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Star Classification Generator

Used by developers, writers, and creators worldwide.

A star classification generator presents a fact card on a real stellar spectral class — the O, B, A, F, G, K, M sequence astronomers use — with its true temperature range, colour, example stars, and a note. Astronomy teachers, students, and quiz-makers need accurate class summaries, and the order is famously easy to forget. This tool draws a complete, internally consistent card so the temperature, colour, and example stars always belong to the class shown. Click to draw a class and copy the card. It is ideal for teaching stellar classification, building revision flashcards, writing astronomy questions, and labelling stars in a project. Because each card keeps its own facts together, you can trust the temperature and examples and drop them straight into lessons, notes, or a star chart.

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How to use

  1. Choose your options above
  2. Click Generate
  3. Copy your result

Detailed instructions

  1. Click Generate to draw a class.
  2. Read the temperature and colour.
  3. Note the example stars.
  4. Copy the card or draw again.

Use Cases

  • •Teaching stellar classification
  • •Astronomy revision flashcards
  • •Writing astronomy quiz questions
  • •Labelling stars in a project
  • •Comparing star temperatures

Tips

  • →Remember the order O B A F G K M.
  • →Compare hot and cool classes.
  • →Draw again for another class.
  • →Pair with an HR diagram.

FAQ

what does the spectral class mean

The class, from O to M, orders stars by surface temperature and colour — O is hottest and blue, M is coolest and red. Each card shows the real temperature range, colour, and example stars for one class.

is the data accurate

Yes. Each class is stored with its own true temperature range, colour, and well-known example stars, and the card is drawn as a whole. The details always match the class named.

which class is the sun

The Sun is a G-type star, with a surface temperature around 5,800 K and a yellow colour. G-type stars sit in the middle of the sequence, which is one reason the card highlights the Sun as an example.