Picture of the month

Three years after the dramatic outburst of the star V838 Monocerotis, light continues to echo on surrounding dust. This latest image taken in October 2004 by the Hubble Space Telescope complements the previous sequence showing the propagation of the light-flash through the interstellar medium (CERN Courier June 2003 p12). Each time Hubble observes the event, different thin sections of the dust are seen as the pulse of illumination continues to expand away from the star at the speed of light, producing a constantly changing appearance. Image: NASA, ESA and H E Bond (STScI).