• Regulus Regulus is a star in Leo. ##### ########### ############### ################# ################# ################# ############### ########### ##### Type Blue-white main-sequence star Constellation Leo Magnitude 1.4 Spectral type B7V Distance 78 light years Double star components 177.6″ apart You need naked eye from a dark sky Known as Bayer α Leo Yale HR 3982 More information about Regulus Regulus is the dot at the foot of the Sickle and the brightest star in the lion. It sits almost exactly on the line the Sun, Moon and planets follow across the sky, closer to it than any other bright star, so the Moon passes over it and hides it several times in the years when their paths line up. It spins once every sixteen hours, fast enough that it is not round but flattened into an egg, wider across the equator than from pole to pole and noticeably cooler and dimmer around its own middle. At 78 light years it is four stars rather than one. Copernicus coined its name, translating older ones that all said the same thing word for word: Greek Βασιλίσκος, Basiliskos, "little king", Arabic قلب الأسد, Qalb al-Asad, "the lion's heart", and Babylonian Sharru, "the king". Etymology From Latin Reading Regulus Literally little king Bayer lettered the stars of each constellation in his Uranometria of 1603, in order of brightness. He was working from Tycho's magnitudes by eye, and the order he recorded is often wrong. First published in 1930 by Yale astronomer Frank Schlesinger, and maintained since, the Yale Bright Star Catalogue lists every star down to magnitude 6.5. It contains 9,110 stars. where it is tonight: skymap.sh/Regulus