Bootis alpha

See also: Arcturus

Arcturus ( α Bootis according to the Désignation from Bayer) is a the star red, at the end of the lifetime, most brilliant of the constellation of the Bouvier.

The diameter of Arcturus is of 20 times that of the Sun, its magnitude is of -0,04 and its distance to the sun is of 37 light-years. By prolonging the tail of the Large Ourse, one locates this brilliant and orange star easily.

Arcturus is the most luminous star of the northern hemisphere. But although it releases 180 times more energy than the Sun, it appears only 110 times more luminous because most of the light which it emits is formed of infra-reds which the human eye does not distinguish. It could be a question of a double star but the other star is 20 times less luminous and very difficult to observe. Arcturus owes its name to the Greek old “Arktouros” who means “the guard of the bear” because of his proximity with Large Ourse and Small Ourse.

See too

List of most brilliant stars

Reference

External bond

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