Hertzsprung-Russell Diagrams
Physics: AQA A Level, topic 9.2.5
Hertzsprung-Russell (HR) Diagrams
The Hertzsprung-Russel diagram (HR diagram) is a plot of luminosity against temperature.
HR diagram
- Most stars have a position on the HR diagram.
- On this diagram, the Sun is at a luminosity of 1 and is a G class star.
Versions
- There are different versions of the HR diagram, some of which use absolute magnitude instead of luminosity, others which use spectral class instead of temperature.
Path through the HR diagram
- Stars similar to our Sun follow the path as shown on the diagram.
- The Sun is currently at stage 3, on the Main Sequence.
Path through the HR diagram 2
- After this, at stage 4, it will be a red giant star.
- Finally, at stage 5, it will become a white dwarf.
- Prior to stage 3, the Sun was a protostar (stage 1) and then a T-Tauri star in its infancy at stage 2.
Test yourself on Hertzsprung-Russell Diagrams
The sun started off as what type of star?
The sun is currently which type of star?