Delta Muscae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Musca |
| Right ascension | 13h 02m 16.26474s |
| Declination | −71° 32′ 55.8752″ |
| Apparent magnitude (V) | +3.61 |
| Characteristics | |
| Spectral type | K2III |
| U−B color index | +1.26 |
| B−V color index | +1.18 |
| Astrometry | |
| Radial velocity (Rv) | 36.5±0.9 km/s |
| Proper motion (μ) | RA: 264.17 mas/yr Dec.: −22.75 mas/yr |
| Parallax (π) | 35.88±0.44 mas |
| Distance | 91 ± 1 ly (27.9 ± 0.3 pc) |
| Absolute magnitude (MV) | +1.38 |
| Orbit | |
| Period (P) | 423.2±0.10 d |
| Semi-major axis (a) | 12.1±0.35 mas |
| Eccentricity (e) | 0.52±0.06 |
| Inclination (i) | 120±2.3° |
| Longitude of the node (Ω) | 58±2.7° |
| Periastron epoch (T) | 25,945±5.5 JD |
| Argument of periastron (ω) (secondary) | 319±4.2° |
| Semi-amplitude (K1) (primary) | 8.8±0.38 km/s |
| Details | |
| A | |
| Mass | 1.5 M☉ |
| Radius | 8.6 R☉ |
| Luminosity | 31 L☉ |
| Surface gravity (log g) | 2.5 cgs |
| Temperature | 4,500 K |
| B | |
| Mass | 0.4 M☉ |
| Other designations | |
| δ Mus, CD−70°997, FK5 487, GC 17672, HD 112985, HIP 63613, HR 4923, SAO 257000 | |
| Database references | |
| SIMBAD | data |
Delta Muscae, Latinized from δ Muscae, often catalogued as HD 112985, is a spectroscopic binary star system and the closest to the Earth in the southern hemisphere constellation of Musca (the Fly) at a distance of approximately 27.8 parsecs (91.0 light years). The main star is classified as a giant star with an orange tint. It is one of the stars given a Bayer designation by astronomer Johann Bayer. It was recorded in Bayer's 1603 publication Uranometria. In addition it is one of the main stars used in the visual formation of the Musca constellation.