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The Hertzsprung-Russel Diagram

The Hertzsprung-Russell diagram shows how stars are related by temperature and brightness, revealing patterns in how they evolve. This resource helps students explore these relationships using real stellar data through an interactive diagram.

This activity is part of our live SpacewardBound sessions delivered in schools across New Zealand.

Earth & Space Science
Astrophysics
4 minutes + Interactive
Article

These resources are built from real questions asked by over 40,000 students during our visits to 200+ New Zealand schools.

Prior knowledge

Students should understand basic properties of stars, including temperature and brightness, and have some familiarity with how stars can be classified.

Learning outcomes

    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.

    M20 - The Trifid Nebula taken on 5 Sep 2024 with the Slooh Australia telescope by Sam Leske
    M20 – The Trifid Nebula taken on 5 Sep 2024 with the Slooh Australia telescope by Sam Leske

    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

    We take concepts like this and turn them into interactive, hands-on learning experiences students actually understand.

    We’ve worked with 200+ schools and 40,000+ students, helping make complex space science understandable and engaging. We built these resources from the questions we got from the students and teachers. 

    Teach this tomorrow. Or we’ll bring it to your classroom.

    This activity is part of our live SpacewardBound sessions delivered directly in schools. We run it as a full interactive experience using our mobile planetarium and hands-on activities.

    Used by schools across New Zealand

    Visiting schools across New Zealand to deliver curriculum-aligned astronomy and space experiences.

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