Upsilon Coronae Borealis
Upsilon Coronae Borealis, Latinized from υ Coronae Borealis, is a solitary star in the northern constellation of Corona Borealis. It is a white-hued star that is dimly visible to the naked eye with an apparent visual magnitude of 5.78. The distance to this object is approximately 630 light-years (190 parsecs) based on parallax.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Corona Borealis |
| Right ascension | 16h 16m 44.78733s |
| Declination | +29° 09′ 00.9399″ |
| Apparent magnitude (V) | 5.78 |
| Characteristics | |
| Spectral type | A3V |
| U−B color index | +0.10 |
| B−V color index | +0.07 |
| Astrometry | |
| Radial velocity (Rv) | 0.8±1.0 km/s |
| Proper motion (μ) | RA: +23.474 mas/yr Dec.: −16.644 mas/yr |
| Parallax (π) | 5.1783 ± 0.0777 mas |
| Distance | 630 ± 9 ly (193 ± 3 pc) |
| Absolute magnitude (MV) | −0.72 |
| Details | |
| Mass | 3.06±0.19 M☉ |
| Radius | 1.5 R☉ |
| Luminosity | 151 L☉ |
| Temperature | 8,098 K |
| Rotational velocity (v sin i) | 112 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an A-type main-sequence star with a stellar classification of A3V; a star that is currently fusing its core hydrogen. However, Palmer et al. (1968) had it classed as type A2IV, and thus it may be near or past its main sequence lifetime. It is a suspected variable star of unknown type that has been measured ranging in brightness from magnitude 5.78 down to 5.88.
Upsilon Coronae Borealis has three times the mass of the Sun and about 1.5 times the Sun's radius. It is spinning with a projected rotational velocity of 112 km/s. The star is radiating 151 times the luminosity of the Sun from its photosphere at an effective temperature of 8,098 K.