The 2017 epic collision between two neutron star stars was only the beginning for astronomers all around the world. Both the after-effects InstantAnd longer-termThe results of such an enormous, unprecedented merger were bound be thrilling, fascinating, and profoundly informative.
Now scientists have discovered a shocking fact. Scientists have now discovered a shocking secret. As the neutron stars collided, a jet of material was ejected that seemed to be blasting into space at seven-times the speed of light.
According to current physics, this is unimaginable. This phenomenon is called superluminal speed and, despite its name, it’s actually an illusion that we created based on our viewing angle.
However, even after its velocity was corrected, it was still insanely fast.
“Our results indicate that the jet was moving at least 99.97% the speed of light at the time it was launched,” Wenbin Lu, an astronomerBerkeley, University of California.
Hubble Space Telescope collected data on the jet and made observations for around 8 days, then again for around 159 days following the merger. Observed here on Earth, August 2017..
Other telescopes were also watching, including the European Space Agency’s Gaia satellite as well as a variety of radio telescopes provided by the National Science Foundation. Researchers were able to combine their data and create a type of measurement known as very long baseline interferometry, or VLBI.
Based on these observations, and months of analysis, a Caltech team led by Kunal Mooley, an astronomer, was able first to identify and then track the movements of a jet that erupted during the collision of two ultradense star cores.
When something is moving at an excessive speed towards us, it can cause superluminal motion. As the object nears, the distance required for its light to travel to us shortens – something we don’t usually need to take into account in our day-to-day lives, where light seems to move instantly (compared with our slow movements).
The jet is moving almost as fast and as fast the light it emits. It creates the illusion of light traveling longer distances than its own, making it appear to be moving at an impossible speed.
It takes precise data and lots of numbers to determine the true speed of the jet.
The Hubble data revealed a superluminal speed seven times faster that light. VLBI data was obtained between 75-230 days after the merger. Covered in a previous paperIt was later shown that the jet could slow down to a superluminal speed, four times faster then light.
“It’s amazing that Hubble could provide such precise measurements. It rivals the precision of powerful radio VLBI telescopes distributed across the globe,” Mooley.
This further limits the angle from which we view the jet, strengthening the link between the two. neutron starMergers and short-duration Gamma-ray Bursts This connection needs a relativistic jet. Mooley and his collaborators have measured it.
“We have shown that precision astrometry using space-based optical, infrared and optical telescopes is a great way to measure jet motions in neutron star mergers,” They write in their paper.
“The James Webb Space Telescope (JWST) should be able to perform astrometry much better than that with the Hubble Space Telescope, owing to the larger collecting area and smaller pixel size… The combination of optical astrometry and radio VLBI measurements (with current observing facilities) may be even more powerful, and could deliver strong constraints on the viewing angles of neutron-star mergers located as far away as 150 Mpc [roughly 500 million light-years].”
Now, we just have to wait for another neutron star collision…
The results of the research by the team have been published in Nature.
