Why does Sirius shine so brightly in the night sky and change colour alot?

Answer 1

Sirius has a mass of about 2.1 times our sun, its larger and hotter (therefore whiter) than our sun, and only 8.6 light years away.
All this combines to make this star the brightest star in our skies.
The colour changes are likely due to turbulence and dust particles in our atmosphere. To the naked eye, it often appears to be flashing with red/white/blue hues when near the horizon.
Some people have reported Sirius as red or orange, but there is no scientific evidence that the star is variable in colour or temperature.

Answer 2

Well it is the brightest star (except for the sun) but it is fairly low in the sky when seen from the UK. The light seen from Sirius is affected by the Earths atmosphere which can make it appear to move around,twinkle and change colour.

Answer 3

Sirius shine so brightly because it is a hotter sun than ours so it puts out more light. Plus, it is relatively close to us as stars go, only 8 light years away (compared to 4.3 for the closest star). So all that adds up to Sirius being the brightest star we can see with the naked eye.

The reason it changes color is because it twinkles. This is cause by cold and warm cells of air high in our atmosphere that act like tiny differing lenses. These scatter the light in different directions, amounts and colors.

Answer 4

Sirius is the brightest star (in the negative 1 or 2 level of brightness) in the night sky, but is not only one star. A small dwarf star is orbiting Sirius. I believe this could be one of the reasons for the change in color, but in my rudimentary observations the star is primary white.

Answer 5

I don't know, i thought he was dead.

Answer 6

he's dead