HD 28204
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  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Camelopardalis[1] |
| Right ascension | 04h 33m 30.68009s[2] |
| Declination | +72° 31′ 42.9803″[2] |
| Apparent magnitude (V) | 5.93±0.01[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | kA8 hF0 mF2[4] |
| U−B color index | +0.16[5] |
| B−V color index | +0.28[5] |
| Astrometry | |
| Radial velocity (Rv) | 9.0±0.9[6] km/s |
| Proper motion (μ) | RA: +30.055 mas/yr[2] Dec.: −90.625 mas/yr[2] |
| Parallax (π) | 9.8596±0.0214 mas[2] |
| Distance | 330.8 ± 0.7 ly (101.4 ± 0.2 pc) |
| Absolute magnitude (MV) | +0.91[1] |
| Orbit[7] | |
| Period (P) | 4.1950 d |
| Eccentricity (e) | 0.040±0.029[8] |
| Inclination (i) | 28-43° |
| Periastron epoch (T) | 2,426,034.6450 JD |
| Argument of periastron (ω) (secondary) | 337±244[8]° |
| Semi-amplitude (K1) (primary) | 31.3 km/s |
| Details | |
| Aa | |
| Mass | 1.68[9] M☉ |
| Radius | 3.48±0.18[10] R☉ |
| Luminosity | 35.7±0.2[2] L☉ |
| Surface gravity (log g) | 3.58+0.10 −0.06[11] cgs |
| Temperature | 7,320±157[12] K |
| Metallicity [Fe/H] | −0.14[13] dex |
| Rotational velocity (v sin i) | 23±10[4] km/s |
| Age | 1.103[14] Gyr |
| Ab | |
| Mass | 0.474[9] M☉ |
| Other designations | |
| AG+72°116, BD+72°227A, FK5 2333, GC 5478, HD 28204, HIP 21247, HR 1401, SAO 5238, ADS 3267 A, CCDM J04335+7232A, WDS J04335+7232A, TIC 103566595[15] | |
| Database references | |
| SIMBAD | data |
HD 28204, also designated as HR 1401, is a spectroscopic binary[16] located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.93,[3] making it faintly visible to the naked eye under ideal conditions. Gaia DR3 parallax measurements imply a distance of 331 light-years and it is currently receding with a heliocentric radial velocity of 9 km/s.[6] At its current distance, HD 28204's brightness is diminished by 0.18 magnitudes due to interstellar extinction and it has an absolute magnitude of +0.91.[1]
HD 28204 is a single-lined spectroscopic binary consisting of an Am star and an unseen companion, as the primary is the only one detectable in the spectrum. With a mass of 0.474 M☉,[9] the companion might be a K-type main-sequence star. Both stars take 4.2 days to revolve around each other in a nearly circular orbit, which is somewhat constrained.[7] HD 28204 has two optical companions: a 12th magnitude star located 39" away along a position angle of 257° and a 14th magnitude star located 27.3" along a position angle of 55°.[17]
The visible component has a stellar classification of kA8hF0mF2,[4] indicating that it is an Am star with the calcium K-lines of an A8 star, the hydrogen lines of a F0 star, and the metallic lines of a F2 star. It has 1.68 times the mass of the Sun[9] and an enlarged radius 3.48 times that of the Sun.[10] It radiates 35.7 times the luminosity of the Sun[2] from its photosphere at an effective temperature of 7,320 K,[12] giving it the typical white hue of an A-type star. It is slightly metal deficient with an iron abundance of [Fe/H] = −0.15 or 72% that of the Sun's.[13] Like many Am stars it spins slowly, having a projected rotational velocity of 23 km/s.[4]
