Scientists looking for gravitational waves, ripples in the fabric of space and time radiated by cataclysmic collisions, had an eventful month.
The LIGO and Virgo observatories responsible for detecting these waves started their most recent observation operation on April 1 and have already proposed 5 possible signs of gravity. The observatories are 40% more sensitive due to the updates made since the end of the last observation campaign.
By detecting these gravitational waves on Earth, scientists can work backward to find out more about what caused these ripples, so we can better recognize some of the more extreme objects in the universe.
“The entire astrophysical community is very happy to have participated in five candidate events in four weeks.”
Three gravitational wave signals would come from two black holes combined; the fourth would have been emitted by neutron stars in shock. The fifth and perhaps the most exciting seem to derive from the fusion of a black hole and a neutron star.
If this is confirmed, this is the first black hole-neutron fusion ever documented. The five signs still need to be confirmed by a follow-up analysis.
LIGO and Virgo can detect these gravitational waves; thanks to highly accurate instrumentation. When a gravitational wave passes through the earthly part of space, each atom distorts a bit.
A laser moves the arms of the three L-shaped detectors of LIGO and Virgo. As soon as the laser touches the tip of the detector, a mirror brings the light back to the center.
If no gravitational wave has passed, the light beams must return simultaneously to the curvature of the L, but if there is an imbalance, a gravitational wave may have been observed.
Unlike previous observation campaigns, both observatories began to publish their detections in real time, enabling other observatories to perform constant follow-up.