Epsilon Muscae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Musca |
| Right ascension | 12h 17m 34.27564s |
| Declination | −67° 57′ 38.6525″ |
| Apparent magnitude (V) | 4.0 – 4.3 |
| Characteristics | |
| Evolutionary stage | asymptotic giant branch |
| Spectral type | M5 III |
| Variable type | SRb |
| Astrometry | |
| Radial velocity (Rv) | 7.1±0.7 km/s |
| Proper motion (μ) | RA: −230.607±0.187 mas/yr Dec.: −26.206±0.263 mas/yr |
| Parallax (π) | 9.9915±0.2 mas |
| Distance | 326 ± 7 ly (100 ± 2 pc) |
| Absolute magnitude (MV) | −0.77 |
| Details | |
| Mass | 2±0.3 M☉ |
| Radius | 116±9 R☉ |
| Luminosity | 1,738 L☉ |
| Surface gravity (log g) | 0.6±0.02 cgs |
| Temperature | 3,470±125 K |
| Other designations | |
| eps Mus, CPD−67 1931, HD 106849, HIP 59929, HR 4671, SAO 251830 | |
| Database references | |
| SIMBAD | data |
Epsilon Muscae, Latinized as ε Muscae, is a red giant star of spectral type M5III in the constellation Musca. It is a 4th magnitude star, visible to the naked eye under good observing conditions. It is about 330 light-years from the Earth.
Originally a main-sequence star of around 2 solar masses, Epsilon Muscae is now on the asymptotic giant branch and has expanded to 117 times the Sun's diameter and 1,700 its luminosity. It is a semiregular variable, varying between visual magnitudes 4.0 and 4.3 in eight distinct periods ranging from a month to over half a year in length. Its distance from the Earth is about the same 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.