HD 4628
HD 4628 (96 G. Piscium) is a main sequence star in the equatorial constellation of Pisces. It has a spectral classification of K2.5 V and an effective temperature of 5,055 K, giving it an orange-red hue with a slightly smaller mass and girth than the Sun. HD 4628 lies at a distance of approximately 24.3 light years from the Sun based on parallax. The apparent magnitude of 5.7 is just sufficient for this star to be viewed with the unaided eye. The star appears to be slightly older than the Sun—approximately 5.4 billion years in age. The surface activity is low and, based upon the detection of UV emission, it may have a relatively cool corona with a temperature of one million K.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pisces |
| Right ascension | 00h 48m 22.97634s |
| Declination | +05° 16′ 50.2096″ |
| Apparent magnitude (V) | 5.74 |
| Characteristics | |
| Spectral type | K2.5 V |
| U−B color index | +0.60 |
| B−V color index | +0.89 |
| Astrometry | |
| Radial velocity (Rv) | −10.41±0.15 km/s |
| Proper motion (μ) | RA: 755.561 mas/yr Dec.: −1,141.745 mas/yr |
| Parallax (π) | 134.4948 ± 0.0578 mas |
| Distance | 24.25 ± 0.01 ly (7.435 ± 0.003 pc) |
| Absolute magnitude (MV) | 6.37 |
| Details | |
| Mass | 0.70±0.10 M☉ |
| Radius | 0.749±0.051 R☉ |
| Luminosity | 0.28 L☉ |
| Surface gravity (log g) | 4.39±0.16 cgs |
| Temperature | 5,055±40 K |
| Metallicity [Fe/H] | –0.22 dex |
| Rotation | 38.0 days |
| Age | 5.4 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The star has a relatively high proper motion of 1.4″ per year and is moving in our general direction with a radial velocity of −10.4 km/s. HD 4628 will make its closest approach to the Sun in about 32,000 years, when it comes within 20 ly (7.3 pc). No definitive companion has yet been found in orbit around this star. In 1958 it was thought to have stellar companion that was also a flare star, but this was subsequently disproved.