Delta Columbae
Binary star system in the constellation Columba
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Delta Columbae is a binary star system in the constellation Columba. It can be seen with the naked eye having an apparent visual magnitude of 3.85.[3] The distance to this system, based upon an annual parallax shift of 13.94 mas,[2] is around 234 lightyears.
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Columba[1] |
| Right ascension | 06h 22m 06.82831s[2] |
| Declination | −33° 26′ 11.0323″[2] |
| Apparent magnitude (V) | 3.85[3] |
| Characteristics | |
| Spectral type | G7 II[4] |
| U−B color index | +0.52[3] |
| B−V color index | +0.88[3] |
| Astrometry | |
| Proper motion (μ) | RA: −24.23[2] mas/yr Dec.: −51.40[2] mas/yr |
| Parallax (π) | 13.94±0.51 mas[2] |
| Distance | 234 ± 9 ly (72 ± 3 pc) |
| Absolute magnitude (MV) | −0.32[5] |
| Orbit[6][7] | |
| Period (P) | 868.78 d |
| Semi-major axis (a) | 9.02±0.52 mas |
| Eccentricity (e) | 0.7 |
| Inclination (i) | 116.3±4.2° |
| Periastron epoch (T) | 2419915.02 JD |
| Argument of periastron (ω) (secondary) | 117.1° |
| Semi-amplitude (K1) (primary) | 10.6 km/s |
| Details | |
| δ Col A | |
| Luminosity | 149.5[8] L☉ |
| Surface gravity (log g) | 2.49[9] cgs |
| Temperature | 5,136[5] K |
| Metallicity [Fe/H] | −0.04[9] dex |
| Rotational velocity (v sin i) | 4.8±0.2[5] km/s |
| Other designations | |
| δ Col, CD−33°2927, HD 44762, HIP 30277, HR 2296, SAO 196735.[10] | |
| Database references | |
| SIMBAD | data |
Delta Columbae was a latter designation of 3 Canis Majoris, as the early astronomers Johann Bayer and John Flamsteed did not include the constellation Columba in their star charts.[11]
This is a single-lined spectroscopic binary system with an orbital period of 868.78 days and an eccentricity of 0.7.[6] It has a peculiar velocity of 30.2±3.9 km/s, making it a candidate runaway star system. The primary component is a G-type bright giant star with a stellar classification of G7 II.[4] It radiates around 149[8] time the solar luminosity from its outer atmosphere at an effective temperature of 5,136 K.[5]