A team of scientists has detected increased activity in the supermassive black hole located at the center of the Milky Way galaxy. According to the scientists, the massive cosmic object's brightness has been fluctuating in the past couple of years.

Milky Way's supermassive black hole is known as Sagittarius A* (Sgr A*). Compared to other supermassive black holes, Sgr A* is not an active galactic nucleus. This means it does not glow brightly due to continuous feeding.

Detecting Increased Activity In Sgr A*

Sagittarius A*, black hole
Supermassive Black Hole Sagittarius A* X-ray: NASA/UMass/D.Wang et al., IR: NASA/STScI

However, during the past couple of years, Sgr A* stunned scientists by displaying increased activity. In a new study submitted for publication through ArXiv.org, a team of French and Belgian scientists revealed that the brightness of the supermassive black hole has been fluctuating.

Aside from this, the scientists also detected an increase in the emission of X-ray flares from the black hole. According to their findings, the number of X-ray flares spiked in the recent years, totaling 107 between 1999 and 2015. The scientists noted that the intensity of the flares began increasing after August 2014. "We detected an increase by a factor of about three in the flaring rate of the most luminous and most energetic flares that have occurred since 2014 Aug. 30," the scientists wrote in the study.

Identifying The Cause Of Sgr A* Activity

Black hole
This artist's concept illustrates a supermassive black hole with millions to billions times the mass of our sun. Supermassive black holes are enormously dense objects buried at the hearts of galaxies. (Smaller black holes also exist throughout galaxies.) In this illustration, the supermassive black hole at the center is surrounded by matter flowing onto the black hole in what is termed an accretion disk. This disk forms as the dust and gas in the galaxy falls onto the hole, attracted by its gravity. NASA/JPL-Caltech

The scientists were able to conduct their study and present their findings using data collected by space-based observatories. These include the Chandra X-ray Observatory, the XMM Newton and the Neil Gehrels Swift Observatory. Although unusual activity was detected coming from the black hole, it is not yet clear what's causing Sgr A*'s brightness fluctuation and increase in flare emissions.

According to the scientists, additional observations should still be conducted on the supermassive black hole in order to gather valuable data regarding its current state. "The X-ray activity of Sgr A* has increased for more than four years," the scientists stated. "Additional studies about the overall near-infrared and radio behavior of Sgr A* are required to draw strong results on the multiwavelength activity of the black hole."