Sgr A*, the radio source associated with the central supermassive black hole, is quite underluminous as compared to black holes at the centers of other galaxies.
However, with the increased sensitivity provided by adaptive optics, the infrared emission
from material accreting onto Sgr A* has been detected. The emission is variable, and the
luminosity of Sgr A* can increase by a factor of a few over the stellar background during a single night.
However, during an observing session on Keck 2 Telescope on May 13th, 2019, we captured Sgr A* as it suddenly became 75 times brighter before subsiding back to normal levels. The timelapse of images over 2.5 hours is shown.
The results were published in the Astrophysical Journal article.
For more information, check out the following articles: CBS News, Live Science and space.com.