| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 25m 49.87726s[1] |
| Declination | +17° 02′ 46.5717″[1] |
| Apparent magnitude (V) | 6.11[2] |
| Characteristics | |
| Spectral type | F6 V[3] |
| B−Vcolor index | 0.448±0.005[2] |
| Astrometry | |
| Radial velocity (Rv) | +37.56±0.13[1] km/s |
| Proper motion (μ) | RA: −191.567[1]mas/yr Dec.: −151.554[1]mas/yr |
| Parallax (π) | 21.9803±0.0321 mas[1] |
| Distance | 148.4 ± 0.2 ly (45.50 ± 0.07 pc) |
| Absolute magnitude (MV) | 2.85[2] |
| Details | |
| 25 Cnc A | |
| Mass | 1.51[4] M☉ |
| Radius | 2.0[1] R☉ |
| Luminosity | 6.60[2] L☉ |
| Surface gravity (log g) | 4.01[5] cgs |
| Temperature | 6,487[5] K |
| Metallicity[Fe/H] | −0.10[5] dex |
| Rotational velocity (v sin i) | 37.74±0.55[6] km/s |
| Age | 2.50[5] Gyr |
| 25 Cnc B | |
| Mass | 0.34[4] M☉ |
| Other designations | |
| d2 Cnc,25 Cnc,BD+17°1842,HD 71030,HIP 41319,HR 3299,SAO 97806,WDS 08258+1703[7][8] | |
| Database references | |
| SIMBAD | data |
25 Cancri is acommon proper motion[4]star system in thezodiacconstellation ofCancer, located around 148 light-years away from theSun. It has theBayer designationd2 Cancri (d2 Cnc);25 Cancri (25 Cnc) is theFlamsteed designation. It is near the lower limit of visibility to the naked eye in good viewing conditions, appearing as a dim, yellow-white-huedstar with a combinedapparent visual magnitude of 6.11.[2] The pair have a relatively highproper motion, traversing thecelestial sphere at an angular rate of0.245″ per year.[9] It is moving further from the Earth with a heliocentricradial velocity of +38 km/s.[1]
Based upon astellar classification of F6 V,[3] the brighter component is anF-type main-sequence star that is generating energy throughhydrogen fusion at its core. Cowley (1976) listed a class of F5 IIIm?,[10] which suggests it may be anAm star. However, this has not been confirmed.[6] It is about 2.5[5] billion years old with 1.51[4] times themass of the Sun. The star is radiating 6.6[2] times theSun's luminosity from itsphotosphere at aneffective temperature of6,487 K.[5]
The companion is 4.19 magnitudes fainter than the primary, and lies at anangular separation of16.798″ along aposition angle of 310°, as of 2013.[8] If the pair aregravitationally bound, then they orbit each other with aperiod of around 4.05 million years.[4]
