On a cold, dark night in February 1987 on top of a south Chilean mountain range, Dr. Ian Shelton stared at the starry sky.
He embraced a moment that no other astronomer had experienced in nearly 400 years — a supernova unfolding before his very eyes.
“I put out the facts to a colleague and he said without hesitation that it was a supernova,” Shelton said. “He looked at me and said, ‘You’re kidding.’”
Shelton, then 30 years old, spent long months at the Los Campanas Observatory. As a student in the University of Toronto’s astronomy department, he was the resident astronomer at the university’s southern observatory, training others to use the telescope and maintaining the large device.
“I thought it would be good for a nova search campaign, just to take images of the same region of the sky every night in a routine manner and then have an army of students or people at local universities go through the plates,” he said.
On Feb. 24, 1987, Shelton was taking three-hour exposures of a section of the sky about the size of two hands side-by-side. High winds forced him to close the observatory roof, ending his work for the night.
Very quickly, he realized there was an extra star on the image.
“I had looked through the telescope to line it up by eye on a star that’s close to the centre of the field,” he said. “(The supernova) was closer to the centre of the field, so I knew that it wasn’t the star I lined it up on.
The significance of the discovery for the international scientific community was big. The ability to watch such a rare event from the beginning, Shelton said, turned what the community understood about astronomy and physics on its head.
It took a few hours to get the news out to other observatories around the world. When the astronomers were unable to reach anyone by radio phone, the message was hand-delivered to the closest village a hundred kilometers away to be sent out by telegram.
Shelton and his colleagues on the mountaintop spent the next three months studying the supernova. But Shelton understood the pressure that was now on him for making one of the biggest discoveries of the decade.
He has since worked at several other observatories: Japan’s 8.3-metre Subaru Telescope in Hawaii, the 1.9-metre David Dunlap Observatory in Toronto and the 6.5-metre MMT Observatory south of Tucson, Ariz. He’s also worked at Athabasca University and as a professor of physics at Mount Allison University in New Brunswick.