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Double star in the constellation Delphinus. From Wikipedia, the free encyclopedia
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.
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 | |
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.