Do I need to install anything?

No. It runs in any modern browser, free, with no account required.

For Engineers · H-R Diagram

H-R Diagram for a star cluster

Built for engineers using it for real design work. Go from concept to a running model in the browser, then scale to the cloud when needed. Simulate a star cluster live below — adjust the inputs and watch it respond, right in your browser.

Hertzsprung-Russell DiagramLive

the map of the stars

Controls

Presets

Your star temperature (K)

The H-R diagram plots stars by temperature and luminosity, revealing the main sequence (a diagonal band), red giants, supergiants, and white dwarfs. Your star (pink ring) sits on the main sequence where luminosity scales as T⁴.

▶ Run in Python

Data Inspector

Spectral classG

Luminosity1.00 L☉

Temperature5,778 K

Governing equation

\frac{L}{L _{⊙}} = (\frac{T}{T _{⊙}})^{4} = (\frac{5778}{5778})^{4} = 1.00

Reading this result: A cool orange K-type star: lower temperature places it low-right on the main sequence, dimmer and longer-lived than the Sun.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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More with H-R Diagram

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Frequently asked questions

Is this good for engineers?: Yes — this version of "H-R Diagram for a star cluster" is framed for engineers using it for real design work. Go from concept to a running model in the browser, then scale to the cloud when needed.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.