HD 200044

HD 200044 (HR 8044) is a solitary^[13] star in the equatorial constellation Delphinus. It has an apparent magnitude of 5.7,^[2] allowing it to be faintly seen with the naked eye. The object is located 598 light years away,^[1] but is approaching the Solar System with a heliocentric radial velocity of −15.07 km/s.^[7]

HD 200044

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Delphinus
Right ascension	21h 00m 27.6883s[1]
Declination	+19° 19′ 46.493″[1]
Apparent magnitude (V)	5.70±0.01[2]
Characteristics
Evolutionary stage	AGB[3]
Spectral type	M3 IIIab[4]
B−V color index	+1.61[5]
Variable type	suspected[6]
Astrometry
Radial velocity (Rv)	−15.07±0.09[7] km/s
Proper motion (μ)	RA: −15.483 mas/yr[1] Dec.: −59.705 mas/yr[1]
Parallax (π)	5.455±0.0753 mas[1]
Distance	598 ± 8 ly (183 ± 3 pc)
Absolute magnitude (MV)	−0.33[8]
Details
Mass	1.32[9] M☉
Radius	58[10] R☉
Luminosity	507[11] L☉
Surface gravity (log g)	0.93[12] cgs
Temperature	3,707[10] K
Other designations
AG+19°2128, BD+18°4675, GC 29329, HD 200044, HIP 103675, HR 8044, SAO 106747, WDS J21005+1920A
Database references
SIMBAD	data

HD 200044 has a spectral classification of M3 IIIab,^[4] indicating that its an ageing red giant. It is currently on the asymptotic giant branch and is fusing hydrogen and helium in shells around an inert carbon core.^[3] As a consequence, it has expanded to 58 times the radius of the Sun and is now radiating with a luminosity over 500 times greater than that of the Sun. HD 200044's large size and high luminosity yield an effective temperature of 3,707 K, giving it a red glow. HD 200044 is suspected to be a variable star with an amplitude of 0.05 magnitudes.^[6]

There is a 10th magnitude optical companion separated 49.3″ away and at a position angle of 337° as of 2014. However, the separation is increasing due to HD 200044's high proper motion.^[14]