Some Obscurish facts
#1321
Sirius is the brightest star in the night sky. However, it is a dwarf star and not particularly luminous in absolute terms - it appears brilliant because it is less than nine light years away. By comparison, the star Deneb in Cygnus appears much fainter than Sirius in the sky, but actually a supergiant thousands of times more luminous than Sirius - it appears fainter because it is more than three thousand light years away.
Sirius is the brightest star in the night sky. However, it is a dwarf star and not particularly luminous in absolute terms - it appears brilliant because it is less than nine light years away. By comparison, the star Deneb in Cygnus appears much fainter than Sirius in the sky, but actually a supergiant thousands of times more luminous than Sirius - it appears fainter because it is more than three thousand light years away.