Upsilon1 Cancri
Star in the constellation Cancer
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Upsilon1 Cancri is a solitary,[4] yellow-white-hued star in the constellation Cancer. Its name is a Bayer designation that is Latinized from υ1 Cancri, and abbreviated Upsilon1 Cnc or υ1 Cnc. This star is faintly visible to the naked eye, having an apparent visual magnitude of +5.7.[3] Based upon an annual parallax shift of 13.62 mas as seen from Earth,[2] this system is 240 light-years (73 pc) distant from the Sun. It is drifting further away with a line of sight velocity of +19 km/s.[5]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer[1] |
| Right ascension | 08h 31m 30.519s[2] |
| Declination | +24° 04′ 51.99″[2] |
| Apparent magnitude (V) | +5.694[3] |
| Characteristics | |
| Spectral type | F0 IIIn[4] |
| B−V color index | +0.309[3] |
| Astrometry | |
| Radial velocity (Rv) | +19.0±4.3[5] km/s |
| Proper motion (μ) | RA: −80.791 mas/yr[2] Dec.: −44.858 mas/yr[2] |
| Parallax (π) | 13.6180±0.0415 mas[2] |
| Distance | 239.5 ± 0.7 ly (73.4 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.29[1] |
| Details | |
| Mass | 1.47[6] M☉ |
| Radius | 3.20±0.02[2] R☉ |
| Luminosity | 25[1] L☉ |
| Surface gravity (log g) | 3.51[7] cgs |
| Temperature | 7,240±246[6] K |
| Rotational velocity (v sin i) | 109.2[7] km/s |
| Age | 570[6] Myr |
| Other designations | |
| υ1 Cnc, 30 Cancri, BD+24°1940, FK5 2666, HD 72041, HIP 41816, HR 3355, SAO 80229[8] | |
| Database references | |
| SIMBAD | data |
This object has a stellar classification of F0 IIIn, presenting as an F-type giant star.[4] The 'n' suffix indicates "nebulous" absorption lines due to rapid rotation, and it shows a relatively high projected rotational velocity of 109.2 km/s.[7] It is a variable star of unknown type that changes brightness with an amplitude of 0.05 magnitude.[9] The star is about 570[6] million years old and is spinning rapidly with a projected rotational velocity of 109.2 km/s.[7] It has an estimated mass of 1.47[6] times that of the Sun and 3.2 times the Sun's radius.[2] On average, it is radiating 25[1] times the Sun's luminosity from its photosphere at an effective temperature of 7,240 K.[6]