39 Andromedae
39 Andromedae, abbreviated 39 And, is a double star in the northern constellation Andromeda. 39 Andromedae is the Flamsteed designation. Its apparent visual magnitude is 5.95, which indicates it is near the lower limit on visibility to the naked eye. The distance to this star, as estimated from its annual parallax shift of 9.57 mas, is 341 light years. It is a suspected member of the Ursa Major Moving Group, although King et al. (2003) list it as a probable non-member.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 01h 02m 54.25356s |
| Declination | +41° 20′ 42.7673″ |
| Apparent magnitude (V) | 5.95 |
| Characteristics | |
| Spectral type | kA3hA7VmA9 |
| B−V color index | +0.161±0.009 |
| Astrometry | |
| Radial velocity (Rv) | +3.1±0.9 km/s |
| Proper motion (μ) | RA: −17.558 mas/yr Dec.: −18.400 mas/yr |
| Parallax (π) | 9.5725 ± 0.0805 mas |
| Distance | 341 ± 3 ly (104.5 ± 0.9 pc) |
| Absolute magnitude (MV) | 0.80 |
| Details | |
| Radius | 1.2 R☉ |
| Luminosity | 39.95 L☉ |
| Surface gravity (log g) | 3.93 cgs |
| Temperature | 8,073 K |
| Metallicity [Fe/H] | +0.13 dex |
| Rotational velocity (v sin i) | 34 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
The brighter component is a confirmed Am star with a stellar classification of kA3hA7VmA9. This notation indicates its spectrum displays the calcium K line of an A3 star, the hydrogen lines of an A7 V, or A-type main-sequence star, and the metal lines of an A9 star. It is radiating 40 times the Sun's luminosity from its photosphere at an effective temperature of 8,073 K. As of 2015, the magnitude 12.48 companion star is located at an angular separation of 20.5″ along a position angle of 3° from the primary.