Dog days Dog days The dog days or are the hot, sultry days of summer. They were historically the period following the heliacal rising of the star system Sirius, which Greek and Roman astrology connected with heat, drought, sudden thunderstorms, lethargy, fever, mad dogs, and bad luck. They are now taken to be the hottest, most uncomfortable part of summer in the Northern Hemisphere. The English name is a calque of the Latin "" (."the puppy days"), itself a calque of the Greek "kynádes hēmérai" (, "dog days"). The Greeks knew the star α Canis Majoris by several names, including Sirius (,
Sirius to have traditional astronomical knowledge about Sirius that would normally be considered impossible without the use of telescopes. In 1938 Marcel Griaule produced his dissertation and received his doctorate degree from the École pratique des hautes études (EPHE) based on his research work with the Dogon. According to Griaule's books "Conversations with Ogotemmêli" 1965 and "The Pale Fox" 1972 they knew about the fifty-year orbital period of Sirius and its companion prior to western astronomers. They also refer to a third star accompanying Sirius A and B. Robert Temple's 1976 book "The Sirius Mystery", credits them with knowledge of the