Circinus, constellation in the southern sky at about 15 hours right ascension and 60° south in declination. Its brightest star is Alpha Circini, with a magnitude of 3.2. The Circinus Galaxy is one of the nearest Seyfert galaxies at a distance of about 13 million light-years. The French astronomer Nicolas Louis de Lacaille formed this constellation in 1754; it represents the compass, or divider, used in navigation and drafting.