Scientists have discovered a giant black hole that grew much faster than its host galaxy billions of years ago. 

It is believed that in most cases, black holes and their galaxies expand at roughly the same rate, but new observations reveal that is not always the case, Yale University reported. The black hole looked at in the study formed roughly two billion years after the Big Bang, and was discovered during a project in which scientists worked to map the growth of supermassive black holes across cosmic time.

"Our survey was designed to observe the average objects, not the exotic ones," said C. Megan Urry, Yale's Israel Munson Professor of Astrophysics. "This project specifically targeted moderate black holes that inhabit typical galaxies today. It was quite a shock to see such a ginormous black hole in such a deep field."

The black hole is located in the galaxy CID-947 and is one of the most massive ever discovered, measuring in at over seven billion solar masses. The mass surrounding the black hole's galaxy took the scientists by surprise.

"The measurements correspond to the mass of a typical galaxy," said lead author Benny Trakhtenbrot, a researcher at ETH Zurich's Institute for Astronomy. "We therefore have a gigantic black hole within a normal-size galaxy."

The study challenges past ideas of how host galaxies grow in relation to black holes as well as the suggestions that radiation emitted by expanding black holes inhibits star production. The findings suggest CID-947 will likely continue to grow, and could one day evolve into something similar to the galaxy NGC 1277, which is one of the most extreme and massive galaxies known in the local universe.

 The team  research team included astronomers from Yale University, ETH Zurich, the Max-Planck Institute in Germany, Harvard University, the University of Hawaii, INAF-Osservatorio Astronomico di Roma, and Oxford University. The study was published in a recent edition of the journal Science.