S Coronae Borealis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Corona Borealis |
| Right ascension | 15h 21m 23.9561s |
| Declination | +31° 22′ 02.573″ |
| Apparent magnitude (V) | 5.3 – 13.6 |
| Characteristics | |
| Spectral type | M7e |
| U−B color index | 0.36 |
| B−V color index | 1.71 |
| Variable type | Mira |
| Astrometry | |
| Radial velocity (Rv) | -5.12 km/s |
| Proper motion (μ) | RA: -7.73 mas/yr Dec.: -13.03 mas/yr |
| Parallax (π) | 2.39±0.17 mas |
| Distance | 418+21 −18 pc |
| Absolute magnitude (MV) | -0.8±0.3 |
| Details | |
| Mass | 1.34 M☉ |
| Radius | 308 (537–664) R☉ |
| Luminosity | 5,897 L☉ |
| Temperature | 2,864 (2,350–2,600) K |
| Other designations | |
| S Coronae Borealis, HD 136753, BD+31°2725, HIP 75143, GC 20662, SAO 64652, GSC 02563-01338, DO 15223, AAVSO 1517+31 | |
| Database references | |
| SIMBAD | data |
S Coronae Borealis (S CrB) is a Mira variable star in the constellation Corona Borealis. Its apparent magnitude varies between 5.3 and 13.6, with a period of 360 days—just under a year. Within the constellation, it lies to the west of Theta Coronae Borealis, and around 1 degree southeast of the eclipsing binary star U Coronae Borealis. When it is near its maximum brightness, it can be seen with the naked eye, under good observing conditions.