By Thomas Fang
Black holes are still an immense mystery to us. We barely have any way of studying these great behemoths located thousands of light-years away. Being able to measure black holes could mean being able to analyze more about them, and possibly reveal the inner turnings of the universe. However, they are extremely hard to weigh, and to just even detect one takes great effort.
Previous Methods
There have been a few ways to estimate the mass of a black hole. One method is to study how gases closest to the black hole behave, and from that, estimate its mass. This takes years of gathering data and analysis, but may not work for every black hole. Another way is to measure a black hole’s diameter and then reveal its mass by using Einstein’s general theory of relativity. A black hole’s diameter can only be measured with the Event Horizon Telescope, and only one black hole has been measured thus far. Although that may change soon.
A New Possibility
Recently, astronomers have observed a new possible technique to weigh Black holes. Black holes surround themselves with a disk that flickers like a candle. A study led by graduate student Colin Burke and professor Yue Shen, detected changes in the accretion disk flickers which are related to the mass of the SMBH (Supermassive Black Holes). After gathering lots of data from SMBH’s flickering, Burke and Shen found a timescale for when the pattern changes. It is closely related to the mass of the SMBH. The team then did the same test on white dwarfs, which are remnants of smaller stars, like our sun, and discovered that the same correlation holds.
Future Advances
In the future, scientists may be able to use these relations to find IMBHs (Intermediate Mass Black Holes) in space as they will know exactly what disk flickers to look for in space to identify these space giants.
Although this is a much simpler method to weigh black holes than what was done previously, it is not the most efficient. It would take hundreds of days or even multiple years before we can estimate the mass of some supermassive black holes. Burke and Shen spent lots of time observing the sky and looking at past results to find this correlation. In the future, when the Vera C. Rubin observatory opens, work will be much simpler as it will scan the sky every few nights, and record data for how every dot flickers in the sky.
Working with the Center for Astrophysical Surveys at the National Center for Supercomputing Applications at Illinois, the team will continue their research.
“Now we know what to look for,” Burke says.