Which is the brightest star in the night sky as seen from the earth?

The correct answer is B, Sirius, also called the Dog Star, in the constellation Canis Major. It appears brightest because it is both luminous and close, about 8.6 light years away, and it is in fact a binary system with a white dwarf companion. Option A, Polaris, is only a moderately bright star; its importance is that it lies nearly above the north pole of the earth, so it marks north and appears almost fixed while the sky turns. Option C, Canopus, in the constellation Carina, is the second brightest star of the night sky and is called Agastya in Indian tradition, which makes it a good distractor. Option D, Vega, in Lyra, is among the brightest stars of the northern sky and was once used as the standard of magnitude. Candidates should remember that the Sun is the brightest star in our sky but is excluded when the question says night sky.