Stellar Explosions Can Create The Awesome Beauty Of Light Echoes
In 2002, the Hubble Space telescope watched as the star V838 Monocerotis exploded in a fiery detonation 600,000 times brighter than our sun. Over four years, the telescope kept watching, and it captured something amazing: instead of gradually petering out, the explosion periodically brightened in what's known as a "light echo."
Here's how a light echo works: the light that travels directly from the brightening object is the first light to reach us (and therefore create an image in our telescopes). The clouds of dust and debris around the object reflect some of that light, causing it to take a longer path and arrive later—in the case of V838 Monocerotis, months later. That creates a ring of light, one that expands from the object at a pace that seems faster than the speed of light. This, however, is only an illusion created by the position of the Earth and the dust's parabolic shape. Learn more about the peculiar characteristics of light in the videos below.