The galaxy 3C 454.3 is located 7.2 billion light years away, but it's suddenly become the brightest source of gamma rays in the sky. Its particle jet has increased 10 times since the summer — and it's aimed at us.

According to a news release from NASA's Fermi Gamma Ray Space Telescope:

Astronomers identify the object as 3C 454.3, an active galaxy located 7.2 billion light-years away in the constellation Pegasus. But even among active galaxies, it's exceptional.

"We're looking right down the barrel of a particle jet powered by the galaxy's supermassive black hole," said Gino Tosti at the National Institute of Nuclear Physics in Perugia, Italy. "Some change within that jet — we don't know what — is likely responsible for these flares."

Blazars, like many active galaxies, emit oppositely directed jets of particles traveling near the speed of light when matter falls toward their central supermassive black holes. What makes a blazar so bright in gamma rays is its orientation: One of the jets happens to be aimed straight at us.


Here's the above image, with 3C 454.3 circled: