66 Arietis (abbreviated 66 Ari) is a double star[3] in the northern constellation of Aries. 66 Arietis is the Flamsteed designation. It has an apparent visual magnitude of 6.03,[2] putting it near the limit for naked eye visibility. The magnitude 10.4 companion is located at an angular separation of 0.810 arcseconds from the primary along a position angle of 65°.[3] The distance to this pair, as determined from parallax measurements made during the Hipparcos mission, is approximately 210 light-years (64 parsecs).[1]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 03h 28m 26.56850s[1] |
| Declination | +22° 48′ 14.4271″[1] |
| Apparent magnitude (V) | 6.03[2] (6.2/10.4)[3] |
| Characteristics | |
| Spectral type | K0 IV[4] |
| B−V color index | 0.964[5] |
| Astrometry | |
| Radial velocity (Rv) | +48.99 ± 0.16[5] km/s |
| Proper motion (μ) | RA: +2.12[1] mas/yr Dec.: –110.85[1] mas/yr |
| Parallax (π) | 15.52 ± 0.81 mas[1] |
| Distance | 210 ± 10 ly (64 ± 3 pc) |
| Details | |
| 66 Ari A | |
| Radius | 6[5] R☉ |
| Luminosity | 18[5] L☉ |
| Surface gravity (log g) | 3.0[5] cgs |
| Temperature | 4,864[5] K |
| Rotational velocity (v sin i) | 1.6[5] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
The spectrum of the primary component matches a stellar classification of K0 IV,[4] with the luminosity class of IV indicating this is a subgiant star. It has 6 times the radius of the Sun and shines with 18 times the Sun's energy.[5] This energy is radiated from the outer atmosphere at an effective temperature of 4,864 K,[5] giving it the cool orange-hued glow of a K-type star.