27 Arietis is a binary star[4] system in the northern constellation of Aries. 27 Arietis is the Flamsteed designation. It is a dim, yellow-hued star that is close to the lower limit of what can be viewed with the naked eye, having an apparent visual magnitude is 6.21.[2] The annual parallax shift of 11.64±0.12 mas[1] corresponds to a physical distance of approximately 280 light-years (86 parsecs) from Earth. It is advancing closer to the Earth with a heliocentric radial velocity of −122.7 km/s, and may come as close as 84 light-years in around 643,000 years.[2]
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Aries |
Right ascension | 02h 30m 54.39715s[1] |
Declination | +17° 42′ 13.8908″[1] |
Apparent magnitude (V) | 6.21[2] |
Characteristics | |
Spectral type | G8 III-IV Fe-2[3] |
B−V color index | 0.908±0.002[2] |
Astrometry | |
Radial velocity (Rv) | −122.71±0.28[2] km/s |
Proper motion (μ) | RA: +33.774[1] mas/yr Dec.: −82.912[1] mas/yr |
Parallax (π) | 11.6403 ± 0.1172 mas[1] |
Distance | 280 ± 3 ly (85.9 ± 0.9 pc) |
Absolute magnitude (MV) | 1.48[2] |
Orbit[4] | |
Period (P) | 130.706±0.008 d |
Eccentricity (e) | 0.366±0.007 |
Periastron epoch (T) | 53,480.1±0.4 MJD |
Argument of periastron (ω) (secondary) | 275.5±0.7° |
Semi-amplitude (K1) (primary) | 5.98±0.05 km/s |
Details | |
Mass | 1.29[5] M☉ |
Radius | 7.04+0.29 −0.28 R☉ |
Luminosity | 28.43[2] L☉ |
Surface gravity (log g) | 2.77±0.21[6] cgs |
Temperature | 4,788±49[5] K |
Metallicity [Fe/H] | −0.65±0.02[2] dex |
Rotational velocity (v sin i) | 1.6[4] km/s |
Age | 5.44[5] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
This appears to be a single-lined spectroscopic binary system with an orbital period of 130.7 days and an eccentricity of 0.366. It has an "a sin i" value of 10.00 ± 0.08 Gm (0.06685 ± 0.00053 AU), where a is the semimajor axis and i is the inclination to the line of sight from the Earth. This value provides a lower bound on the actual semimajor axis.[4] The visible component has a stellar classification of G8 III-IV Fe-2,[3] displaying mixed spectral traits of an evolved subgiant and a giant star, with a strong underabundance of iron. The CN bands of this star are very weak.[4]