Closest supernovae to Earth discovered near Messier 82 galaxy

Students and staff at UCL's teaching observatory, the University of London Observatory, have spotted one of the closest supernovae to Earth in nearby galaxy Messier 82 (the Cigar Galaxy).

The discovery was a fluke-a 10 minute telescope workshop for undergraduate students that led to a global scramble to acquire confirming images and spectra of a supernova in one of the most unusual and interesting of our near-neighbor galaxies.

"The weather was closing in, with increasing cloud, so instead of the planned practical astronomy class, I gave the students an introductory demonstration of how to use the CCD camera on one of the observatory's automated 0.35-meter telescopes," Dr. Steve Fossey said.

The students chose M82, a bright and photogenic galaxy as their target, as it was in one of the shrinking patches of clear sky.

While adjusting the telescope's position, Fossey noticed a 'star' overlaid on the galaxy which he did not recognize from previous observations.

They inspected online archive images of the galaxy, and it became apparent that there was indeed a new star-like object in M82. With clouds closing in, there was hardly time to check: so they switched to taking a rapid series of 1 and 2 minute exposures through different colored filters to check that the object persisted, and to be able to measure its brightness and color.

Meanwhile, they started up a second telescope to obtain a second source of data, to ensure the object was not an instrumental artifact. By about 19:40 GMT, the cloud cover was almost complete, but it was just possible to make out the new object in the second data set: this was a real astronomical source.

There were no online reports of any prior discoveries of this object, so it seemed clear that this was a new transient source, such as a supernova.

The IAU's official report, issued the following day, confirms Fossey as the official discoverer, and gives the supernova the designation SN 2014J.

The supernova is one of the nearest to be observed in recent decades.