The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

Standard Candles vs Doppler Effect

When finding distances to far away galaxies from the earth, how do we know whether to use Standard Candles or the Doppler effect+Hubble's Law?
Original post by Ellie.Ginger
When finding distances to far away galaxies from the earth, how do we know whether to use Standard Candles or the Doppler effect+Hubble's Law?


Well you have to use what you can find. I suggest reading an article on the cosmic distance ladder if you haven't already...
http://www.iop.org/resources/topic/archive/cosmic/index.html
the important point is that there is an amount of crossover between parallax and cepheid standard candle. comparing the light curves of nearby cepheids whith their parallax is what allows you to get the standard candle method calibrated so that we can use it on distant cepheids where parallax isn't useful anymore... and the same is true between every other pair of rungs on the ladder.

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you