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Stars and stellar evolution
Cepheid Variable Star RS Puppis

RS Puppis


This is a Cepheid variable star shrouded by a nebula's thick, dark clouds of gas and dust. The star brightens and dims over a period of 41.4 days, changing between about 3,000 and 8,400 times the intrinsic brightness of our Sun. This star is one of the brightest known long-period Cepheids in the galaxy.


Found in the Puppis constellation, in the Southern Hemisphere

Distance from Earth

6,500 light-years


About 10 times the mass of the Sun and about 200 times larger than the Sun

The bright star in this image, RS Puppis, is an example of a Cepheid variable. The star rhythmically brightens and dims over a six-week period.

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"Fast Facts: Cepheid Variable Star RS Puppis" is a table that lists the name, description, location, size, and distance of RS Puppis from Earth. An image of the star is included.

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Adaptable, at teacher's discretion
How to use in the classroom

Use this resource as:

A source of information. Read the table to find out about this object.

A mapping activity. Locate the star's associated constellation on a star map.

A large-number recognition activity. Have students look at several Fast Fact tables, including this one. Ask them to place the objects described in the Fast Fact tables in order, starting with the object closest to Earth and ending with the one farthest away.

An inquiry tool. Have students write down questions they would like answered about the image and the information in the Fast Facts table.

An engagement tool. Involve students in a discussion.

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