Sirius astrological symbol was listed by Heinrich Cornelius Agrippa. Many cultures have historically attached special significance to Sirius, particularly in relation to dogs. It is often colloquially called the "Dog Star" as the brightest star of Canis Major, the "Great Dog" constellation. It was classically depicted as Orion's dog. The Ancient Greeks thought that Sirius's emanations could affect dogs adversely, making them behave abnormally during the "dog days," the hottest days of the summer. The Romans knew these days as "dies caniculares", and the star Sirius was called Canicula, "little dog." The excessive panting of dogs in hot weather was thought
Sirius the star when rising left the viewer with the impression that it was red. To the naked eye, it often appears to be flashing with red, white and blue hues when near the horizon. With an apparent magnitude of −1.46, Sirius is the brightest star system in the night sky, almost twice as bright as the second brightest star, Canopus. From Earth, Sirius always appears dimmer than Jupiter and Venus, as well as Mercury and Mars at certain times. Sirius is visible from almost everywhere on Earth, except latitudes north of 73° N, and it does not rise very high