A dissolve sequence of eight images taken by Hubble's Advanced Camera for Surveys shows a CAT-scan-like probe of the three-dimensional structure of the shells of dust surrounding the aging star V838 Monocerotis. The sequence reveals dramatic changes in the way a brilliant flash of light from the star is reflecting off surrounding dusty cloud structures. The effect, called a light echo, has been unveiling never-before-seen dust patterns ever since the star suddenly brightened for several weeks in early 2002.

Credit: NASA, ESA, and G. Bacon

Publication: October 26, 2006