The supermassive black hole at the centre of the Milky Way has been observed emitting continuous flares, as revealed by recent astronomical observations. The activity, detected using the James Webb Space Telescope (JWST), has been noted to occur across various timescales, with both short-lived and prolonged bursts being recorded. The findings contribute to the ongoing study of black holes and their interactions with surrounding matter, highlighting a level of variability that had not been fully understood before.
Flares Detected Across Multiple Observations
According to a study published in The Astrophysical Journal Letters, the JWST’s Near-Infrared Camera (NIRCam) was utilised to examine Sgr A* over multiple eight-to-ten-hour sessions, accumulating a total of two days’ worth of data over the past year. Researchers noted that flares occurred with varying intensity, with some lasting mere seconds, while others persisted for extended periods. The accretion disk surrounding the black hole was seen generating significant bursts up to six times per day, accompanied by smaller sub-flares.
As per reports, the flares are an expected phenomenon in supermassive black holes, though the unpredictable nature of Sgr A*’s activity sets it apart.
Potential Causes Behind Flare Activity
The mechanisms responsible for the flaring remain under investigation, with researchers considering multiple possible explanations. The study suggests that shorter, faint flares could be caused by minor disruptions within the accretion disk, akin to small ripples on a river’s surface. In contrast, brighter and more extended flares are believed to result from more substantial disturbances, possibly involving magnetic reconnection events, where charged particles accelerate to near-light speeds and release intense radiation bursts.
The phenomenon was compared to solar flares, explaining that while the sun’s surface experiences magnetic activity, the processes occurring near black holes are significantly more extreme. The NIRCam’s ability to observe two different infrared wavelengths allowed for further insights into the behaviour of these flares, with researchers noting a slight delay in the brightness of longer-wavelength emissions compared to shorter-wavelength events.
Future Observations Planned
A proposal has been submitted to conduct a continuous 24-hour observation of Sgr A* using the JWST to gain deeper insights into the flare activity. Researchers believe this extended observation period could reduce interference from background noise, allowing for a clearer analysis of potential patterns in the emissions.
