How does standard candle work?

1. Apr 17, 2008

hobobobo

I'm kinda confused about how standard candle works. I know they use type 1 supernovae since their luminosity is the same everywhere but how do scientists know how far a star is if their luminosity is the same everywhere. I don't really get how they measure distance with it. Can someone please explain to me! thanx^^

2. Apr 17, 2008

Janus

Staff Emeritus
If the luminosity of two objects are the same they will appear to be equally bright when viewed from a equal distance. They will not appear to be equally bright when viewed from different distances. Thus if we see two type 1 supernovae, and one is brighter than the other, we know that it is closer to us than the other. And by how much brighter we can tell how much nearer it is.

3. Apr 17, 2008

Nabeshin

I think that scientists can infer that all type I supernova have about the same luminosity because of the physics behind this specific type of supernova. I believe it only occurs with a certain mass of star, so the explosions are relatively the same intensity for all of them. The other half is what Janus said :)

4. Apr 17, 2008

hobobobo

hmmmm I see because I was confused of luminosity and brightness like the difference from those two.