The New Astronomy: Viewing the Cosmos through Light and Gravity

Astronomers from all over the world learned about a spectacular collision of two stars in the distant past on a summer day in 2017. A group of astronomers from the Virgo and LIGO observatories transmitted the communication. In comparison to the telescopes we have used in the past to investigate the universe, these new observatories are considerably different. The gravitational wave observatories LIGO and Virgo watch out for subtle alterations in spacetime brought on by far-off black holes and neutron stars colliding. Astronomers identified the signal from the collision of two neutron stars, known as GW170817 that LIGO and Virgo discovered on August 17, 2017. A gamma-ray burst signal was picked up by NASA's Fermi satellite less than two seconds later, and within minutes, telescopes all around the world were scanning the sky. South American telescopes discovered the collision site in the far-off galaxy NGC 4993. Astronomers observed the galaxy and the waning light from the collision for the following weeks and months. This is a novel use of multi-messenger astronomy in which gravitational waves and light simultaneously observed the same event.