Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Camelopardalis |
Right ascension | 03h 33m 39.06000s[1] |
Declination | +54° 58′ 29.4970″[1] |
Apparent magnitude (V) | 5.97±0.01[2] |
Characteristics | |
Evolutionary stage | main sequence star[3] |
Spectral type | A3 V[4] or A2 Vp[5] |
B−V color index | +0.11[6] |
Astrometry | |
Radial velocity (Rv) | −6.5±1.5[7] km/s |
Proper motion (μ) | RA: −41.053 mas/yr[1] Dec.: −0.357 mas/yr[1] |
Parallax (π) | 13.1723 ± 0.0317 mas[1] |
Distance | 247.6 ± 0.6 ly (75.9 ± 0.2 pc) |
Absolute magnitude (MV) | +1.62[8] |
Details | |
Mass | 2.00+0.19 −0.15[9] M☉ |
Radius | 2.06±0.10[10] R☉ |
Luminosity | 30.6+2.2 −2.0[3] L☉ |
Surface gravity (log g) | 4.08[11] cgs |
Temperature | 9,000[12] K |
Metallicity [Fe/H] | −0.17[11] dex |
Rotational velocity (v sin i) | 160±8[5] km/s |
Age | 737±102[9] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 21819, also designated as HR 1073, is a solitary star[14] located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.97,[2] making faintly visible to the naked eye under ideal conditions. The object is located relatively close at a distance of 248 light-years based on Gaia DR3 parallax measurements[1] and it is drifting closer with a heliocentric radial velocity of −6.5 km/s.[7] At its current distance, HD 21819's brightness is diminished by an interstellar extinction of 0.17 magnitudes[15] and it has an absolute magnitude of +1.62.[8]
HD 21819 has a stellar classification of A3 V,[4] indicating that it is an ordinary A-type main-sequence star that is generating energy via hydrogen fusion at its core. Abt & Morell (1995) gave a slightly hotter star of A2 Vp,[5] indicating that it is instead an Ap star with weak magnesium lines. It has twice the mass of the Sun[9] and 2.06 times the radius of the Sun.[10] It radiates 30.6 times the luminosity of the Sun[3] from its photosphere at an effective temperature of 9,000 K,[12] giving it a white hue when viewed in the night sky. HD 21819 is metal deficient with an iron abundance of [Fe/H] = −0.17 or 67.6% of the Sun's[11] and it is estimated to be 737 million years old,[9] having completed 55.7% of its main sequence lifetime.[3] Like most hot stars it spins rapidly, having a projected rotational velocity of 160 km/s.[5]