Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Columba |
Right ascension | 05h 57m 32.20958s[1] |
Declination | −35° 16′ 59.8153″[1] |
Apparent magnitude (V) | 4.366 + 12.664[2] |
Characteristics | |
Spectral type | B2.5 IV[3] + G8 V[4] |
U−B color index | −0.66[5] |
B−V color index | −0.18[5] |
Variable type | Candidate SPB[6] |
Astrometry | |
Radial velocity (Rv) | +24.2[7] km/s |
Proper motion (μ) | RA: −3.24[1] mas/yr Dec.: +10.21[1] mas/yr |
Parallax (π) | 3.75 ± 0.18 mas[1] |
Distance | 870 ± 40 ly (270 ± 10 pc) |
Absolute magnitude (MV) | −2.76[8] |
Details[6] | |
γ Col A | |
Mass | 5.7±0.3 M☉ |
Radius | 4.8±0.4 R☉ |
Luminosity | 2,070[9] L☉ |
Surface gravity (log g) | 3.328±0.100[10] cgs |
Temperature | 15570±320[10] K |
Rotational velocity (v sin i) | 96±16 km/s |
Age | 23.6±2.0[11] Myr |
γ Col B | |
Mass | 0.94[2] M☉ |
Temperature | 5,367[2] K |
Other designations | |
Database references | |
SIMBAD | data |
Gamma Columbae, Latinized from γ Columbae, is a possible wide binary star system[2] in the southern constellation of Columba. It is visible to the naked eye with an apparent visual magnitude of 4.36.[5] Based upon an annual parallax shift of 3.75 mas,[1] it is located roughly 870 light years from the Sun.
The primary component is an evolved[6] B-type subgiant star with a stellar classification of B2.5 IV.[3] It is a candidate slowly pulsating B-type star with a mean longitudinal magnetic field strength of 94±28 G.[6] The star has nearly six times the mass of the Sun and close to five times the Sun's girth.[6] It is radiating over 2,000 times the solar luminosity from its outer atmosphere at an effective temperature of 12,904 K.[9] The estimated age of this star is around 24 million years.[11] At this age, it is thought to be the remnant of a once more massive star that just finished hydrogen fusion, and is undergoing structural readjustment. This process is extremely short, on the order of ten thousand years, making it a rare object.[10]
The visual magnitude 12.664[2] companion is a G-type main sequence star with a classification of G8 V.[4] It lies at an angular separation of 33.8 arc seconds from the primary, which corresponds to a projected physical separation of 8,844 AU.[2] Despite the young age of these stars, there has been no X-ray emission detected.[2]