#NASA's #Hubble Sees Unexplained #Brightness from #Colossal #Explosion

Issued by Inbox Astronomy 

In our infinite universe, stars can go bump in the night. When this happens between a pair of burned-out, crushed stars called neutron stars, the resulting fireworks show, called a kilonova, is beyond comprehension. The energy unleashed by the collision briefly glows 100 million times brighter than our Sun.

What's left from the smashup? Typically an even more crushed object called a black hole. But in this case Hubble found forensic clues to something even stranger happening after the head-on collision.

The intense flood of gamma-rays signaling astronomers to this event has been seen before in other stellar smashups. But something unexpected popped up in Hubble's near-infrared vision. Though a gusher of radiation from the aftermath of the explosion—stretching from X-rays to radio waves—seemed typical, the outpouring of infrared radiation was not. It was 10 times brighter than predicted for kilonovae. Without Hubble, the gamma-ray burst would have appeared like many others, and scientists would not have known about the bizarre infrared component.

The most plausible explanation is that the colliding neutron stars merged to form a more massive neutron star. It's like smashing two Volkswagen Beetles together and getting a limousine. This new beast sprouted a powerful magnetic field, making it a unique class of object called a magnetar. The magnetar deposited energy into the ejected material, causing it to glow even more brightly in infrared light than predicted. (If a magnetar flew within 100,000 miles of Earth, its intense magnetic field would erase the data on every credit card on our planet!)