- Achernar (stars.astro.illinois.edu)
ACHERNAR (Alpha Eridani). There are 22 classical “first magnitude” stars in the sky. Of these, nine are so bright that in modern times they had to be placed into even brighter categories, seven into “zeroth” magnitude (the brightest of which is Alpha Centauri) and two (Canopus and Sirius) into the exclusive “minus-first magnitude” group. Of these nine, Achernar ranks last, right behind Procyon in Canis Minor and just beating out Hadar in southern Centaurus.
- Achernar (Wikipedia)
Achernar is the brightest star in the constellation of Eridanus and the ninth-brightest in the night sky. It has the Bayer designation Alpha Eridani, which is Latinized from α Eridani and abbreviated Alpha Eri or α Eri. The name Achernar applies to the primary component of a binary system. The two components are designated Alpha Eridani A (the primary) and B (the secondary), with the latter known informally as Achernar B. As determined by the Hipparcos astrometry satellite, this system is located at a distance of approximately 139 light-years (43 parsecs) from the Sun.
