4 Andromedae

Location of 4 Andromedae (circled)
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

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]

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]

References

External links

• Image 4 Andromedae