A new study shows that the supermassive black hole lurking at the center of our Milky Way galaxy isn’t as dormant as previously thought. According to a study published Wednesday in the journal NatureThe sleeping giant woke up about 200 years ago and ate some nearby space objects before falling asleep again.

NASA’s IXPE space observatory detected the X-ray echo of this powerful resurgence activity, the researchers said. Supermassive black hole Sagittarius A* (abbreviated as Sgr A*) is four million times more massive than the Sun. It is located at the center of the Milky Way spiral, 27,000 light-years from Earth. Last year, astronomers revealed for the first time the image of a black hole – or rather, the ring of glowing gas surrounding its black hole.

Sgr A* was “always thought of as a dormant black hole,” said Frédéric Marin, a researcher at France’s Strasbourg Astronomical Observatory and lead author of the study. Most supermassive black holes at the center of their galaxies go dormant after absorbing all the surrounding matter.

“Imagine a bear hibernating after eating everything around it,” Marin told AFP.

But an international team of researchers discovered in the late 19th century that Sgr A* awoke from its slumber and swallowed all sorts of gas and dust, unlucky enough to reach it. Feeding lasted from several months to a year before the animal went into hibernation again.

The echo emitted during the explosion of Sagittarius A* (located out of view) draws a circle in the image of the Galactic center. The brightness of the radiation sources (or echoes for IXPE) is converted into an audio spectrum 51 octaves below the actual frequencies (52 octaves for echoes). Credits: NASA/CXC/SAO/IXPE

Million times brighter

When active, the black hole was “at least a million times brighter than it is today,” Marin said. Its awakening was seen as nearby galactic molecular clouds began to emit significantly more X-ray light. The blast of X-ray light is like “a single firefly hidden in the forest suddenly becoming as bright as the Sun,” French research organization CNRS said in a statement.

Using NASA’s IXPE (Imaging X-ray Polarimetry Explorer) space observatory, astronomers were able to track the X-ray light and found it pointed directly at Sgr A*. Marin said the black hole “emits echoes of its past activity that we can observe for the first time.”

The gravity of black holes is so intense that nothing, including light, can escape. But when matter crosses the black hole’s final boundary, known as the event horizon, it emits enormous amounts of heat and light before disappearing into darkness. It remains unclear what exactly caused Sgr A* to briefly go out of silence. Can a star or a cloud of gas and dust get too close?

Astronomers hope that further observations from the IXPE observatory will help them better understand what happened and perhaps reveal more about the mysterious origins of supermassive black holes. Source