Researchers observed a "monster" gamma-ray burst.
These bursts of gamma-radiation come from exploding massive stars, and researchers noticed a particularly large event in region relatively close to our solar system, a University of Copenhagen news release reported.
In these events the star is not visible because it is too dim to see from Earth, but when it does explode the supernova can be observed. When the star explodes it often emits a "violent burst of radiation." These gamma-ray bursts are believed to be so bright that they can be seen throughout the universe; the rays are observed by Earth's atmosphere so cannot be spotted from the blue planet's surface.
In order to observe these rays researchers turned to telescopes outside of Earth's atmosphere, in this case they observed the gamma-ray burst "monster" using the Swift satellite.
"We suddenly saw a gamma-ray burst that was extremely bright -- a monster gamma-ray burst. This one of the most powerful gamma-ray bursts we have ever observed with the Swift satellite," astrophysicist Daniele Malesani, of the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen, said.
As soon as Swift detects the gamma-ray burst it uses instruments to measure the "X-rays, ultraviolet radiation and optical light" created in the visible range.
"We follow the so-called afterglow, which usually lasts a few days or for several weeks, from both Swift and from the ground-based telescopes. In this case, the burst was so powerful that we could observe the afterglow for several months. By analysing the light from the afterglow, we can study its spectral composition, which can tell us about the properties of the original star. What we have discovered is that it is a giant star with a mass that is 20-30 times the mass of the Sun, and rapidly rotatng. But its size is only [three to four] times that of the Sun, so it is extremely compact. These kinds of stars are called Wolf-Rayet stars," Malesani said.
The researchers believe the star exploded when the universe was 9.9 billion years old, and took 3.75 billion years to reach the Milky Way.
