Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation
Monoceros
Right ascension
07h 41m 14.832s[1]
Declination
−09° 33′ 04.078″[1]
Apparent magnitude (V)
3.94[2]
Characteristics
Spectral type
G9.5 III-IIIb Fe-0.5[3]
B−V color index
1.022[2]
Astrometry
Radial velocity (Rv)
+10.50[2] km/s
Proper motion (μ)
RA: -74.989 mas/yr[1] Dec.: -19.838 mas/yr[1]
Parallax (π)
22.3839 ± 0.1348 mas[1]
Distance
145.7 ± 0.9 ly (44.7 ± 0.3 pc)[1]
Absolute magnitude (MV)
0.71±0.08[4]
Details
Mass
1.78±0.11[5]M☉
Radius
10.05[5] – 10.42±0.12[6]R☉
Luminosity
63.7±1.3[6]L☉
Surface gravity (log g)
2.81±0.08[5] cgs
Temperature
5049±32[6] K
Metallicity [Fe/H]
−0.01±0.03[5] dex
Rotation
326 days[7]
Rotational velocity (v sin i)
1.9[7] km/s
Age
1.824±0.283[5] Gyr
Other designations
α Mon, 26 Monocerotis, BD−09° 2172, HD 61935, HIP 37447, HR 2970, SAO 134986[8]
Database references
SIMBAD
data
Alpha Monocerotis, Latinised from α Monocerotis, is the Bayer designation for the brightest star in the equatorial constellation of Monoceros. It can be viewed with the naked eye, having an apparent visual magnitude of 3.94.[2] Based upon an annual parallax shift of 22.4 mas as seen from Earth,[1] it is located 146 light-years away from the Sun. The star is moving away from the Sun with a radial velocity of +10.5 km/s.[2]
The stellar classification of G9.5 III-IIIb Fe-0.5[3] indicates this is an evolved giant star of type G, which means the hydrogen has been depleted at its core and the outer envelope has expanded and cooled. The 'Fe−0.5' notation indicates the spectrum displays a slight underabundance of iron relative to other stars of this temperature. It is a red clump giant, which means it is generating energy through helium fusion at its core.[9] At the age of 1.8 billion years, this yellow-hued star has an estimated two times the mass of the Sun and 10 times the Sun's radius.[5] It is spinning sedately with a rotation period of about 326 days.[7]
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AlphaMonocerotis, Latinised from α Monocerotis, is the Bayer designation for the brightest star in the equatorial constellation of Monoceros. It can...
see with the naked eye. AlphaMonocerotis has a visual magnitude of 3.93, while for Gamma Monocerotis it is 3.98. Beta Monocerotis is a triple star system;...
Ross 614 (V577 Monocerotis) is a red dwarf UV Ceti flare star and it is the primary member of a nearby binary star system in the constellation of Monoceros...
dwarf, WISE 0855−0714 (possibly a rogue planet). The closest system is Alpha Centauri, with Proxima Centauri as the closest star in that system, at 4...
O3.5 have subsequently been introduced. Spectral standards: O7V – S Monocerotis O9V – 10 Lacertae B-type stars are very luminous and blue. Their spectra...
a star in the Milky Way galaxy, flared similarly, and in 2002, V838 Monocerotis followed suit and was studied quite closely. The first confirmed luminous...
Nibiru cataclysm V838 Monocerotis, a variable star accompanied by a light echo, has been erroneously portrayed as an approaching planet or brown dwarf...
Frankowski, Adam; Joshi, Vishal; Menten, Karl M. (1 November 2021). "V838 Monocerotis as seen by ALMA: A remnant of a binary merger in a triple system". Astronomy...
helium opacity, but they are at a very different stage of their lives. Alpha Cygni (α Cyg) variables are nonradially pulsating supergiants of spectral...
first described by William Herschel. Herschel's Wonder Star is Beta Monocerotis. Hind's Crimson Star is R Leporis, a long-period variable star, named...
the whole envelope. V1309 Scorpii, a possible star merger. M31 RV V838 Monocerotis Ou 5, a planetary nebula whose progenitor was a common envelope binary...
"Rotation Statistics of Algol-Type Binaries and Results on RY Geminorum, RW Monocerotis, and RW Tauri", Astronomical Journal, 100: 1981, Bibcode:1990AJ....100...