | 7.0025±0.1527 mas[1] |
| Distance | 470 ± 10 ly (143 ± 3 pc) |
| Absolute magnitude (MV) | −0.87[6] |
| Details | |
| A | |
| Mass | 3.42±0.11[3] M☉ |
| Radius | 2.81[7] R☉ |
| Luminosity | 268+72 −57[3] L☉ |
| Temperature | 10,910±420[9] K |
| Rotational velocity (v sin i) | 85±13[7] km/s |
| B | |
| Radius | 2.2[7] R☉ |
| Rotational velocity (v sin i) | 180±29[7] km/s |
| Other designations | |
| ω For, CD−28°819, HD 16046, HIP 11918, HR 749, SAO 167882, CCDM J02338-2814AB, WDS J02338-2814[10] | |
| Database references | |
| SIMBAD | data |
The dual nature of this system was discovered in 1836 by John Herschel. As of 2013, the two components had an angular separation of 11.0″ along a position angle of 246°.[2] This corresponds to a projected separation of 1,520 AU.[7]
The magnitude 4.95[2] primary, designated component A, is a chemically peculiar[3] B-type main-sequence star with a stellar classification of B9V[4] It has 3.4[3] times the Sun's mass and is radiating around 268[3] times the luminosity of the Sun from its photosphere at an effective temperature of 10,910 K.[9] Component B, the magnitude 7.71[2] secondary, is an A-type main-sequence star with a class of A3V.[7] It is smaller than the primary, but has a higher projected rotational velocity.[7]