Mu Arietis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 02h 42m 21.936s |
| Declination | +20° 00′ 41.28″ |
| Apparent magnitude (V) | 5.74 (6.38/8.38/6.72/12.2) |
| Characteristics | |
| Spectral type | A0 Vp + F2 V + A1 V |
| U−B color index | −0.03 |
| B−V color index | −0.02 |
| Astrometry | |
| Radial velocity (Rv) | −6.0 km/s |
| Proper motion (μ) | RA: +29.086 mas/yr Dec.: −46.133 mas/yr |
| Parallax (π) | 7.5702±0.1425 mas |
| Distance | 431 ± 8 ly (132 ± 2 pc) |
| Absolute magnitude (MV) | +0.41 |
| Orbit | |
| Period (P) | 8.845±0.046 yr |
| Semi-major axis (a) | 0.0563±0.0008″ |
| Eccentricity (e) | 0.337±0.023 |
| Inclination (i) | 71.2±1.1° |
| Longitude of the node (Ω) | 101.0±1.0° |
| Periastron epoch (T) | B 1981.099±0.063 |
| Argument of periastron (ω) (secondary) | 92.3±1.7° |
| Details | |
| μ Ari Aa | |
| Mass | 3.4±1.7 M☉ |
| Luminosity | 71.7 L☉ |
| Rotational velocity (v sin i) | 175 km/s |
| μ Ari Ab | |
| Mass | 2.1±1.7 M☉ |
| Other designations | |
| μ Ari, 34 Arietis, BD+19 403, GC 3256, HD 16811, HIP 12640, HR 793, SAO 93062, PPM 91916, WDS J02424+2001 | |
| Database references | |
| SIMBAD | data |
Mu Arietis is a multiple star system in the northern constellation of Aries. Its name is a Bayer designation that is Latinized from μ Arietis, and abbreviated Mu Ari or μ Ari. This system is approximately 431 light-years (132 parsecs) distant from Earth, give or take a 8 light-year margin of error, and has a combined apparent visual magnitude of 5.74. According to the Bortle Dark-Sky Scale, this means it is faintly visible to the naked eye from dark suburban skies. The system is positioned near the ecliptic and is subject to lunar occultation.
At the heart of this system is a close orbiting pair, designated μ Ari Aa, consisting of a magnitude 6.38 A-type main sequence star with a stellar classification of A0 Vp, and a magnitude 8.38 F-type main sequence companion with a classification of F2 V. These two components have an angular separation of 0.04 arcseconds. A third component, designated μ Ari Ab, consists of a magnitude 6.72 star with a classification of A1 V, orbiting the inner pair with a period of 8.845 years and an eccentricity of 0.34. The orbit of this star has been measured using lunar occultations. A smaller fourth component, μ Ari B, at an angular separation of 19.1 arcseconds, has a magnitude of 12.2.