  | |
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| Constellation | Circinus |
| Right ascension | 15h 17m 30.84945s |
| Declination | −58° 48′ 04.3453″ |
| Apparent magnitude (V) | 4.07 |
| Characteristics | |
| Spectral type | A3 Va |
| U−B color index | +0.09 |
| B−V color index | +0.088±0.007 |
| Astrometry | |
| Radial velocity (Rv) | 9.6±2 km/s |
| Proper motion (μ) | RA: −97.182 mas/yr Dec.: −136.055 mas/yr |
| Parallax (π) | 35.8205±0.2515 mas |
| Distance | 91.1 ± 0.6 ly (27.9 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.64 |
| Details | |
| Mass | 1.96+0.03 −0.01 M☉ |
| Radius | 1.92 R☉ |
| Luminosity | 19 L☉ |
| Surface gravity (log g) | 4.281 cgs |
| Temperature | 8676±33 K |
| Metallicity [Fe/H] | 0.16 dex |
| Rotational velocity (v sin i) | 59 km/s |
| Age | 370–500 Myr |
| Other designations | |
| β Cir, Beta Circini, Beta Cir, CPD−58 5875, FK5 561, GC 20526, GJ 580.1,, GJ 9516, HD 135379, HIP 74824, HR 5670, SAO 242384, PPM 343590 | |
| Database references | |
| SIMBAD | data |
Beta Circini is the second-brightest star in the constellation of Circinus. Its name is a Bayer designation that is Latinized from β Circini, and abbreviated Beta Cir or β Cir. The star has an apparent visual magnitude of approximately 4.07, which is bright enough to be viewed with the naked eye. Based upon an annual parallax shift of 35.8 mas as seen from the Earth, it is located at a distance of 91.1 light-years (27.9 pc) from the Sun.
With a stellar classification of A3 Va, this is an A-type main-sequence star fusing atoms of hydrogen into helium at its core. It is between 370 and 500 million years old and is spinning with a projected rotational velocity of 59 km/s. The star has 1.96 times the mass of the Sun and around 1.9 times the Sun's radius. The star is radiating 19 times the Sun's luminosity from its photosphere at an effective temperature of 8,676 K. It has one known sub-stellar companion.
