A dance of death is taking place in a distant universe.
There are two black holes locked in an elliptical pattern so tight that they will collide with each other and form a much larger black hole in the blink of an eye.
Around 50 times the average distance between the Sun and Pluto, that equates to an orbital distance of just 0.03 light-years. It takes just two Earth years for the two objects to complete a pair of loops, compared to the long time it takes for the other object.
There are many reasons why black holes are of interest to the astronomer.
When two black holes are found together, it indicates that two other black holes have come together.
We know that this process happens, so finding a black hole can tell us what it looks like in the final stages.
It is possible to tell us something about how these objects can get so massive.
Black hole mergers are one way growth can occur. Finding black holes will help us understand if it is a common pathway for growth, and that could lead to more accurate modeling.
The object in question is a quasar. The supermassive black hole in these galaxies is creating matter at a furious rate, and it is causing heat to come from the material around the nucleus.
Some quasars blast jets of plasma almost at light-speed from the polar regions of the black hole, funneled along and accelerated by magnetic field lines around the object. A blazar is a quasar that blasts out a jet in the direction of Earth.
A team of astronomer noticed something odd about the blazar beam in radio frequencies and collected data back in 2008. It seemed to change in brightness on a regular basis, with an almost perfect sine wave pattern never before seen in a quasar.
astronomer Tony Readhead of Caltech said that there was a pattern that could be traced over time.
There were only two peaks found in archival data, one in 2005 and the other in 1981. In 2021, the project caught the attention of the astronomer at Caltech. She and a team of researchers went back in time to see how far back in time they could find this pattern.
They hit paydirt. There was more of a pattern in the data from the Haystack Observatory between 1975 and 1983.
When we realized that the peaks and troughs of the light curve matched the peaks and troughs observed between 1975 and 1983, we knew something was very special.
The signal is generated by the motion of the two black holes. When the black hole moves towards us, the radio light dims due to the motion of the jet, which causes a shift in the light's wavelength.
The data shows that this wave can be observed for eight years from 1976, after which it disappeared for 20 years. The supply of material feeding into the black hole may have changed. After 20 years, the pattern came back, and has continued ever since, according to the researchers.
The system called OJ 287 suggests that the interpretation is valid. The blazar has two black holes at a distance of a third of a light-year. The fluctuations in radio brightness are more irregular.
They could show us how to look for similar systems, even though we won't be around to see the merger of the black holes. These could bring us closer to understanding how these big accidents happen.
The research was published in a journal.
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