53 Cancri
Red star in the constellation Cancer
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53 Cancri is a variable star in the zodiac constellation Cancer, located around 960 light years from the Sun. It has the variable star designation BO Cancri; 53 Cancri is the Flamsteed designation. This object is a challenge to view with the naked eye, having an apparent visual magnitude around 6. It is around 960 light years away.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 52m 28.58850s[2] |
| Declination | +28° 15′ 32.9851″[2] |
| Apparent magnitude (V) | 5.9 - 6.4[3] |
| Characteristics | |
| Evolutionary stage | red giant |
| Spectral type | M3 III[4] |
| B−V color index | 1.552±0.010[4] |
| Variable type | SRb[3] |
| Astrometry | |
| Radial velocity (Rv) | +13.82±0.29[4] km/s |
| Proper motion (μ) | RA: −15.212[2] mas/yr Dec.: −7.961[2] mas/yr |
| Parallax (π) | 3.4133±0.1685 mas[2] |
| Distance | 960 ± 50 ly (290 ± 10 pc) |
| Details | |
| Radius | 87[2] R☉ |
| Luminosity | 1,175[2] L☉ |
| Temperature | 3,622[2] K |
| Other designations | |
| 53 Cnc, BO Cancri, BD+28°1659, HD 75716, HIP 43575, HR 3521, SAO 80476[5] | |
| Database references | |
| SIMBAD | data |
The star is moving further away from the Earth with a heliocentric radial velocity of +14 km/s.[4] 53 Cancri is an aging red giant on the asymptotic giant branch[6] and has a stellar classification of M3 III.[4] It has expanded to 87 times the radius of the Sun, and its bolometric luminosity is over a thousand times higher than the Sun's at an effective temperature of 3,622 K.[2]
In 1969, Olin Jeuck Eggen announced that small vaiarions in the brightness of 53 Cancri had been detected.[7] For that reason it was given a variable star designation in 1972.[8] 53 Cancri is a semiregular variable that varies between magnitude 5.9 and 6.4 with a period of 27 days.[3] There is a suspected second period of 270 days.[9]