82 Cancri
Star in the constellation Cancer
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82 Cancri is a solitary,[4] orange-hued star in the zodiac constellation of Cancer. It has the Bayer designation Pi2 Cancri, which is Latinized from π2 Cancri; 82 Cancri is the star's Flamsteed designation. The star lies just a degree to the south of the ecliptic.[10] With an apparent visual magnitude of +5.33,[3] it is dimly visible to the naked eye on a dark night. This star is located at a distance of approximately 574 light-years (176 pc) from the Sun based on parallax measurements. At that range, the visual magnitude is diminished by an extinction of 0.10 magnitudes due to interstellar dust.[11] It is drifting further away with a radial velocity of +27.5 km/s.[5]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer[1] |
| Right ascension | 09h 15m 13.852s[2] |
| Declination | +14° 56′ 29.43″[2] |
| Apparent magnitude (V) | +5.33[3] |
| Characteristics | |
| Evolutionary stage | red giant branch[2] |
| Spectral type | K1 III[4] |
| U−B color index | +1.31[3] |
| B−V color index | +1.32[3] |
| Astrometry | |
| Radial velocity (Rv) | +27.49±0.19[5] km/s |
| Proper motion (μ) | RA: −41.018 mas/yr[2] Dec.: −11.304 mas/yr[2] |
| Parallax (π) | 5.6869±0.0902 mas[2] |
| Distance | 574 ± 9 ly (176 ± 3 pc) |
| Absolute magnitude (MV) | −0.98[1] |
| Details | |
| Mass | 2.56±0.13[6] M☉ |
| Radius | 31.32+0.85 −0.64[2] R☉ |
| Luminosity | 435+10 −12[2] L☉ |
| Surface gravity (log g) | 2.04±0.02[2] cgs |
| Temperature | 4,703+18 −27[2] K |
| Metallicity [Fe/H] | −0.195±0.099[7] dex |
| Rotational velocity (v sin i) | 1.3±1.0[8] km/s |
| Other designations | |
| π2 Cnc, 82 Cancri, BD+15°2009, FK5 2733, HD 79554, HIP 45410, HR 3669, SAO 98456[9] | |
| Database references | |
| SIMBAD | data |
This is an evolved K-type giant star with a stellar classification of K1 III,[4] having exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. The star 2.6[6] times the Sun's mass and has expanded to 31[2] times the girth of the Sun. It is spinning slowly with a projected rotational velocity. This star is radiating 435 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,703 K.[2] Based on its abundance of iron, the star has a lower abundances of heavier elements than the Sun.[7]