V Coronae Borealis
Mira-type long period variable star in the constellation Corona Borealis
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V Coronae Borealis (V CrB) is a Mira-type long period variable star and carbon star in the constellation Corona Borealis. Its apparent magnitude varies between 6.9 and 12.6 over a period of 357 days.[4]
V Coronae Borealis in optical light | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Corona Borealis |
| Right ascension | 15h 49m 31.31220s[1] |
| Declination | +39° 34′ 17.8926″[1] |
| Apparent magnitude (V) | 6.9 - 12.6[2] |
| Characteristics | |
| Evolutionary stage | AGB[3] |
| Spectral type | C6,2e(N2e)[4] |
| Variable type | Mira[2] |
| Astrometry | |
| Proper motion (μ) | RA: +5.905 mas/yr[1] Dec.: −15.089 mas/yr[1] |
| Parallax (π) | 1.1378±0.0238 mas[1] |
| Distance | 2,870 ± 60 ly (880 ± 20 pc) |
| Details[5] | |
| Radius | 750[a] R☉ |
| Luminosity | 5,300 L☉ |
| Temperature | 1,800 K |
| Other designations | |
| V CrB, BD+40 2929, HD 141826, HIP 77501, SAO 64929[6] | |
| Database references | |
| SIMBAD | data |
Based on a period of 357 days, the absolute magnitude of V Coronae Borealis has been calculated to be -4.62.[8] It is estimated to be 880 pc (2,900 ly) from Earth based on parallax, has a luminosity of 5,300 L☉ and a rather cool effective temperature of 1,800 K, these implying a very large radius of about 750 R☉, making V Coronae Borealis one of the largest stars so far discovered.[5] If placed in the center of the Solar System, its size would engulf all rocky planets and reach parts of the asteroid belt.
Notes
- Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
