Hubble Space Telescope spots ‘Kilonova’ flash so bright, scientists can barely explain it

According to, the Hubble Space Telescope has caught an explosive flash of two dense Neutron stars, colliding to form a strange supermagnetic star known as a Magnetar. Neutron stars are the superdense remains of a collapsed star, and the bright afterglow of two of these objects is called a kilonova.

The first sign of the explosive event was a gamma-ray burst that occurred on May 22nd, prompting astronomers to prepare their instruments. Scientists believe that gamma-ray bursts usually occur from the collision of two neutron stars, so this seldom seen event brought a lot of observations. As the data came in, researchers realized something strange had occurred: The flash included far more infrared light than expected, ten times the amount.

“The Hubble observations were designed to search for infrared emission that results from the creation of heavy elements, like gold, platinum, and uranium, during a neutron star collision,” Edo Berger, an astronomer at the Center for Astronomy jointly run by Harvard University and the Smithsonian Institution and co-author on the new research, said in the statement.

“Surprisingly, we found much brighter infrared emission than we ever expected, suggesting that there was additional energy input from a magnetar that was the remnant of the merger,” Berger added. “The fact that we see this infrared emission, and that it is so bright shows that short gamma-ray bursts indeed form from neutron star collisions, but surprisingly the aftermath of the collision may not be a black hole but rather likely a magnetar.”

“We know that magnetars exist because we see them in our galaxy,” said Wen-fai Fong, an astronomer at Northwestern University in Illinois and lead author on the new research. “We think most of them are formed in the explosive deaths of massive stars, leaving these highly magnetized neutron stars behind. However, it is possible that a small fraction form in neutron star mergers. We have never seen evidence of that before, let alone in infrared light, making this discovery special.”

“Amazingly, Hubble was able to take an image only three days after the burst,” Fong said. “You need another observation to prove that there is a fading counterpart associated with the merger, as opposed to a static source. When Hubble looked again at 16 days and 55 days, we knew we had not only nabbed the fading source but that we had also discovered something very unusual.”




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