AST 101 Lecture Notes - Lecture 20: Not Proven, Cosmological Principle, Cosmic Distance Ladder

• School: Stony Brook University
• Department: Astronomy
• Course: AST 101
• Professor: Jin Koda

Document Summary

Blue color indicates star formation (new stars outshine others), red color indicates old star presence. Found in groups (up to a dozen) A galaxy"s age and distance are related. Relates to cosmology: study of structure and evolution of universe. Measuring distance between galaxies with cosmological distance ladder. Determine the size of the solar system using a radar. Determine the distance of stars using parallax angle luminosities. When you have brightness and distance you can calculate the. Luminosity for far stars are the same for nearer ones. A standard candle can have luminosity measured without the distance. The apparent brightness of a star cluster"s main sequence tells us distance. Knowing a star cluster"s distance can allow us to find luminosity of all stars (not. Apparent brightness of white dwarf supernovae tells us the distance of the galaxy just main sequence) standard candles. To measure far distance, the brighter the better. White dwarf supernovae can be used as standard candle.