Circinus, The Compass, is a Southern
Hemisphere constellation introduced by Nicolas Louis de Lacaille in the
mid-eighteenth century. Only seven Bayer stars
are brighter than sixth magnitude.
Alpha Circini is a visual double with faint companion: 3.2, 9; PA
Gamma Circini is a very close double of contrasting stars (blue
and yellow): 5, 5; PA 49º, separation 0.9"
Circinus has two variables among the Bayer stars:
Alpha Circini is an alpha CV type variable: 3.18-3.21.
Theta Circini is a gamma Cas variable: 5.02-5.44.
Deep Sky Objects:
Circinus has no deep sky objects of any interest.