Sirius

Brightest star in the night sky, 8.6 light years from the Sun in the constellation Canis Major. Sirius is a double star: Sirius A is a white star with a mass 2.3 times that of the Sun, a diameter 1.8 times that of the Sun, and a true luminosity of 23 Suns. It is orbited every 50 years by a white dwarf, Sirius B, also known as the Pup.

Sirius B is an eighth-magnitude companion which is sometimes known as ‘the Dark Companion’ as it was first detected in the 19th century by German astronomer Friedrich Bessel from its gravitational effect on the proper motion of Sirius A. ‘Dog Star’ is the alternative name for Sirius, dating back to ancient Egypt. The unpleasantness of the hot summer season known as the ‘dog days’ was attributed to the influence of Sirius being in conjunction with the Sun. Sirius B was seen for the first time in 1862 but it was only in the 1920s that it was recognized as the first known example of a white dwarf.

The name ‘Sirius’ is derived from the Greek word for ‘sparkling’. In ancient Egypt, where its hieroglyph was a dog, its reappearance in the early morning sky heralded the annual rising of the Nile.

Sirius

Work by Stockhausen for soprano, baritone, and ensemble, dedicated to American pioneers and astronauts. It was first performed in Washington, DC, on 18 July 1976.