Cosmic Distance Ladder – Part 3

How I See It

Part 3 of the Cosmic Distance Ladder series is a little longer than the previous two. We will see which tools astronomers use to find the distances to objects much beyond our own home galaxy. There will be some discussion of supernovae and black holes.

The first part of this post advances up the distance ladder by telling the remarkable story of Henrietta Swan Leavitt. Her contributions to the study of Cepheid variable stars led to a method to know intergalactic distances millions of light years from our Milky Way. The previous Cosmic Distance Ladder – Part 2 discussed stellar parallax and main sequence fitting as methods to determine distances to objects within the confines of the Milky Way vicinity. If you wish to see parts 1 & 2, they are linked here and here.

The Harvard Calculators

Henrietta was the daughter of Congregational church minister George Roswell Leavitt and Henrietta Swan…

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