Cepheid Variable

An unstable star that pulses in and out, causing a periodic change in brightness. In 1912, Henrietta Leavitt discovered what is known as the period-luminosity relationship for Cepheid variables, by which the period of the brightness change is related to the luminosity, and therefore the distance, of the star. An astronomer can plot a Cepheid's changing brightness to create a light curve for the star. The distance to the Cepheid variable is then obtained by measuring the period of the light curve, which shows the length of each pulsation.

Radio Programs

Delta Cephei A surprise from a well-known star Monday, August 3, 2015
More Polaris A “hiccup” for the North Star Friday, October 24, 2014
Polaris III Poking into the life of a famous star Thursday, February 21, 2013
Polaris II The un-steady beat of the North Star Wednesday, February 20, 2013


©2015 The University of Texas McDonald Observatory