Gamma Muscae

γ Muscae, Latinised as Gamma Muscae, is a blue-white hued star in the southern circumpolar constellation of Musca, the Fly. It can be seen with the naked eye, having an apparent visual magnitude of 3.87.^[2] Based upon an annual parallax shift of 10.04 mas as seen from Earth, it is located about 325 light years from the Sun.

A light curve for Gamma Muscae, plotted from TESS data^[7]

γ Muscae

Location of γ Muscae (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Musca
Right ascension	12h 32m 28.01343s[1]
Declination	−72° 07′ 58.7597″[1]
Apparent magnitude (V)	3.87[2]
Characteristics
Spectral type	B5 V[3]
U−B color index	−0.61[2]
B−V color index	−0.15[2]
Variable type	SPB
Astrometry
Radial velocity (Rv)	2.5±7.4[4] km/s
Proper motion (μ)	RA: −51.34[1] mas/yr Dec.: −5.40[1] mas/yr
Parallax (π)	10.04±0.13 mas[1]
Distance	325 ± 4 ly (100 ± 1 pc)
Absolute magnitude (MV)	−1.1[5]
Details
Mass	5.09[6] M☉
Radius	4.17[6] R☉
Luminosity	790[5] L☉
Surface gravity (log g)	3.87[6] cgs
Temperature	15,490[6] K
Rotational velocity (v sin i)	205[3] km/s
Age	67.7[6] Myr
Other designations
γ Mus, CD−70°997, FK5 487, GC 17672, HD 109026, HIP 61199, HR 4773, SAO 257000
Database references
SIMBAD	data

This is a B-type main-sequence star with a stellar classification of B5 V.^[3] It is a variable star that ranges between magnitudes 3.84 and 3.86 over a period of 2.7 days, and is classed as a slowly pulsating B star.^[8] It is around five times as massive as the Sun.^[9] The star is spinning rapidly with a projected rotational velocity of 205 km/s. This is giving it an oblate shape with an equatorial bulge that is 7% larger than the polar radius.^[3]

Gamma Muscae is a proper motion member of the Lower Centaurus–Crux sub-group in the Scorpius–Centaurus OB association, the nearest such association of co-moving massive stars to the Sun.^[5]