Astronomers say 'unusual brightness' in far away galaxy may be awakening of massive black hole

International scientists say the brightness was caused by a massive black hole becoming active and "feasting" on surrounding gas more than 300 million light-years away.

If the findings are validated in other studies, it would be the first time a black hole has been observed becoming active in real time.

Paula Sanchez Seez from the European Southern Observatory (ESO) says this behaviour is unprecedented: "Imagine you’ve been observing a distant galaxy for years, and it always seemed calm and inactive.

“Suddenly, its core starts showing dramatic changes in brightness, unlike any typical events we’ve seen before.”

Researchers compared data from ESO's Very Large Telescope with other earth-based telescopes.

They found the galaxy, named SDSS1335+0728, to be emitting more light at infrared, optical and ultraviolet wavelengths than previously.

Lorena Hernandez Garcia, from the Millennium Institute of Astrophysics and the Valparaiso institute in Chile said: "The most tangible option to explain this phenomenon is that we are seeing how the core of the galaxy is beginning to show activity.

"If so, this would be the first time that we see the activation of a massive black hole in real time."

The scientists said their findings will give a valuable insight into the fate of Sagittarius A, the massive black hole at the centre of the Milky Way.

But teams said more observations are needed to rule out different explanations, such as tidal events, where a star is torn apart by a black hole.

Massive black holes exist at the heart of most galaxies, sometimes having masses more than 100,000 times that of the Sun.

The gravity is so strong inside them that light cannot escape and normal laws of physics cease to apply.

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