the truth is out there

[informashun]

sirius or the dog star is the brightest star in our galaxy and with the right conditions can be seen in daylight.
my question is why is the sun not the brightest star ?

[jake-the-peg]

The sun is the brightest star (in relative terms) that we can see but we often ignore it when talking about stars because it's our one.

Sirius is the brightest star that we can normally see but the occasional supernova has far outshone it.

When you say in our galaxy it seems that you may be confusing what we would call apparent magnitude (the brightness that it seems to us) with absolute magnitude (how bright a star actually is or would appear to be from a standard distance.)

Sirrius has quite a high absolute magnitude compared to the Earth (1.4 to the Earth's 4.8) but it's very close to us Rigel however seems less bright but has an absolute magnitude of -7

In case you've not noticed the lower the number the brighter it is

[mrs_overall]

Just as an aside...I was recently in a quiz and one of the questions was "dog star." I put the answer down as Sirius. I was a bit miffed when it was marked as wrong. The answer they wanted was "Lassie."

[mibn2cweus]

mrs_overall, Welcome to human race!

jake-the-peg, I'm quite sure you meant the Sun's (not Earth's) absolute magnitude is 4.83? In comparison Sirius with an absolute magnitude of 1.4 burns about 23.5 times brighter than our Sun while Rigel at -7 is an astounding 50000 plus times brighter than the Sun when viewed from an equal distance.

Comparing apparent magnitude the Sun�s magnitude is -26.73 and Sirius�s apparent magnitude is -1.5 making the Sun 12 359 474 334 . 5 times brighter! No wonder it far outshines half the stars in the galaxy (those on the daylight side of the Earth).