Khan Academy Static

We've talked a lot about distances to stars, but how do we know? Stellar parallax--which looks at how much a star shifts in the sky when Earth is at various points in its orbit--is the oldest technique we have for measuring how far stars are. It is great for "nearby" stars even with precise instruments (i.e, in our part of our galaxy). To measure distance further, we have to start thinking about Cepheid variables (other tutorial).

10664_Parsec_definition.html

10660_Parallax_in_observing_stars.html

10661_Stellar_parallax.html

10662_Stellar_distance_using_parallax.html

10663_Stellar_parallax_clarification.html