1 Cancri
1 Cancri is a single star in the zodiac constellation of Cancer, positioned near the border with Gemini at a distance of around 467 light years from the Sun. It is barely visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.97. The object is moving further from the Earth with a heliocentric radial velocity of +14 km/s.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 07h 56m 59.45262s |
| Declination | +15° 47′ 25.0019″ |
| Apparent magnitude (V) | 5.97 |
| Characteristics | |
| Spectral type | K3− III |
| B−V color index | 1.285±0.007 |
| Astrometry | |
| Radial velocity (Rv) | +13.55±0.12 km/s |
| Proper motion (μ) | RA: −26.731 mas/yr Dec.: −42.7591 mas/yr |
| Parallax (π) | 6.9810 ± 0.0694 mas |
| Distance | 467 ± 5 ly (143 ± 1 pc) |
| Absolute magnitude (MV) | 0.03 |
| Details | |
| Mass | 1.1 M☉ |
| Radius | 18.7 R☉ |
| Luminosity | 199 L☉ |
| Surface gravity (log g) | 2.03 cgs |
| Temperature | 4,231 K |
| Metallicity [Fe/H] | −0.01 dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an evolved giant star with a stellar classification of K3− III, having exhausted the hydrogen at its core and expanded. It is specified as a spectral standard for that type. The angular diameter of the star measured from a lunar occultation is 2.1±0.6 mas, which, at its estimated distance, equates to a physical radius of about 19 times the radius of the Sun. It is radiating 199 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,231 K.