Photo credit: NASA Goddard/ Albert Einstein Institute
What Happens When Neutron Stars Collide?
by Justine Alford
A beautifully elegant visualization of perhaps one of the most ferocious events that can occur in the universe has been released by NASA. This supercomputer simulation, produced by the Albert Einstein Institute, demonstrates what happens when two neutron stars collide and form a black hole.
Neutron stars are one of several possible endings for a star. They form when a huge star, around 8 to 30 times the mass of our Sun, explodes in a supernova. They’re only city size, around 12 miles (20 kilometers) in diameter, but size isn’t everything and they certainly pack a punch with a mass about 1.4 times that of our Sun. To put that into perspective, a cubic centimeter of neutron star matter would weigh more than Mount Everest.
When neutron stars collide a spectacular event ensues. In this simulation, scientists placed a mismatched pair of neutron stars, weighing 1.4 and 1.7 solar masses, 11 miles apart and watched the fateful event play out. As the stars start to whirl toward each other, immense tidal forces warp the crusts of the stars and the smaller star explodes, spewing its hot and dense contents that then begin spiral around the system. As the stars merge, the overwhelming mass acquired by the larger star causes it to collapse, and a black hole is born.
These events are particularly interesting because scientists believe that they may result in short gamma-ray bursts (GRBs). These short GRBs are immense bursts that emit the same amount of energy as all of the stars in our entire galaxy combined produce in a year, in only around 2 seconds. Since these events are over in the blink of an eye observing them in space has proved quite a challenge, but NASA’s Swift mission has been capturing GRB afterglows which has led to a significant increase in our comprehension of these events.