Background
The Hertzsprung-Russell diagram, often called the HR diagram, is a crucial tool for studying how stars change over time. Created in the early 1900s by two scientists, Ejnar Hertzsprung and Henry Norris Russell, this diagram shows the relationship between a star's temperature and color and its brightness, or luminosity.
Every star develops through specific stages based on its initial mass, which affects its internal structure and energy production. As a star goes through these stages, its temperature and luminosity change.
This movement can be tracked on the HR diagram, showing how the star evolves over time. The HR diagram is powerful because astronomers can determine a star's internal structure and its stage of evolution just by looking at where it is located on the diagram.
