Here's multiple images of V838 Monocerotis. You can see the change in the light echo over the intervening months.
V838 Mon is not the only example. See below for the light echoes from Supernova 1987A.
Top left is NE. Image width is about 5.5 arc min
Image and text © 1989-2002, Anglo-Australian Observatory, photograph by David Malin.
When supernova 1987A was seen to explode in the Large Magellanic Cloud, the Milky Way's nearest companion galaxy, the brilliant flash of light from the self-destructing star had taken about 170,000 years to arrive. Some light was deflected by two sheets of dust near the supernova, and is seen after the star has faded away because it covers a longer path to reach us. The dust responsible for the rings seen here lies in two distinct sheets, about 470 and 1300 light years from the supernova. The colour picture, made by subtracting images on plates taken before and after the supernova, is an accurate reproduction of the colour of the extremely faint light echo, which in turn reflects the yellow colour of the supernova when it was at its brightest, in May, 1987.
