HD 199223

HD 199223 (HR 8010) is a double star in the equatorial constellation Delphinus. However, the system was originally in Equuleus prior to the creation of official IAU constellation borders.^[15] The components have a separation of 2″ at a position angle of 282° as of 2016.^[16] They have apparent magnitudes of 6.34 and 7.49 and distances of 354 and 359 light years respectively. The system is drifting closer with a radial velocity of −33 km/s.

HD 199223

Location of HD 199223 (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Delphinus
A
Right ascension	20h 55m 40.6778s[1]
Declination	+04° 31′ 57.7994″[1]
Apparent magnitude (V)	6.34±0.01[2]
B
Right ascension	20h 55m 40.5439s[3]
Declination	+04° 31′ 58.2271″[3]
Apparent magnitude (V)	7.49±0.01[2]
Characteristics
A
Spectral type	G8 III/IV[4]
U−B color index	+0.49[5]
B−V color index	+0.82[5]
B
Spectral type	F/G[6]
Astrometry
Radial velocity (Rv)	−32.6±0.4[7] km/s
Absolute magnitude (MV)	+0.33[8]
A
Proper motion (μ)	RA: +60.413[1] mas/yr Dec.: +10.949[1] mas/yr
Parallax (π)	9.2067±0.0354 mas[1]
Distance	354 ± 1 ly (108.6 ± 0.4 pc)
B
Proper motion (μ)	RA: +60.315[3] mas/yr Dec.: +9.758[3] mas/yr
Parallax (π)	9.0757±0.0758 mas[3]
Distance	359 ± 3 ly (110.2 ± 0.9 pc)
Details
A
Mass	1.25[9] M☉
Radius	8.26+0.65 −0.22[10] R☉
Luminosity	37.1±0.4[10] L☉
Surface gravity (log g)	2.60±0.25[11] cgs
Temperature	4,956+68 −185[10] K
Metallicity [Fe/H]	0.13±0.09[11] dex
Rotational velocity (v sin i)	<1[12] km/s
B
Mass	1.46[9] M☉
Radius	2.10+0.16 −0.27[13] R☉
Luminosity	8.82±0.23[13] L☉
Surface gravity (log g)	3.85[9] cgs
Temperature	6,865+494 −251[13] K
Metallicity [Fe/H]	−0.2[9] dex
Other designations
1 G. Equulei, AG+04°2834, BD+03°4461, GC 29200, HD 199223, HIP 103301, HR 8010, SAO 126373, WDS J20557+0432[14]
Database references
SIMBAD	The system
	A
	B

The brighter component has a stellar classification of G8 III/IV,^[4] indicating that it is a G-type star with the blended luminosity class of a giant star and a subgiant. It has 125% of the mass of the Sun^[9] and an enlarged radius of 8.26 R_☉.^[10] It shines at 37.1 times the luminosity of the Sun^[10] from its photosphere at an effective temperature of 4,956 K,^[10] giving it a yellow glow. HD 199223A's iron abundance is 135% that of the Sun^[11] and it spins modestly with a projected rotational velocity less than 1 km/s.^[12]

As for the dimmer one, it is classified as an F/G star,^[6] and is calculated to be an F-type subgiant. It has 146% of the mass of the Sun^[9] and 2.1 times its radius.^[13] It radiates with a luminosity of 8.82 L_☉^[13] from its photosphere at an effective temperature of 6,865 K,^[13] giving it a yellow white glow.