4 Andromedae
Star in the constellation Andromeda
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4 Andromedae, abbreviated 4 And, is a single[9] star in the northern constellation of Andromeda. 4 Andromedae is the Flamsteed designation. It is dimly visible to the naked eye with an apparent visual magnitude of 5.308.[3] Based upon an annual parallax shift of 9.16 mas[2] as seen from Earth's orbit, it is located 356 light years away. At this distance, interstellar extinction diminishes the apparent magnitude of 4 And by 0.5326 magnitudes.[2] The star is moving closer with a heliocentric radial velocity of −11 km/s.[10] It has a magnitude 11.7 visual companion at an angular separation of 51.10″ along a position angle of 348°, as of 2002.[11]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda[1] |
| Right ascension | 23h 07m 39.2672s[2] |
| Declination | +46° 23′ 14.030″[2] |
| Apparent magnitude (V) | 5.308[3] |
| Characteristics | |
| Evolutionary stage | red giant branch[2] |
| Spectral type | K5 III[4] |
| B−V color index | 1.436[3] |
| Astrometry | |
| Radial velocity (Rv) | −11.89±0.12[2] km/s |
| Proper motion (μ) | RA: −12.734 mas/yr[2] Dec.: −30.026 mas/yr[2] |
| Parallax (π) | 9.155±0.0779 mas[2] |
| Distance | 356 ± 3 ly (109.2 ± 0.9 pc) |
| Absolute magnitude (MV) | +0.16[1] |
| Details | |
| Mass | 1.58±0.44[5] M☉ |
| Radius | 23.36±0.59[6] R☉ |
| Luminosity | 170[7] L☉ |
| Surface gravity (log g) | 1.91[3] cgs |
| Temperature | 4,275±92[5] K |
| Metallicity [Fe/H] | 1.98±0.11[5] dex |
| Age | 2.24+0.78 −0.58[5] Gyr |
| Other designations | |
| 4 And, BD+45°4149, FK5 3852, HD 218452, HIP 114200, HR 8804, SAO 52711, PPM 63840, WDS J23077+4623A[8] | |
| Database references | |
| SIMBAD | data |
At the age of 2.2[5] billion years, this is an aging giant star with a stellar classification of K5 III,[4] having consumed the hydrogen at its core and evolved away from the main sequence. It has 1.6[5] times the mass of the Sun and has expanded to 23[6] times the Sun's radius. The star is radiating 170[7] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,275 K.[5]