One of the most violent explosions in nature - the supernova - will be the topic of a live astronomy show at CU-Boulder's Fiske Planetarium on Friday, Oct. 12, and Tuesday, Oct. 16, at 7:30 p.m.
CU-Boulder astronomy Professor Richard McCray will talk about why stars become supernovae and how scientists have learned about this fundamental process of nature, as well as the human perspective on the phenomenon.
During a supernova explosion, a star's brightness can suddenly increase by more than a million times. It is in these tremendous fireballs that all the elements heavier than iron, comprising everything from the planets to human beings, are produced, he said.
The spectacular explosions have been witnessed since before the dawn of written history, according to McCray. "It's probable that our ancestors within the past 100,000 years may have witnessed a nearby supernova brighter than the full moon, and lasting for more than a year," he said.
Bones and tortoise shells from China with 3,500-year-old inscriptions describe events in the sky that may have been supernovae, he said.
"Today, the study of supernovae is one of the most active fields of astronomical research," said McCray. "We observe hundreds each year, with telescopes on the ground and in space, and we are still learning a great deal about these explosions and their consequences."
Supernovae are one of the key processes of nature and, according to McCray, they are important subjects for research not only because they create the heavy elements, but also because they play a big role in star formation.
Because supernovae can be seen at very great distances, they act as signposts to the distant universe. "They're the best way we can measure the speed of expansion of the universe," McCray said. "In fact, in the past two or three years they've been used to find evidence that the universe is speeding up."
McCray became interested in supernovae in the 1960s while he was a graduate student. Then in 1987, the brightest supernova in nearly 400 years was discovered. "I immediately began trying to interpret this event and it has remained the primary focus of my research program ever since," he said.
Tickets go on sale at 7 p.m. the night of the show and are $4 for adults and $3 for children and seniors. Following McCray's talk, the observing deck of the Sommers-Bausch Observatory will be open for free telescope viewing.
For more information contact Fiske Planetarium at (303) 492-5001 or visit the Website at .