49 Andromedae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 01h 30m 06.10151s |
| Declination | +47° 00′ 26.1811″ |
| Apparent magnitude (V) | 5.269 |
| Characteristics | |
| Evolutionary stage | red clump |
| Spectral type | K0 III |
| B−V color index | 0.993 |
| Astrometry | |
| Radial velocity (Rv) | −11.48 km/s |
| Proper motion (μ) | RA: −0.950 mas/yr Dec.: −42.638 mas/yr |
| Parallax (π) | 9.7947±0.1166 mas |
| Distance | 333 ± 4 ly (102 ± 1 pc) |
| Absolute magnitude (MV) | 0.50 |
| Details | |
| Mass | 2.07 M☉ |
| Radius | 11 R☉ |
| Luminosity | 70.8 L☉ |
| Surface gravity (log g) | 2.30 cgs |
| Temperature | 4,879±106 K |
| Metallicity [Fe/H] | +0.020±0.04 dex |
| Rotational velocity (v sin i) | 2.0 km/s |
| Age | 1.75 Gyr |
| Other designations | |
| A And, 49 And, BD+46°370, HD 9057, HIP 6999, HR 430, SAO 37275, PPM 44057, GSC 03282-02272 | |
| Database references | |
| SIMBAD | data |
49 Andromedae is a star in the constellation Andromeda. 49 Andromedae is the Flamsteed designation (abbreviated 49 And), though it also bears the Bayer designation A Andromedae. It is visible to the naked eye under good viewing conditions with an apparent visual magnitude of 5.269. The distance to 49 Andromedae, as determined from its annual parallax shift of 9.8 mas, is around 333 light-years. It is drifting closer to the Sun with a heliocentric radial velocity of −11.5 km/s.
With an estimated age of 1.75 Gyr years, this is an aging red-clump giant star with a stellar classification of K0 III, indicating it is generating energy by helium fusion at its core. The spectrum displays "slightly strong" absorption lines of cyanogen (CN). It has 2.07 times the mass of the Sun and has expanded to 11 times the Sun's radius. The star is radiating 71 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,879 K. It is spinning with a projected rotational velocity of 2 km/s.
This was one of the stars historically known as Adhil, from Arabic að-ðayl "the train [of a garment]", a name now applied to ξ Andromedae. In a 1971 NASA technical memorandum listing star names, 49 Andromedae was listed as Thail, likely derived from the same Arabic name.