An international team of scientists has discovered a massive new star system which challenges existing theories about the life and death of large stars. The system has been dubbed Apep.
More specifically, scientists have discovered a gamma-ray burst progenitor system. This is a type of supernova that blasts out powerful and narrow jets of plasma, a phenomenon thought to only occur in distant galaxies.
“This system is likely the first of its kind ever discovered in our own galaxy,” says Benjamin Pope, a NASA Sagan fellow at New York University’s Center for Cosmology and Particle Physics and one of the researchers. “It was not expected such a system would be found in our galaxy — only in younger galaxies much further away,” he adds.
Scientists from the Netherlands Institute for Radio Astronomy, the University of Sydney, the University of Edinburgh, the University of Sheffield, and the University of New South Wales were also involved in the study.
It is estimated that the system is located 8,000 light years from Earth. It also seems to be adorned with a slow moving dust ‘pinwheel’. The slow motion of this pinwheel suggests that current theories on star death may be lacking, because it moves slower than system’s solar winds.
When massive stars are nearing the end of their lives, they produce fast winds that typically move at over 1,000 kilometers per second. These strip the star of significant quantities of mass, and should also neutralize its rotational energy, slowing it down long before it dies.
“These massive stars are often found with a partner, in which the fast winds from the dying star can collide with its companion to produce a shock that emits at X-ray and radio frequencies and produces exotic dust patterns,” explains Joseph Callingham, a postdoctoral fellow at the Netherlands Institute for Radio Astronomy.
“Apep’s dust pinwheel moves much slower than the wind in the system,” he adds. “One way this can occur is if one of the massive stars is rotating so quickly that it is nearly tearing itself apart. Such a rotation means that when it runs out of fuel and begins to explode as a supernova, it will collapse at the poles before the equator, producing a gamma-ray burst.”