Black Hole

Professor Andrew King from the University of Leicester’s Department of Physics and Astronomy has stated that black holes at the heart of galaxies could swell to about 50 billion Suns before losing the discs of gas that they rely upon to expand. However, this gas can lose energy and fall inwards to feed the black hole, although they are known to be unstable and are prone to be crumbling into the stars.

King was calculating how big a black hole must be in order to keep its outer edge from forming a disc when he estimated the figure of 50 billion Suns. According to the study, the black hole would stop expanding upon reaching the 50 billion Sun limit. The only way it would expand thereafter, would be if a star happens to fall in or if there is another black hole merged with it.

According to Professor King, "The significance of this discovery is that astronomers have found black holes of almost the maximum mass, by observing the huge amount of radiation given off by the gas disc as it falls in". The findings were presented in a study titled 'How Big Can a Black Hole Grow’?