Cosmic Distance Ladder: Cepheid Variables

An introduction to the class of variable stars known as Cepheid variables and their use as standard candles for measuring cosmic distances. Covers Henrietta Leavitt's discovery of the relationship between period and luminosity and an example of how this was used to measure the distance to the Andromeda galaxy which proved the existence of other galaxies.

Here are the links to Henrietta Leavitt's key papers on Cepheid variables:
http://adsabs.harvard.edu/abs/1908AnHar..60...87L
http://adsabs.harvard.edu/abs/1912HarCi.173....1L

And a recent paper on V1 in the Andromeda galaxy including graphs of the light curves
http://arxiv.org/abs/1111.0262

Just click on the pdf link to see the documents

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Видео Cosmic Distance Ladder: Cepheid Variables канала PhysicistMichael