Star

Sirius

Also known as ALPHA CANIS MAJORIS · DOG STAR · SHIRA · AL SHIRA

The brightest star in the night sky.

Visible tonight?

Up now · alt 36° S

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Rises: 22:49
Transit: 04:01
Sets: 09:16

Binary system in Canis Major. Its companion, Sirius B, is a white dwarf.

Observing

Unmistakable in winter skies, twinkling fiercely. Follow Orion's belt down-left to find it.

Observing from Chitral

Sirius culminates around 33° altitude from Chitral — low enough that its light cuts through a lot of atmosphere and scintillates in violent flashes of red, blue and green. That is atmospheric dispersion, not the star. Its white-dwarf companion, Sirius B, needs a 250 mm telescope and exceptional seeing.

History & culture

The heliacal rising of Sirius set the Egyptian calendar and predicted the Nile flood. Its name comes through Arabic al-shi'ra.