RS Puppis is classed as a Cepheid variable star. It is one of the brightest Cepheid’s and is 10 times more massive than our sun and 200 times the size. It shines at a brightness 15,000 times more than that of our sun.
The star brightens and dims over a six week cycle.
What is unusual is the star is surrounded by thick dark clouds of dust allowing what is referred to as a light echo to be shown. The nebula around RS Puppis is effectively a reflection nebula the brightness of which varies as RS Puppis pulses light outwards.
Imaged in LRGB on my Planewave CDK 1000 at Observatorio El Sauce, Chile.
Image acquisition and processing: Mike Selby