The human eye is unable to see black holes in space,But telescopes with special tools can help find
black holes by seeing how they affect nearby stars.
In February,the japanese space agency sent its Astro-H satellite into orbit around the earth.
The satellite's job was to examine large structures in space,
like huge black holes that exist at the
center of most galaxies.
galaxies are large groups of stars.
scientists estimate there are between 100 and 200 billion galaxies in the universe.
The Astro-H satellite fell apart after only a month in space.
But in that short time,Astro-H was able to gather important information.
It sent back data about the perseus cluster-a grouping of
galaxies in the star constellation perseus.
The Perseus cluster is home to hundreds of galaxies.
They are 240million light yers from Earth .
Black holes are where the pull of gravity is so strong that not even light can escape.
Usualy they happen after very big ,supergiant stars explode.
The exploded star turns into something called a "supernova".
supernovas create the largest explosions in space
It is very bright,but short-lived.
The material remaining after the suoernova explosion collapses.
Gravity pulls,or crushes,all the matter into a very small space.
When light can no longer escape that space,it is known as a black holes.
The japanese satellite Astro-H was carrying an instrument called an X-ray spectrometer.
It was able to measure the way gas flows at the center of the Perseus cluster.
What it found was tha the superheated gas at the
center of the cluster flowed more calmly than researchers expected
And that told them something about how black holes work ,and how galaxies are formed.
Brian McNamra is an astrophysicist with the University of Waterloo in Canada.
And that gives us a very precise measurement of how much energy is
being pumped into this gas by supermassive
black holes.