Lab Xtra 01 - H-R Diagram 1 .docx - HERTZSPRUNG-RUSSELL...

HERTZSPRUNG-RUSSELL DIAGRAM
INTRODUCTION
In 1910, the astronomical pioneers Henry Norris Russell and Elnar Hertzsprung
independently developed a classification of stars based on the brightness and
surface temperature (or color) of the stars. This analysis was performed by
plotting the data from a large number of stars close to our Sun on a logarithmic
graph of surface temperature and brightness. When temperatures are plotted
against brightness, the stars cluster into groups. From the diagram, it became
clear that the distribution of the brightness and surface temperature of the stars
was not random but allowed the stars to be classified into various groups.
The main classification of stars on the H-R Diagram includes main sequence, red
giants, and white dwarfs. Other classifications sometimes appearing on H-R
Diagrams include red dwarfs, blue dwarfs, blue giants, supergiants, and Cepheid
Variables. These classifications aid in understanding the structure and evolution
of stars.