Cepheid variable
![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Heic1323a_-1243686232.jpg/400px-Heic1323a_-1243686232.jpg)
RS Puppis is ane o the brichtest kent Cepheid variable starns in the Milky Way galaxy; image, Hubble Space Telescope
A Cepheid variable is a teepe o starn that pulsates radially, varyin in baith diameter an temperatur an producin chynges in brichtness wi a well-defined stable period an amplitude.