Scientists Discover 30-Million-Year-Old Supernova Equalling Detonation Of 100 Million Suns

A giant star exploded 30 million years ago in a galaxy close to the earth. It was discovered by astrophysicists at Southern Methodist University.

Amazingly, before the supernova, which was like the detonation of a 100 million suns, the star had a radius 200 times bigger than the sun. It underwent a blast that radiated material to blow outward at 10,000 kilometers a second.

The light curve and color spectrum of the exploding star showed some information on the birth and death of the supernovae, which has been baffling for years.

"There are so many characteristics we can derive from the early data," said Govinda Dhungana, an SMU physicist and lead author of the study. "This was a big massive star, burning tremendous fuel. When it finally reached a point its core couldn't support the gravitational pull inward, suddenly it collapsed and then exploded."

The Supernova 2013ej was closest to the Earth in recent years, in the spiral galaxy M74 in the constellation Pisces. Although it is closer to the earth compared to alternative blasts, it was remote enough so that light took 30 million years to reach our Earth, where it was captured by telescopes in July 2013.

Dhungana and his team gathered SN 2013ej information from seven ground-based telescopes along with NASA's Swift satellite. They captured its temperature, mass, radius and chemical elements right from the time it appeared in July all the way to more than 450 days later.

The discovery is expected to help scientists under supernovae.

"The core collapse and how it produces the explosion is particularly tricky," said Robert Kehoe, an SMU physics professor who leads the university's astrophysics team. "Part of what makes SN 2013ej so interesting is that astronomers are able to compare a variety of models to better understand what is happening. Using some of this information, we are also able to calculate the distance to this object. This allows us a new type of object with which to study the larger universe, and maybe someday dark energy."

The findings were published in the April 26 issue of The Astrophysical Journal.