V838 Monocerotis Movie
This is a short (17 seconds, 4.9 MB) QuickTime movie of the unusual brightening of the star V838 Monocerotis.
In 2002 a rare, inexplicable event occurred. A star increased its brightness by a factor of 600,000.
The light from this event propogated outward, illuminating the surrounding dust and gas.
This reflected light is called a 'light echo' and is what we are seeing in the above video.
The bright red star is the responsible party, although we now know that V838 is a double, or binary, star system where two stars orbit each other.
This outburst was not a star 'going nova', which is a nuclear fusion explosion which expels a stars outer layers.
Instead, V838 grew enormously in size until its surface temperature was not much hotter than a light bulb!
The surrounding dust and gas were theorized at one time to have been blown off of V838 in previous episodes, but recent Spitzer images in the infrared seem to indicate much more material than could have come from the star.
V838 is about 20,000 light years away from us.
The first light eruption occurred at shorter wavelengths, which is why the outer border of the light echo is bluish.
What could have caused this cataclysmic brightening and ballooning in size?
Theories abound, but two of the strong possibilities are the merger of the binary stars or one of the stars swallowing some of its giant planets.
The four source images for this animation are seen below.
The intervening movie frames were made by morphing one image into the next. As such, this movie is more fanciful than strictly scientific.