http://www.thestar.com/news/gta/article/1309208--astronomer-looks-back-on-a-star-discovery-of-the-1980s-sn-1987a
Astronomer looks back on a star discovery of the 1980s: SN 1987A
VINCE TALOTTA/TORONTO STAR
Dr. Ian Shelton made perhaps the biggest astronomical discovery of the 1980s: the supernova SN 1987A.
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.
Wanting to make sure he saw what he thought he saw, Shelton went into another observatory on the mountaintop.
“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.’”
SN 1987A — the first supernova discovered since German astronomer Johannes Kepler, said to be the father of modern-day astronomy, observed SN 1604 some 383 years earlier — was born.
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.
“Astronomers coming who scheduled time with the telescope in advance — my job was to show them how to use the telescope and make it do what they needed it to do,” he said.
One perk of the job was free time with the telescope. However, Shelton set his sights on resuscitating a telescope that had been out of service for nearly a decade.
“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.
Ironically, the discovery came on a second night of trial runs to test whether the telescope would do what he wanted it to do.
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.
After he developed the images he placed them on a light tablet to check their quality.
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.
Comparing it to an image from the night before, “it was clear there was a faint star there before and a bright star there that night.”
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.
“This showed we didn’t understand stellar physics as well as we thought we knew,” he said.
From the supernova, physicists discovered tiny particles, called neutrinos, that were emitted during the explosion had reached Earth a few hours before the visible light.
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.
“When I discovered this, I had no credentials,” he said. “I couldn’t contribute past the observational aspect. There was lots of pressure to suddenly deliver and I hadn’t even really started.
“I didn’t want to use this as an excuse for why I was an astronomer. I wanted to prove myself. For my own sanity and respect, I had to make sure I was doing this because I could do it.”
That fall, Shelton entered graduate studies at U of T. He completed a master’s degree in science in 1990 and a doctorate in 1996.
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.
He embraced a moment that no other astronomer had experienced in nearly 400 years — a supernova unfolding before his very eyes.
Wanting to make sure he saw what he thought he saw, Shelton went into another observatory on the mountaintop.
“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.’”
SN 1987A — the first supernova discovered since German astronomer Johannes Kepler, said to be the father of modern-day astronomy, observed SN 1604 some 383 years earlier — was born.
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.
“Astronomers coming who scheduled time with the telescope in advance — my job was to show them how to use the telescope and make it do what they needed it to do,” he said.
One perk of the job was free time with the telescope. However, Shelton set his sights on resuscitating a telescope that had been out of service for nearly a decade.
“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.
Ironically, the discovery came on a second night of trial runs to test whether the telescope would do what he wanted it to do.
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.
After he developed the images he placed them on a light tablet to check their quality.
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.
Comparing it to an image from the night before, “it was clear there was a faint star there before and a bright star there that night.”
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.
“This showed we didn’t understand stellar physics as well as we thought we knew,” he said.
From the supernova, physicists discovered tiny particles, called neutrinos, that were emitted during the explosion had reached Earth a few hours before the visible light.
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.
“When I discovered this, I had no credentials,” he said. “I couldn’t contribute past the observational aspect. There was lots of pressure to suddenly deliver and I hadn’t even really started.
“I didn’t want to use this as an excuse for why I was an astronomer. I wanted to prove myself. For my own sanity and respect, I had to make sure I was doing this because I could do it.”
That fall, Shelton entered graduate studies at U of T. He completed a master’s degree in science in 1990 and a doctorate in 1996.
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.
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