Canopus, in astronomy, 2d brightest star in the sky, located in the constellation Carina, which is part of the ancient constellation Argo Navis; Bayer designation α Carinae; 1992 position R.A. 6h23.8m, Dec. - 52°41−. It has an apparent magnitude of - 0.72, second only to Sirius among the bright stars. Canopus is a yellowish-white giant star of spectral class F0 I-II. Its distance is about 100 light-years. It is probably named after the ancient Egyptian city of Canopus.