A Bunch of Undergrads Discovered a Supernova, and You Can See It Too

M82 is already a popular galaxy for beginner skywatchers, given its luminosity. Image: NASA

A long time ago (12 million years) in a galaxy far away (Messier 82), a star exploded. On January 21st at 7:20 PM GMT, it was spotted by a bunch of undergraduate students during a 10-minute telescope workshop at the University College of London.

“One minute we’re eating pizza then five minutes later we’ve helped to discover a supernova,” said student Tom Wright, in a press release on UCL's site. “I couldn’t believe it. It reminds me why I got interested in astronomy in the first place.” Yet more proof that pizza is a precursor of great things.

An image of the new supernova. Image: UCL/University of London Observatory/Steve Fossey/Ben Cooke/Guy Pollack/Matthew Wilde/Thomas Wright

After a global scramble to confirm the observation, the flash of light from our neighboring galaxy has been verified as a supernova. Astronomers are thrilled, and rightly so. “PSN J09554214+6940260,” as the supernova is currently known, is one of the nearest and brightest stellar explosions for almost three decades, when SN 1987A lit up the skies.

On top of that, it has been caught two weeks before it hits peak brightness, so astronomers have plenty of time to prepare to observe its majestic ejection of star guts. It may even become luminous enough to view through binoculars. Plus, it should be easy to find even for amateur stargazers, because M82 is tucked into one of the most recognizable constellations in the Northern Hemisphere: Ursa Major. Sky and Telescope has some great tips for anyone interested in tracking down the supernova.

The news actually gets better: Spectral analysis of the explosion revealed that the star ejected large amounts of heavy elements like silicon, but relatively little hydrogen. This means it's a Type 1a supernova: the death of a white dwarf. These events are rare, especially in a starburst galaxy like M82, where most supernovae occur when young, massive stars undergo core collapse.

As Phil Plait explained yesterday in Slate, Type 1a supernovae still have a shroud of mystery surrounding them. He outlined three main theories about how these explosions go down, all of which involve multi-star systems. For example, a white dwarf could be skimming gassy matter off of a larger star it orbits. The material would build up like a pressure-cooker until the white dwarf undergoes a thermonuclear explosion.

The supernova could also be the result of two white dwarves orbiting each other until they collide, or even a “three's a crowd” situation in which the gravity of a larger star smashes two white dwarves together. Whichever theory is correct—and perhaps all three are—this new supernova is sure to shed light on the subject.

Type 1a supernovae also present another awesome opportunity: the measurement of cosmic distances. When white dwarves call it quits, they exhibit about the same luminosity no matter where they are in the universe. The more we know about the causes and behavior of these explosions, the more we'll be able to track them down in other galaxies. That means better intel on the geometry of the universe as a whole. Not too shabby for a tiny senior star.

Of course, no supernova discussion is complete without a reference to lookback time. The light from M82 is 12 million old, meaning this white dwarf died when megalodons roamed the oceans, forests flourished in Antarctica, and the ancestors of humans had just cleaved themselves from those of orangutans. What's breaking news for us is ancient history for the remains of Messier 82's long-lived white dwarf. So rest in pieces, old-timer, and thanks for going out with a bang.