Alpha Circini
  | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Circinus |
| Right ascension | 14h 42m 30.41958s |
| Declination | −64° 58′ 30.4934″ |
| Apparent magnitude (V) | 3.18 - 3.21 |
| Characteristics | |
| Spectral type | A7 Vp SrCrEu |
| U−B color index | +0.12 |
| B−V color index | +0.24 |
| Variable type | roAp |
| Astrometry | |
| Radial velocity (Rv) | +7.2 km/s |
| Proper motion (μ) | RA: −192.53 mas/yr Dec.: −233.51 mas/yr |
| Parallax (π) | 60.35±0.14 mas |
| Distance | 54.0 ± 0.1 ly (16.57 ± 0.04 pc) |
| Absolute magnitude (MV) | +2.18 |
| Details | |
| Mass | 1.5–1.7 M☉ |
| Radius | 1.967±0.066 R☉ |
| Luminosity | 10.51±0.60 L☉ |
| Surface gravity (log g) | 4.1 cgs |
| Temperature | 7,500 K |
| Metallicity [Fe/H] | 0.13 dex |
| Rotation | 4.4790±0.0001 days |
| Rotational velocity (v sin i) | 13.0±1.5 km/s |
| Age | ~12 Myr |
| Other designations | |
| Xami, 17 G. Cir, α Cir, CD−64°867, GJ 560, HD 128898, HIP 71908, HR 5463, SAO 252853 | |
| Database references | |
| SIMBAD | A |
| B | |
Alpha Circini is a variable star in the faint, southern, circumpolar constellation of Circinus. It has the proper name Xami; Alpha Circini is its Bayer designation, which is Latinized from α Circini and abbreviated Alpha Cir or α Cir. At an apparent visual magnitude of 3.19, it is the brightest star in the constellation and can be readily seen with the naked eye from the southern hemisphere to as far north as 25° north latitude. Parallax measurements of this star yield an estimated distance of 54.0 light-years (16.6 parsecs) from the Earth. There is a K dwarf companion star, Alpha Circini B.