γ Monocerotis, Latinised as Gamma Monocerotis, is a binary star[8] system in the equatorial constellation of Monoceros. Based upon an annual parallax shift of 6.55 mas,[1] it is located roughly 500 light years from the Sun. It can be viewed with the naked eye, having an apparent visual magnitude of 3.96.[2] Gamma Monocerotis is moving away from the Sun with a radial velocity of −5 km/s.[4]
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Monoceros |
Right ascension | 06h 14m 51.33367s[1] |
Declination | −06° 16′ 29.1880″[1] |
Apparent magnitude (V) | 3.96[2] |
Characteristics | |
Spectral type | K1.5IIIBa0.3[3] |
U−B color index | +1.42[2] |
B−V color index | +1.31[2] |
Astrometry | |
Radial velocity (Rv) | −4.8±0.7[4] km/s |
Proper motion (μ) | RA: −4.69[1] mas/yr Dec.: −19.30[1] mas/yr |
Parallax (π) | 6.55 ± 0.19 mas[1] |
Distance | 500 ± 10 ly (153 ± 4 pc) |
Absolute magnitude (MV) | -1.93[5] |
Details | |
Luminosity | 1021[5] L☉ |
Surface gravity (log g) | 1.61[6] cgs |
Temperature | 4,375[6] K |
Metallicity [Fe/H] | −0.15[6] dex |
Rotational velocity (v sin i) | 4.0[7] km/s |
Other designations | |
Database references | |
SIMBAD | data |
This is an evolved K-type giant star with a stellar classification of K1.5 III Ba0.3.[3] The Ba0.3 suffix indicates this is a mild barium star, which means the spectrum displays abnormal abundance of s-process elements, including barium. These were deposited by an orbiting companion as it passed through the asymptotic giant branch stage. The companion is now a white dwarf star.[9]
It has reported companions B, at separation 53.7" and magnitude 13.1, and C, at separation 47.9" and magnitude 13.6.[10]