RS Pup, a pulsating long-period Cepheid embedded in a dusty circumstellar material. The visible light echoes reflect the periodic brightness variation of the star in the middle. This picture taken with the HST also visualizes the usefulness of pulsating variable stars for determining the cosmic distance scale via the period-luminosity relationship.
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/Europe Collaboration. Acknowledgement: H. Bond (STScI and Pennsylvania State University).