When astronomers around the world watched the epic collision between two neutron stars in 2017, the main event was just the beginning. After effects, both immediately And the The long-termfor such a massive, unprecedented fusion was bound to be exciting, intriguing, and informative.
Now scientists have uncovered Doozy. When the two neutron stars collided with each other, they ejected a jet of material that, to our eyes, appeared to be exploding through space at seven times the speed of light.
This, of course, is impossible, according to our current understanding of physics. It is a phenomenon known as hypervelocity, which despite its name is actually an illusion based on our viewing angle.
However, even after correcting its speed, the plane was found to be very fast.
“Our result indicates that the aircraft was moving at least 99.97 percent of the speed of light when launched.” Says the astronomer Wenbin Lu from the University of California, Berkeley.
The data on the plane was acquired by the Hubble Space Telescope, which took a set of observations in about 8 days and then again about 159 days after the merger, Seen here on earth in August 2017.
Other telescopes were watching, including the European Space Agency’s Gaia satellite and a number of radio telescopes from the National Science Foundation. By pooling their data, researchers can create a type of measurement called very long fundamental interferometry (VLBI).
Based on these observations and months of analysis, a team led by astronomer Kunal Muli of the California Institute of Technology was able to first identify the motion of a jet and then track it as the ultra-intense stellar cores came together.
Hyperluminous motion occurs when something comes towards us at a high enough speed, very close to our line of sight. As the object gets closer, the distance required to transmit the light to us decreases – something we don’t usually need to take into account in our daily lives, since the light appears to be moving instantly (compared to our slow motions).
In this case, the plane is moving at roughly the same speed as the light it is emitting, creating the illusion of its light appearing to cover longer distances than it is (and therefore moving at an impossible speed).
Revealing an aircraft’s true speed requires accurate data, and a lot of stress on numbers.
Hubble data showed the ultra-fast speed of light seven times faster than light. VLBI data were acquired between 75 and 230 days after fusion and covered in a previous papershowed that the plane subsequently slowed down to a superfast speed four times faster than light.
“I am amazed that Hubble can give us such a precise measurement, which rivals the accuracy achieved by the powerful VLBI radio telescopes scattered around the world,” Molly says.
The result restricts the angle from which we view the aircraft and strengthens the connection between them neutron star Mergers and short-lived gamma-ray bursts. This connection requires a relativistic jet, which is exactly what Molly and colleagues have measured.
“In this work we have shown that accurate astronomical measurement using space and infrared telescopes is an excellent way to measure the appropriate motions of jets in neutron star mergers,” They write on their papers.
“The James Webb Space Telescope (JWST) should be able to perform astrometry much better than that with the Hubble Space Telescope, due to the larger assembly area and smaller pixel size… the combination of optical astrometry and radio VLBI measurements (with existing observing facilities) It may be more powerful, and could impose strong constraints on the viewing angles of neutron star mergers located 150 million pieces away. [roughly 500 million light-years]. “
Now, we just have to wait for another neutron star to collide…
The team’s research was published in temper nature.