612 km per second – one of the fastest space objects in the galaxy
Massive stars do not die silently.
Their deaths are a dazzling event that illuminates a large part of the cosmos – the explosion of a supernova, which ripples star debris into space and forms an elusive cloud. Meanwhile, the star’s nucleus survives and collapses into an ultraviolet object, or a neutron star, or a black hole.
If this explosion happens in some way, the collapsed nucleus could explode in a Milky Way, at a speed that could also erupt from the galaxy altogether and cut into intergalactic space.
One such object was found in the data of the Chandra X-ray Observatory: a pulsating type of neutron star, the same pulsar that travels at a speed of 612 kilometers per second.
It is one of the fastest objects of its kind ever discovered. The fastest known object in Milky Way is not a supernova remnant, but a star that orbits the supermassive black hole Sagittarius A * in the center of our galaxy. At its fastest point in orbit, it develops incredible speeds of up to 24,000 kilometers per second.
“We saw Pulsar’s motion directly in the X-ray range, and we only did so thanks to Chandra’s clear vision,” said C. Long, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.
The discovery was made while observing a supernova remnant called G292.0 + 1.8 about 20,000 light-years away. Previous observations revealed that there was a rapidly moving pulsar hiding there. Long and his colleagues wanted to study this object to find out if it could tell the story of a supernova; For this it was necessary to move it to the center of the object and vice versa.
“We have only a few reliable records of the explosion of supernovae. Therefore, we wanted to test whether G292.0 + 1.8c would be added to this group, “said astrophysicist Daniel Patnod.
Examined photos taken in 2006 and 2016 for the supernova remnant; They also used Gaia data on its current state in the Milky Way and compared the differences in pulsar positions. The comparisons revealed something extremely interesting: a dead star is moving 30 percent faster than previous estimates indicated.
This means that it took much less time for Supernova to emerge from the waste center, which in turn indicates that Supernova herself must have happened much more recently. According to previous estimates, the supernova explosion must have occurred about 3,000 years ago; New estimates show that in fact, the event took place about 2000 years ago and must have been so dazzling that it would likely have appeared on Earth as well.
Modified pulsar velocity data also allowed the group to conduct new, detailed research into how a dead star could be ejected from the supernova center. Two scenarios were adopted, both of which have a similar mechanism.
An asymmetric explosion can cause a collapsed nucleus of a dead star to explode into space at extremely high speeds; In this case, the star is moving at a higher speed than the middle plate of a Milky Way (550 km / s), but it will take a long time to get there and may even slow down over time. In fact, its speed can be more than 612 km / s.
“This pulsar is about 200 million times more energetic than the earth moving around the sun. “It simply came to our notice then that the supernova explosion was asymmetric,” said astrophysicist Paul Plucinsky.
The group presented the study at the 240th meeting of the American Astronomical Society, already accepted for publication by The Astrophysical Journal, and before that it is available on the arXiv server.