Epsilon Muscae

Epsilon Muscae, Latinized as ε Muscae, is a red giant star of spectral type M5III in the constellation Musca.[5] Originally a main-sequence star of around 1.5 to 2 solar masses, it is now on the asymptotic giant branch[4] and has now expanded to 130 times the Sun's diameter and 1800 to 2300 its luminosity.[7] It is a semiregular variable, varying between visual magnitudes 4.0 and 4.3[3] in eight distinct periods ranging from a month to over half a year in length.[5] It is located around 300 light-years distant,[2] the same distance as the Lower Centaurus–Crux subgroup of the Scorpius–Centaurus association, although it is moving much faster at around 100 km/s and does not share a common origin.[7]

Epsilon Muscae

A light curve for Epsilon Muscae, plotted from Hipparcos data[1]
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Musca
Right ascension	12h 17m 34.27716s[2]
Declination	−67° 57′ 38.6486″[2]
Apparent magnitude (V)	4.0 - 4.3[3]
Characteristics
Evolutionary stage	asymptotic giant branch[4]
Spectral type	M5 III[5]
Variable type	SRb[3]
Astrometry
Radial velocity (Rv)	7.1±0.7 km/s
Proper motion (μ)	RA: −231.04±0.13[2] mas/yr Dec.: −26.39±0.13[2] mas/yr
Parallax (π)	10.82 ± 0.17 mas[2]
Distance	301 ± 5 ly (92 ± 1 pc)
Absolute magnitude (MV)	−0.77[6]
Details
Mass	<1.5-2[7] M☉
Radius	~130[7] R☉
Luminosity	1800-2300[7] L☉
Temperature	3400[7] K
Other designations
eps Mus, CPD-67 1931, HD 106849, HIP 59929, HR 4671, SAO 251830.
Database references
SIMBAD	data