(ORDO NEWS) — When massive stars die, they don’t do it quietly.
Their deaths are impressive glittering events that light up the cosmos, a supernova explosion that blasts star guts into space in a cloud of splendor. Meanwhile, the core of the star-that-was may be left behind, shrinking into a superdense neutron star or black hole.
If this explosion happens in a certain way, it can send the collapsing core hurtling through the Milky Way like a bat out of hell, at such insane speeds they could eventually fly clean out of the galaxy, making a wild journey into intergalactic space.
It’s one of those objects that were new measurements based on data from the Chandra X-ray Observatory: A type of pulsating neutron star known as a pulsar is tearing apart its own insides at about 612 kilometers per second (or 1.4 million miles per hour).
It is one of the fastest objects of its type ever discovered. (The fastest known star in the Milky Way is not a supernova remnant hit by an explosion, but a star orbiting Sgr A*, the supermassive black hole at the center of the galaxy. At its fastest point in its orbit, it travels at a wild 24,000 kilometers per second .)
“We directly saw the movement of the pulsar in X-rays, which we could only do with Chandra’s very sharp eyesight,” said astrophysicist Xi Long of the Harvard and Smithsonian Center. for Astrophysics (CfA).
“Because it’s so far away, we had to measure the equivalent of a quarter’s width at about 15 miles away to see this movement.”
The detection was made by observing a glowing supernova remnant about 20,000 light-years away, named G292.0+1.8. Previous observations have revealed a moving pulsar in it. Long and his colleagues wanted to study the object to see if it could reveal the history of the supernova by tracing it back to the center of the object.
“We only have a few supernova explosions. which also have reliable historical records associated with them,” said astrophysicist Daniel Putnod of CfA, “so we wanted to see if G292.0+1.8 could be added to this group.”
They studied the images. took a picture of the supernova remnant in 2006 and 2016, and used Gaia data on its current location in the Milky Way, comparing differences in the position of the pulsar.
These comparisons revealed something extremely interesting: the dead star appears to be moving 30 percent faster than previous estimates suggested.
This means it took much less time to get from the center of the supernova remnant, suggesting the supernova itself happened much later. Previous estimates placed the date of the supernova explosion at about 3,000 years ago; according to new estimates, this happened about 2000 years ago.
The revised speed of the pulsar also allowed the team to conduct a detailed new study of how a dead star could have been ejected from the center of a supernova. . They came up with two scenarios, both of which involve a similar mechanism.
In the first case, neutrinos are ejected asymmetrically during a supernova explosion. In another case, the debris from the explosion is ejected asymmetrically. However, since the energy of the neutrino must be extremely large, an asymmetric fragment is a more likely explanation.
Essentially, an unequal explosion can “throw” the collapsed core of a dead star into space at an extremely high frequency. speed; in this case, the star is currently moving faster than the Milky Way’s average disk escape velocity of 550 kilometers per second, although it will take quite a while to reach and may slow down over time.
In fact, its true speed may even be higher than 612 kilometers per second, because it moves very little along our line of sight.
“This pulsar is about 200 million times more energetic than the Earth’s motion around the Sun,” said astrophysicist Paul Pluczynski of CfA. “It looks like it got a massive push just because the supernova explosion was asymmetric.”
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