This image captures a light echo from the star V838 Monocerotis. After the star brightened temporarily, light from that eruption began propagating outward through a dusty cloud around the star. The light reflects or “echoes” off the dust and then travels to Earth.
V838 Monocerotis is a cataclysmic binary star in the constellation Monoceros about 19,000 light years from the Sun. The previously unremarked star was observed in early 2002 experiencing a major outburst, and was one of the largest known stars for a short period following the outburst.