[ad_1]
These three panels reveal a supernova before, during and after its event, 920 million light years from Earth (from left to right). Photo courtesy of NASA.
When the stars explode, they usually go out with a bang rather than moaning. Scientists therefore knew that they had come across something unusual when they had seen a huge star die quietly at 920 million light years from Earth.
The observations of scientists from the California Institute of Technology and the Carnegie Science Institute were published in Science on Thursday.
Although the star was on the periphery of a spiral galaxy distant several million light years away, the event itself was captured by the Palomar Observatory. , who performs a night study of the sky in search of supernovae.
Mansi Kasliwal, assistant professor of astronomy at Caltech, and graduate student Kishalay De observed the star's faint supernova, which quickly faded. Although the star represents at least eight times the mass of our sun, it ejected only one fifth of the mass of the sun during the explosion.
As a rule, the nucleus would collapse inwards before exploding outward in a powerful and violent explosion.
"We have witnessed the collapse of the nucleus of this massive star, but we have seen a mass mass ejected remarkably low," Kasliwal said in a statement. "We call this a supernova of ultra-stripped envelope and have long predicted their existence. This is the first time we have convincingly seen the collapse of the nucleus of such a massive star that has no material left. "
For the star to explode in the first place, it had to contain a lot of material – otherwise, it would not have collapsed. So the scientists started to investigate the mystery of the missing mass.
The researchers realized that this huge star was not the only one and that a companion star – invisible to them – was using gravity to siphon the mass of the star before it exploded.
Now, what remains of the once massive star is a dense neutron star. These complex stars have only the size of a small town, but they are so dense that they contain more mass than the sun. To put this into perspective, a teaspoonful of neutron star would weigh as much as a mountain, the researchers said.
The companion of the star is also a compact and dense neutron star. This is the first time that scientists are witnessing the birth of a compact binary neutron star system.
But things will not end well for these two stars. Finally, because of their proximity, the stars will collide. The event will look a lot like the collision of neutron stars observed by astronomers in August 2017 and that has produced gravitational waves, electromagnetic waves and heavy elements like gold, platinum and silver. # 39; uranium.
40.712775
-74.005973
Source link
