The Hertzsprung Russell (HR) diagram is a great way to show the range of stars in the stellar family. It is basically a graph plotting luminosity and temperature for a population of stars.
The diagrams are very helpful in determining the age of star clusters, as the more massive a star is, the shorter its life span. They also show interesting groups of stars, such as low-luminosity hot objects like white dwarfs.
Curriculum connection
Supports senior secondary learning in Earth and Space Science around:
- stellar characteristics
- temperature, colour and luminosity
- interpreting the Hertzsprung–Russell diagram
- stellar evolution
- apparent and absolute brightness/magnitude
- links between stellar properties and position on the H–R diagram
Particularly useful alongside current NCEA Level 2 Earth and Space Science learning about stars and planetary systems.
Learning pathway
The Colour of Stars
Understand how colour reveals temperature.
The Hertzsprung–Russell Diagram (current page)
Learn how temperature and luminosity are used to organise stars.
Life Cycle of Stars
Explore how mass changes the life and fate of a star.
Our Stellar Neighbourhood
Apply these ideas to real stars around the Sun.
Try it out
The HR diagram below shows stars within 250 light-years of us taken from the Hipparcos catalogue. The catalogue was compiled from data collected by the Hipparcos Satellite by the European Space Agency.
Click on the stars to see their temperatures in Kelvin and their luminosities relative to the Sun.
Hertzsprung-Russell Diagram of Stars Within 250 Light Years
Interactive diagram of our neighbour stars in the Hipparchos Catalogue, created by Sam Leske
References
Featured photo – Globular cluster 47 Tucanae, photo taken at Star Safari. Canon Ra + Meade LX 200, 15 seconds, F 1.8, ISO 12800. Photo Hari Mogosanu
