39 Arietis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 02h 47m 54.54142s |
| Declination | +29° 14′ 49.6132″ |
| Apparent magnitude (V) | 4.514 |
| Characteristics | |
| Evolutionary stage | red clump |
| Spectral type | K1.5 III |
| U−B color index | +1.083 |
| B−V color index | +1.118 |
| R−I color index | 0.58 |
| Astrometry | |
| Radial velocity (Rv) | −15.53±0.14 km/s |
| Proper motion (μ) | RA: +149.47±0.25 mas/yr Dec.: −127.05±0.18 mas/yr |
| Parallax (π) | 19.01±0.21 mas |
| Distance | 172 ± 2 ly (52.6 ± 0.6 pc) |
| Details | |
| Mass | 1.6 M☉ |
| Radius | 10.22±0.72 R☉ |
| Luminosity | 48.7±0.7 L☉ |
| Surface gravity (log g) | 2.7 cgs |
| Temperature | 4,768±167 K |
| Metallicity [Fe/H] | −0.02 dex |
| Rotational velocity (v sin i) | 4.5 km/s |
| Other designations | |
| Lilii Borea, BD+28°462, HD 17361, HIP 13061, HR 824, SAO 75578. | |
| Database references | |
| SIMBAD | data |
39 Arietis (abbreviated 39 Ari), officially named Lilii Borea /ˈlɪliaɪ ˈbɔːriə/, is a star in the northern constellation of Aries. It is visible to the naked eye with an apparent visual magnitude of +4.5. The distance to this star, as determined from an annual parallax shift of 19.01 mas, is approximately 172 light-years (53 parsecs). This star was formerly located in the obsolete constellation Musca Borealis.