| 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 | |
| 27 Ari, BD+17°380, FK5 1069, HD 15596, HIP 11698, HR 731, SAO 92983 [7] | |
| Database references | |
| SIMBAD | data |
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]
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]