V838 Monocerotis generated a flash so brilliant that scientists had never seen anything like it before. NASA has just released an image created using data from the Hubble Space Telescope that shows V838 expelling material into space. However, "what we are actually seeing is an outwardly moving 'light echo' of the bright flash - about a million times solar luminosity - from 11 years ago." Continue reading for a video and more information.
According to NASA: "A light echo, light from the flash, is reflected by successively more distant rings in the complex array of ambient interstellar dust that already surrounded the star. It is still not known what caused the flare, but theories include an eruption caused by helium eruptions as the star entered its death throes, the swallowing of planets by V838 or that V838 is a very massive supergiant that underwent a thermonuclear event. The expansion took only a couple of months, meaning that its speed was abnormal."