Astronomers have discovered a record number gravitational waves. This discovery will help them to understand the origins of the universe and the fate of stars.
A global team of scientists has made 35 additional observations of gravitational wave activity, bringing the total number of detections to 90 since 2015.
Gravitational waves can be described as ripples in spacetime caused by large cosmic events like the smashing of pairs of black holes, which are billions of light-years away.
These waves were detected by the Laser Interferometer- Gravitational Wave Observatory (Ligo), an observatory in the USA, and the Virgo instrument from Italy between November 2019 & March 2020.
In 2016, the first detection of gravitational wave was made. This confirmed an earlier prediction that Albert Einstein had made 100 years ago, based on his general theory about relativity.
Shanika Galaudage from Monash University, a Monash University researcher, describes gravitational waves, which she described as a revolutionary new window into the universe.
Galaudage stated that gravititational waves do not emit [electromagnetic] light. It is possible to see invisible things, such binary black hole mergers.
32 of the 35 new discoveries were likely due to black hole merging.
Two massive black holes that orbit each other were among the most notable discoveries. One pair was 145 times heavier than the mass of our sun and the other 112 twice. Scientists also found a pair of light black holes that had a combined mass of only 18 times the sun.
Two of the 35 detections were believed to be caused by a neutron star merging into a black hole.
The neutron stars are tiny, dense objects that weigh about 1.4 times as much as the sun. However, they can be city-sized with a radius of around 15km. This is according to Prof Susan Scott of the Australian National University.
Scott stated that the detections are helping scientists understand the evolution of the universe as well as the nature of starlight objects.
Scott stated that the number of detections made recently was tenfold higher than when the Ligo-Virgo instruments began observing gravitational waves. Scott attributed the rise to improvements in the instruments that detect gravitational waves, including an increase in laser power.
Scott stated that eventually, as the detectors become more sensitive, we will be able see all binary black hole pairs joining together in the entire universe.
Because they aren't as dense as black holes, they don't create strong gravitational waves when they collide. Therefore we can't see them as far.
Astronomers might be able to detect gravitational wave from stars when they become supernovae in the future. Scott stated that this would allow us to better understand star's collapse after they have completed their lifecycle and run out fuel.
Galaudage stated that scientists were able to identify the origin of mergers by analysing their properties.
Looking at the speed at which a black hole spins, or how its pointed, can reveal more about its origin. This includes whether it was separated in their lives, or whether they were stars.
Some of these new discoveries are still unknown. Researchers believe that the 35th event could either be a pair or merger of two black holes.
This lighter object had a mass that was larger than the usual neutron star, but smaller as a black hole. Galaudage stated that they were seeing features we don't understand yet.