On February 21, 2006 astronomers using the Hubble Space Telescope as part of a Supernova Cosmology Project at Lawrence Berkeley National Laboratory (LBNL) hoping to discover supernovae noticed an odd flash of light. The light increased steadily, becoming brighter, for 100 days, and then became increasingly dim for another 100 days, before disappearing. The image linked in this post shows the same area before the flash, and during the flash.

The steady increase and decrease in brightness doesn't match any known celestial event. The rise and fall in brightness has a signature that simply has never been recorded for any other type of celestial event. Kyle Barbary of LBNL presented a paper regarding the odd flash this week at the American Astronomical Society. Barbary says "We have never seen anything like it."

At the time, Hubble was pointed at a galaxy cluster 8 billion light-years away in the constellation Bootes. The object responsible for the flash might be anywhere between here and there, including the halo around our "local" galaxy, the Milky Way.

Barbary's isn't the first paper written about the odd event. Other astronomers have suggested any number of possible explanations; the collapse and subsequent explosion of a carbon-rich star, or even a collision between a dead "white dwarf" star and an asteroid, or even a white dwarf star and a black hole; all of which is exceedingly speculative, as Barbary notes in saying "I don't think we really know what the discovery means until we can observe similar objects in the future."