Mile Markers
/
RSS Feed
Mile markers in the distant universe
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.
Shopping Cart