R Muscae
Variable star in the constellation Musca
From Wikipedia, the free encyclopedia
R Muscae is a yellow-white hued variable star in the southern constellation of Musca. It has a nominal apparent visual magnitude of 6.31,[5] which is near the lower limit of visibility to the naked eye. The distance to this star, as determined from its annual parallax shift of 1.00 mas,[2] is around 3,260 light years.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Musca |
| Right ascension | 12h 42m 05.02561s[2] |
| Declination | −69° 24′ 27.1966″[2] |
| Apparent magnitude (V) | 5.93 - 6.73[3] |
| Characteristics | |
| Spectral type | F7 Ib[4] - G2[3] |
| B−V color index | 0.750±0.020[5] |
| Variable type | δ Cep[3] |
| Astrometry | |
| Radial velocity (Rv) | +3.8±2.9[6] km/s |
| Proper motion (μ) | RA: −4.180[2] mas/yr Dec.: −2.127[2] mas/yr |
| Parallax (π) | 1.0002±0.0291 mas[2] |
| Distance | 3,260 ± 90 ly (1,000 ± 30 pc) |
| Absolute magnitude (MV) | -3.62[7] |
| Details | |
| Radius | 65[2] R☉ |
| Luminosity | 2,541[2] L☉ |
| Surface gravity (log g) | 2.0±0.1[8] cgs |
| Temperature | 5,985±54[7] K |
| Metallicity [Fe/H] | +0.10±0.05[8] dex |
| Other designations | |
| R Mus, AAVSO 1236-68, CD−68°1119, HD 110311, HIP 61981, HR 4820, SAO 251996[9] | |
| Database references | |
| SIMBAD | data |
This is an F-type supergiant star with a baseline stellar classification of F7 Ib.[4] It is a Classical Cepheid variable ranging from apparent magnitude 5.93 to 6.73[10] over 7.51 days,[7] while varying between spectral types F7 Ib and G2.[10] The star was suspected of having a detectable companion,[11] but this finding was later disputed.[12] Gaia and HST observations have shown that there is a companion, a 15th-magnitude star 7″ away.[13][14] There is an X-ray source with a luminosity of 6.3×1029 erg s−1 located at an angular separation of 1.9″ from R Muscae.[15]
