49 Andromedae
Star in the constellation Andromeda
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49 Andromedae is a star in the constellation Andromeda.[1] 49 Andromedae is the Flamsteed designation (abbreviated 49 And),[9] though it also bears the Bayer designation a Andromedae.[8] It is visible to the naked eye under good viewing conditions with an apparent visual magnitude of 5.269.[3] The distance to 49 Andromedae, as determined from its annual parallax shift of 9.8 mas,[2] is around 333 light-years. It is drifting closer to the Sun with a heliocentric radial velocity of −11.5 km/s.[3]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda[1] |
| Right ascension | 01h 30m 06.10151s[2] |
| Declination | +47° 00′ 26.1811″[2] |
| Apparent magnitude (V) | 5.269[3] |
| Characteristics | |
| Evolutionary stage | red clump[4] |
| Spectral type | K0 III[5] |
| B−V color index | 0.993[3] |
| Astrometry | |
| Radial velocity (Rv) | −11.48[3] km/s |
| Proper motion (μ) | RA: −0.950 mas/yr[2] Dec.: −42.638 mas/yr[2] |
| Parallax (π) | 9.7947±0.1166 mas[2] |
| Distance | 333 ± 4 ly (102 ± 1 pc) |
| Absolute magnitude (MV) | 0.50[1] |
| Details | |
| Mass | 2.07[3] M☉ |
| Radius | 11[6] R☉ |
| Luminosity | 70.8[3] L☉ |
| Surface gravity (log g) | 2.30[4] cgs |
| Temperature | 4,879±106[3] K |
| Metallicity [Fe/H] | +0.020±0.04[4] dex |
| Rotational velocity (v sin i) | 2.0[7] km/s |
| Age | 1.75[3] Gyr |
| Other designations | |
| a And[8], 49 And, BD+46°370, HD 9057, HIP 6999, HR 430, SAO 37275, PPM 44057, GSC 03282-02272[9] | |
| Database references | |
| SIMBAD | data |
With an estimated age of 1.75 Gyr[3] years, this is an aging red-clump[4] giant star with a stellar classification of K0 III,[5] indicating it is generating energy by helium fusion at its core. The spectrum displays "slightly strong" absorption lines of cyanogen (CN).[5] It has 2.07[3] times the mass of the Sun and has expanded to 11[6] times the Sun's radius. The star is radiating 71[3] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,879 K.[3] It is spinning with a projected rotational velocity of 2 km/s.[7]
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.[10] In a 1971 NASA technical memorandum listing star names, 49 Andromedae was listed as Thail, likely derived from the same Arabic name.[11]