The Origin of the Universe
A survey of the evidence
Introduction
Measurement Overview
Parallax Distances
Star Sizes and Absolute Magnitudes
Cepheid Distances
Type 1a Supernovae Distances
Redshift Velocities and Distances
Age of the Stars in Globular Clusters
The Oldest White Dwarfs
The Cosmic Microwave Background
Conclusion
Among the stars for which we have precise absolute magnitudes is a class called Cepheid variables. They pulsate regularly in brightness with period lengths related to their size and absolute magnitudes. They are luminous stars that can be seen across the galaxy and in nearby galaxies. Via Cepheids, astronomers have determined distances to galaxies out to 100 million light years - the resolution limit for galactic Cepheids by current telescopes.