Alpha Pictoris
Alpha Pictoris (α Pic, α Pictoris) is the brightest star in the southern constellation of Pictor. It has an apparent visual magnitude of 3.27, which is bright enough to be viewed from urban areas in the southern hemisphere. This star is close enough for its distance to be measured using parallax shifts, which yields a value of roughly 97 light-years (30 parsecs) from the Sun, with a 5% margin of error. Alpha Pictoris has the distinction of being the south pole star of the planet Mercury.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pictor |
| Right ascension | 06h 48m 11.45512s |
| Declination | −61° 56′ 29.0008″ |
| Apparent magnitude (V) | 3.27 |
| Characteristics | |
| Spectral type | A8 Vn kA6 |
| U−B color index | +0.13 |
| B−V color index | +0.21 |
| Astrometry | |
| Radial velocity (Rv) | +20.6 km/s |
| Proper motion (μ) | RA: –66.07 mas/yr Dec.: +242.97 mas/yr |
| Parallax (π) | 33.78 ± 1.78 mas |
| Distance | 97 ± 5 ly (30 ± 2 pc) |
| Absolute magnitude (MV) | 0.86 |
| Orbit | |
| Period (P) | 1618+1407 −325 days |
| Semi-major axis (a) | 36+15 −2 mas |
| Eccentricity (e) | 0.39+0.35 −0.17 |
| Inclination (i) | 118±3° |
| Longitude of the node (Ω) | 24±5° |
| Periastron epoch (T) | 953+707 −640 |
| Argument of periastron (ω) (secondary) | 92+22 −44° |
| Details | |
| Mass | 2.04 M☉ |
| Radius | 1.6 R☉ |
| Luminosity | 13 L☉ |
| Surface gravity (log g) | 3.48 cgs |
| Temperature | 7530 K |
| Metallicity [Fe/H] | –0.11 dex |
| Rotational velocity (v sin i) | 206 km/s |
| Age | 660 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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