HD 22764
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  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Camelopardalis[1] |
| Right ascension | 03h 42m 42.73699s[2] |
| Declination | +59° 58′ 09.8029″[2] |
| Apparent magnitude (V) | 5.78[3] |
| Characteristics | |
| Spectral type | K3.5 IIIb + G[4] |
| U−B color index | +1.78[3] |
| B−V color index | +1.76[3] |
| R−I color index | +1.02[3] |
| Astrometry | |
| Radial velocity (Rv) | −12.53±0.26[5] km/s |
| Proper motion (μ) | RA: −2.124 mas/yr[2] Dec.: +2.342 mas/yr[2] |
| Parallax (π) | 1.8433±0.0671 mas[2] |
| Distance | 1,770 ± 60 ly (540 ± 20 pc) |
| Absolute magnitude (MV) | −4.47[6] |
| Absolute bolometric magnitude (Mbol) | −4.52±0.30[7] |
| Details | |
| Mass | 2.86[8] or 6.8±1[9] M☉ |
| Radius | 167±8[10] R☉ |
| Luminosity | 3,342±221[11] L☉ |
| Surface gravity (log g) | 1.08 or 1.41[12] cgs |
| Temperature | 3,928±170[7] K |
| Metallicity [Fe/H] | −0.19[13] dex |
| Rotational velocity (v sin i) | <1.9[14] km/s |
| Age | 820[8] or 47±8[9] Myr |
| Other designations | |
| AG+59°378, BD+59°699, HD 22764, HIP 17342, HR 1112, SAO 24169, WDS J03427+5958A[15] | |
| Database references | |
| SIMBAD | data |
HD 22764, also known as HR 1112, is an orange hued star located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.78,[3] allowing it to be faintly visible to the naked eye. The object is located relatively far at a distance of approximately 1,770 light years based on Gaia DR3 parallax measurements[2] but is approaching the Solar System with a heliocentric radial velocity of −12.5 km/s.[5] At its current distance, HD 22764's brightness is diminished by 0.66 magnitudes due to interstellar dust.[6]
The object has two stellar classifications; one states that it is an ageing red giant (K3.5 IIIb)[4] while the other instead lists it as a slightly cooler lower luminosity red supergiant (K4 Ib).[16] The first spectrum hints a close companion to the object of spectral type G. If considered as a supergiant, it has 6.8 times the mass of the Sun;[9] if considered as an older giant star, it has a mass of 2.86 M☉.[8] As a result of its evolved state, HD 22764 has expanded to 167 times the Sun's radius[10] and now radiates 3,342 times the luminosity of the Sun[11] from its photosphere at an effective temperature of 3,928 K.[7] Age estimates range from 47 up to 820 million years.[8][9] It has an iron abundance 65% that of the Sun,[13] making it metal deficient. The object spins leisurely with a projected rotational velocity lower than 1.9 km/s.[14]
HD 22764 is the primary of a binary star[17] consisting of it and HD 22763, a B8 giant star located 54.8" away along a position angle of 38°. There are also 4 line-of-sight companions located near the system.[18]
