Earlier this year, the space community celebrated the 25th anniversary of the Hubble space telescope and the treasure trove of breathtaking images it has provided of our universe.
One of Hubble’s most dramatic discoveries, however, was V838 Monocerotis, a red star about 20,000 light years away from the sun. The unusual star experienced an outburst in early 2002, temporarily increasing in brightness to about a million times that of our sun. It also increased in diameter to about the size of Jupiter’s orbit around the sun.
As the light from the eruption propagated outwards, it lit up the surrounding dust structures before traveling towards Earth, where Hubble snatched it up. This phenomenon, known as a “light echo,” is analogous to the echoes produced by sound waves as they bounce off of various surfaces and back to a listener.
This featured video (shown above), from the YouTube channel “Our Universe Visualized,” features a time-lapse of the light echo following the outburst of V838 Monocerotis in images taken between 2002 and 2006.
Scientists continue to debate the cause of V838 Monocerotis’s magnificent outburst of light. One theory suggests that V838 Monocerotis is actually part of a binary star system, and that the explosion was the result of another star being pulled onto V838 Monocerotis’s surface.
Another more grisly theory is that V838 Monocerotis swallowed up its neighboring planets. Once the planets – perhaps gas giants like Jupiter and Saturn – entered the star’s atmosphere, the star began to expand rapidly. The leading theory, however, is even more violent. Perhaps a low-mass star, smaller even than our relatively small sun, collided and merged with V838 Monocerotis. Such unions are rare, but the result is generally a huge outburst of energy.