Canis Maior
Sirius is a white star with reddish flashes. «Talis ei custos aderit Canis ore timendo. Ore vomit flammam, membris contemptior ignis» (Germanicus, Arati Phaenomena, lines 333-334). In the Almagest it is «a star set in the mouth, the brightest one, called 'the Dog' and red-coloured». In the texts of the Anonymous of the year 379 the nature of Mars is attributed to it, but Ptolemy says that the stars of the Dog agree with the star of Venus, but the bright star which is in the mouth agrees with the star of Jupiter and partly with Mars ; (Tetrabiblos I,9).