Carnegie Mellon University
October 15, 2017

Scientists Spot Explosive Counterpart of LIGO/Virgo’s Latest Gravitational Waves

By Andre Salles, Fermilab Office of Communication

Jocelyn Duffy

Today, a team of scientists using the Dark Energy Camera (DECam), the primary observing tool of the Dark Energy Survey, was among the first to observe the fiery aftermath of a recently detected burst of gravitational waves, recording images of the first confirmed explosion from two colliding neutron stars ever seen by astronomers. Their data was bolstered by data captured at other observatories around the world.

"The event is perhaps the grandest demonstration yet that science is an international endeavor, with dozens of telescopes built and operated by thousands of scientists joining forces to confirm that the event was likely an explosion caused by the merger of two neutron stars," said Scott Dodelson, head of Carnegie Mellon’s Department of Physics and co-chair of the Dark Energy Survey’s science committee.

"This event will stand as a remarkable achievement for the astronomical community and opens up the door for even more exciting time-domain astronomy."

Images taken with DECam captured the flaring-up and fading over time of a kilonova "an explosion similar to a supernova, but on a smaller scale" that occurs when collapsed stars called neutron stars crash into each other, creating heavy radioactive elements. This particular violent merger, which occurred 130 million years ago in a galaxy near our own (NGC 4993), is the source of the gravitational waves detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo collaborations on Aug. 17. This is the fifth source of gravitational waves to be detected---the first one was discovered in September 2015, for which three founding members of the LIGO collaboration were awarded the Nobel prize in physics two weeks ago.

This latest event is the first detection of gravitational waves caused by two neutron stars colliding, and thus the first one to have a visible source. The previous gravitational wave detections were traced back to binary black holes, which cannot be seen through telescopes. This neutron star collision occurred relatively close to home, so within a few hours of receiving the notice from LIGO/Virgo, scientists were able to point telescopes in the direction of the event and get a clear picture of the light.

"This event will stand as a remarkable achievement for the astronomical community and opens up the door for even more exciting time-domain astronomy that will emerge during the LSST era," said Fred Gilman, director of Carnegie Mellon’s McWilliams Center for Cosmology. Gilman is the chair of the AURA Management Council for the Large Synoptic Survey Telescope (LSST), a powerful, next generation survey telescope under construction in Chile.



Read more about this discovery:

Carnegie Mellon Department of Physics website

Dark Energy Survey website: