Back in October 2017, scientists observed two dense starts merging at a distance of 130 million light-years away. But this spectacular event wasn’t done stunning us. Using radio telescopes, scientists recently discovered that the particles ejected in a narrow jet were moving almost at the speed of light.
These two merging stars are called neutron stars, which are very dense. For example, if you took a teaspoon of it, it would weigh over a billion tons on our planet!
The event was visually observed and the Laser Interferometer Gravitational Observatory (LIGO) and Virgo experiment also caught the gravitational waves it produced.
After they merged, the pair of neutron stars collapsed into a black hole, creating a spinning disk, which in turn produced that cosmic “burp” observed by the astronomers as a short gamma-ray burst. They also observed a cocoon. Astronomer and lead author of the study which was published in Nature, Kunal Mooley (National Radio Astronomy Observatory (NRAO) and Caltech) explains their findings:
“What creates these jets isn’t known. The mechanism is not known, but once it is produced, now we know from this event that it interacts strongly with the surrounding neutron-rich material to produce this so-called cocoon.”
What they wanted to learn was if these jets would destroy the cocoon or not. They found out after using three telescopes (the Karl G. Jansky Very Large Array, the Robert C. Byrd Green Bank Telescope and the National Science Foundation’s Very Long Baseline Array).
“The Physics of What’s Going On”
The radio emission indeed moved after 75 days after the merger. After 230 days, the radiation moved two light years. Initially, the motion appeared to move four times the speed of light, an impossible thing.
Kunal Mooley explained why this discovery is so important to them:
“It tells us a lot more about the physics of what is going on. For example, in a different work, we showed that with this particular measurement we can also calculate the cosmological parameters such as the Hubble Constant. So there’s a lot of physics that can come out of these observations.”
Andre Blair s is the lead editor for Advocator.ca. He holds a B.A. in Psychology from the University of Toronto, and a Master of Science in Public Health (M.S.P.H.) from the School of Public Health, Department of Health Administration, at the University of North Carolina at Chapel Hill. Andre specializes in environmental health, but writes on a variety of issues.