R Cancri
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 16m 33.82673s |
| Declination | +11° 43′ 34.4691″ |
| Apparent magnitude (V) | 6.07 - 12.3 |
| Characteristics | |
| Spectral type | M6e-M9e |
| U−B color index | 0.49 |
| B−V color index | 1.53 |
| Variable type | Mira |
| Astrometry | |
| Radial velocity (Rv) | 35.42 ± 0.52 km/s |
| Proper motion (μ) | RA: 0.635±0.195 mas/yr Dec.: −10.785±0.106 mas/yr |
| Parallax (π) | 3.9375±0.1792 mas |
| Distance | 854+36 −39 ly (262+11 −12 pc) |
| Details | |
| Mass | 1.67 M☉ |
| Radius | 371±37 R☉ |
| Luminosity | 5,700 L☉ |
| Surface gravity (log g) | −0.608 cgs |
| Temperature | 2,604±300 K |
| Metallicity [Fe/H] | +0.29 dex |
| Other designations | |
| BD+12°1803, HD 69243, HIP 40534, HR 3248, SAO 97694 | |
| Database references | |
| SIMBAD | data |
R Cancri is a Mira variable in the constellation Cancer. Located approximately 250 parsecs (830 ly) distant, it varies between magnitudes 6.07 and 12.3 over a period of approximately 357 days. At its brightest, it is very faintly visible to the naked eye.
Friedrich Magnus Schwerd discovered R Cancri in 1829. It was one of the first variable stars to be discovered.