(via syc0rax)
Sirius, known in ancient Egypt as Sopdet, is recorded in the earliest astronomical records. During the era of the Middle Kingdom, Egyptians based their calendar on the heliacal rising of Sirius, namely the day it becomes visible just before sunrise after moving far enough away from the glare of the Sun.
In 1844 German astronomer Friedrich Bessel deduced from changes in the proper motion of Sirius that it had an unseen companion. Nearly two decades later, on January 31, 1862, American telescope-maker and astronomer Alvan Graham Clark first observed the faint companion, which is now called Sirius B, or affectionately “the Pup”.