Neutron-Star Collision Releases Puzzling Burst of Infrared Light

This image shows the glow from a kilonova caused by the merger of two neutron stars.

In May of 2020, light from this flash reached Earth and was first detected by NASA's Neil Gehrels Swift Observatory. Scientists quickly enlisted other telescopes — including the NASA/ESA Hubble Space Telescope — to study the explosion's aftermath and the host galaxy.

Hubble found that the near-infrared emission was 10 times brighter than predicted. These results challenge conventional theories of what happens in the aftermath of a short gamma-ray burst. One possibility is that the observations might point to the birth of a massive, highly magnetized neutron star called a magnetar.

The kilonova, whose peak brightness reaches up to 10,000 times that of a classical nova, appears as a bright spot (indicated by the arrow) to the upper left of the host galaxy. The merger of the neutron stars is believed to have produced a magnetar, which has an extremely powerful magnetic field. The energy from that magnetar brightened the material ejected from the explosion.