Neutron Stars Collide

On August 17, 2017, 4,000 astronomers witnessed the collision of two neutron stars. Neutron stars are about the size of a major city and come from the remains of a supernovae. They are dense and normally have a mass between 1.4-5 times greater than the Sun. For hundreds of millions of years, the two stars orbited each other. Then, eventually, they collided 130 million light years away from Earth.

In August, before the collision, LIGO and Virgo detectors detected gravitational waves along with a gamma-ray burst. Gamma-ray bursts are extremely energetic explosions that are in remote galaxies. In 2017, Rainer Weiss, Barry C. Barish, and Kip S. Thorne won the Nobel prize in physics.

Once alerted of the gravitational waves, many observatories tried to find and observe the two stars. Scientist across the world saw the explosion. It was a bright blue, and then it faded into a red. The event of the collision is called a kilonova. The collision of the neutron stars caused gold and platinum to be scattered all across space. The collision made ten Earths’ worth of gold. Although it is not confirmed yet, many scientists and astronomers believe that the collision produced a black hole. A black hole is “a celestial object that has a gravitational field so strong that light cannot escape it and that is believed to be created especially in the collapse of a very massive star”- Merriam Webster Dictionary. If the stars did create a black hole, it would be the lightest black hole known by humans.

Elements heavier than iron cannot be formed naturally in nature. Half of the universe’s heavy elements are made by star collisions. The metals made from the explosion scatters among the gas in the universe and eventually settles down. The metals condense and forms stars and discs around other stars. Then they form planets that contain some of the metals settled. Earth has gold and other metals because it settled and condensed when the planet was formed.