Northwestern astronomers detect possible kilonova

A team of Northwestern researchers may have identified an afterglow from a kilonova — a cosmic event that only happens when two neutron stars collide. The merger event in question, named GW170817, occurred three and a half years ago. The resulting measurement from this collision could mean the astronomers at Northwestern are the first scientists to ever record such a discovery from a kilonova.

The study that led to the groundbreaking encounter was piloted by Aprajita Hajela, a graduate student in the Department of Physics and Astronomy at Northwestern and the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). Also included in the project is co-author and CIERA post-doctoral fellow Kate Alexander. Hajela and her team had been monitoring the X-rays using NASA’s Chandra X-ray Observatory when they realized brightness from the emissions stayed consistent.

“We have entered uncharted territory here in studying the aftermath of a neutron star merger,” said Hajela. “We are looking at something new and extraordinary for the very first time. This gives us an opportunity to study and understand new physical processes, which have not before been observed.”

“Further study of GW170817 could have far-reaching implications,” said Alexander. “The detection of a kilonova afterglow would imply that the merger did not immediately produce a black hole. Alternatively, this object may offer astronomers a chance to study how matter falls onto a black hole a few years after its birth.”

Read more in Northwestern Now’s new article, “Kilonova afterglow potentially spotted for first time.”