Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aries |
Right ascension | 03h 09m 36.74277s[1] |
Declination | +29° 04′ 37.4872″[1] |
Apparent magnitude (V) | 5.72[2] |
Characteristics | |
Spectral type | B8 III[3] |
U−B color index | –0.15[2] |
B−V color index | +0.115±0.005[4] |
Astrometry | |
Radial velocity (Rv) | −2.0±4.3[4] km/s |
Proper motion (μ) | RA: +19.192[1] mas/yr Dec.: −12.057[1] mas/yr |
Parallax (π) | 3.5853 ± 0.1194 mas[1] |
Distance | 910 ± 30 ly (279 ± 9 pc) |
Absolute magnitude (MV) | −1.75[4] |
Details | |
Mass | 4.1[5] M☉ |
Radius | 9.49+0.32 −0.56[1] R☉ |
Luminosity | 326±13[1] L☉ |
Surface gravity (log g) | 2.948±0.023[5] cgs |
Temperature | 7,961+246 −128[1] K |
Rotational velocity (v sin i) | 196±10[5] km/s |
Other designations | |
Database references | |
SIMBAD | data |
55 Arietis is a single[7] star in the northern zodiac constellation of Aries. 55 Arietis is the Flamsteed designation. It is faintly visible to the naked eye as a dim, blue-white hued point of light with an apparent visual magnitude of 5.72.[2] Based upon an annual parallax shift of 3.6 mas,[1] it is approximately 910 light-years (280 parsecs) distant from Earth, give or take a 30 light-year margin of error. Eggen (1995) listed it as a proper motion candidate for membership in the IC 2391 supercluster.[8] It may be a runaway star, having a peculiar velocity of 25.9+3.9
−6.1 km/s relative to its neighbors.[9]
The spectrum of this star matches a B-type giant with a stellar classification of B8 III.[3] It has a high rate of spin, showing a projected rotational velocity of 196 km/s.[5] The star has 4.1[5] times the mass of the Sun but 9.5[1] times the Sun's radius. It is radiating 326[1] times as much luminosity as the Sun from its photosphere at an effective temperature of 7,961 K.[1]