Beta Coronae Australis
Star in the constellation Corona Australis
From Wikipedia, the free encyclopedia
Beta Coronae Australis is a solitary star[15] located in the southern constellation Corona Australis. Its name is a Bayer designation that is Latinized from β Coronae Australis, and abbreviated Beta CrA or β CrA. This body is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.10.[3] The star is located around 470 light years distant from the Sun based on parallax,[2] and is drifting further away with a radial velocity of 2.7 km/s.[6] At its current distance, Beta CrA's brightness is diminished by 0.29 magnitudes due to interstellar dust.[16]
 | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Corona Australis[1] |
| Right ascension | 19h 10m 01.75580s[2] |
| Declination | −39° 20′ 26.8644″[2] |
| Apparent magnitude (V) | 4.10±0.01[3] |
| Characteristics | |
| Spectral type | K0 II/III CN1.5[4] |
| U−B color index | +1.07[5] |
| B−V color index | +1.20[5] |
| R−I color index | +0.61[5] |
| Astrometry | |
| Radial velocity (Rv) | 2.7±0.7[6] km/s |
| Proper motion (μ) | RA: +4.37 mas/yr[2] Dec.: −36.65 mas/yr[2] |
| Parallax (π) | 6.88±0.25 mas[2] |
| Distance | 470 ± 20 ly (145 ± 5 pc) |
| Absolute magnitude (MV) | −1.71[1] |
| Details | |
| Mass | 5.17±0.26[7] M☉ |
| Radius | 38.5±1.9[8] R☉ |
| Luminosity | 614±33[9] L☉ |
| Surface gravity (log g) | 1.26[10] cgs |
| Temperature | 4,575±55[11] K |
| Metallicity [Fe/H] | +0.24[10] dex |
| Rotational velocity (v sin i) | 6.2±2[12] km/s |
| Other designations | |
| β CrA, 46 G. Coronae Australis[13], CD−39°13146, CPD−39°8327, GC 26380, HD 178345, HIP 94160, HR 7259, SAO 211005, PPM 298639[14] | |
| Database references | |
| SIMBAD | data |
Beta CrA has a stellar classification of K0 II/III CN1.5,[4] indicating that it is an evolved K-type star with the blended luminosity class of a bright giant and a regular giant star. The suffix CN1.5 indicates that the object has an anomalous overabundance of cyano radicals in its spectrum, making it a CN star. Having exhausted the supply of hydrogen at its core, the star has expanded to 39 times the Sun's girth.[9] It has 5.17 times the mass of the Sun shines with a luminosity 614 times that of the Sun[9] from its photosphere at a surface temperature of 4,575 K.[11] Beta CrA is metal enriched (174% solar iron abundance[10]) and spins modestly with a projected rotational velocity of 6.2 km/s.[12]