Hertzsprung-Russell Diagram
- Originated in 1911.
- Made by Ejnar Hertzsprung and Henry Norris Russell.
- Hertzsprung plotted absolute magnitude of stars against their color.
- Russell plotted absolute magnitude against spectral class.
- Absolute magnitude is the measure of a star's natural brightness.
- Their results concluded that the relationship between the luminosity and temperature of a star appeared to fall into distinct groups, as shown in the pictures above.
Quiz
1. When was the HR Diagram first made?
2. What is Hertzsprung's first name?
3. Who plotted absolute magnitude against natural brightness?
4. What is the measure of a star's natural brightness?
5. Who plotted the absolute value of stars against their color?