Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Octans |
Right ascension | 20h 24m 54.91771s[1] |
Declination | −83° 18′ 38.2301″[1] |
Apparent magnitude (V) | 6.14±0.01[2] |
Characteristics | |
Spectral type | A2/3 mA8-F0[3] |
U−B color index | +0.13[4] |
B−V color index | +0.20[4] |
Astrometry | |
Radial velocity (Rv) | 0.1±1.3[5] km/s |
Proper motion (μ) | RA: +23.223 mas/yr[1] Dec.: +6.228 mas/yr[1] |
Parallax (π) | 13.331 ± 0.0247 mas[1] |
Distance | 244.7 ± 0.5 ly (75.0 ± 0.1 pc) |
Absolute magnitude (MV) | +1.76[6] |
Details | |
Mass | 2.06±0.40[7] M☉ |
Radius | 2.17±0.06[8] R☉ |
Luminosity | 15.57[9] L☉ |
Surface gravity (log g) | 4.12±0.06[10] cgs |
Temperature | 7,706±126[11] K |
Metallicity [Fe/H] | −0.02[12] dex |
Age | 979±166[1] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 191220, also known as HR 7698, is a solitary white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 6.14,[2] placing it near the limit for naked eye visibility. The object is located relatively close at a distance of 245 light years based on Gaia DR3 parallax measurements[1] but is slowly receding with a heliocentric radial velocity of 0.1 km/s.[5] At its current distance, HD 191220's brightness is diminished by 0.22 magnitudes due to interstellar dust.[15]
This is a chemically peculiar Am star[16] with a stellar classification of A2/3mA8-F0,[3] an A-type star with the metallic lines of a star with a class of A8-F0. It has double the mass of the Sun and 2.2 times its girth.[7] It radiates 15.57 times the luminosity of the Sun[9] from its photosphere at an effective temperature of 7,706 K.[11] HD 191220 is estimated to be nearly a billion years old[12] and has a near solar metallicity — what astronomers dub a star's abundance of chemical elements heavier than helium.[12]