Cepheid variable One of an important class of variable stars that pulsate in a regular manner, accompanied by changes in luminosity. Cepheids can expand and contract up to 30% in each cycle. The average luminosity is 10,000 times that of the Sun. Cepheids became important in cosmology (1912) when US astronomer Henrietta Leavitt discovered a relationship between the period of light variation and the absolute magnitude of a cepheid. This period-luminosity law enables the distances of stars to be ascertained.
More From encyclopedia.com
Ejnar Hertzsprung , Hertzsprung, Ejnar Hertzsprung, Ejnar astronomy. Hertzprung’s father, Severin Hertzsprung, had a graduate degree in astronomy from the University of… Variable Star , Variable stars are stars that vary in brightness over time. In most cases, these changes occur very slowly over a period of months or even years. In… Henrietta Leavitt , Henrietta Swan Leavitt Henrietta Swan Leavitt Henrietta Swan Leavitt (1868-1921) was an American astronomer of the first magnitude. Her research resu… William Frederick Herschel , Herschel, William Herschel, William (b. Hannover, Germany, 15 November 1738; d. Observatory House, Slough, Buckinghamshire, England, 25 August 1822)… Friedrich Wilhelm Bessel , Bessel, Friedrich Wilhelm Bessel, Friedrich Wilhelm astronomy, geodesy, mathematics. Bessel’s father was a civil servant in Minden; his mother was th… Hertzsprung-russell Diagram , Hertzsprung-Russell Diagram A Hertzsprung-Russell diagram, or HR diagram, is a graph of stellar temperatures (plotted on the horizontal axis) and lum…
About this article
All Sources -
Updated Aug 24 2016 About encyclopedia.com content Print Topic
You Might Also Like