A clear picture of NGC 4889, a supergiant elliptical galaxy, was taken by NASA’s Hubble Space Telescope. It shows that the galaxy contains a super massive black hole, which surprises scientist about its silent character. Scientists believe that there exist billions of galaxies in our observable universe and many of them have super massive black holes at their active centre.

When a black hole comes to its form, it starts absorbing stars and merging with other black holes to become super massive black hole. They are called super massive for their huge size. This new found supper massive black hole is of mass twenty-one billion times the mass of our Sun. it is formed at the center of NGC 4889, which is around 300 million light-years away in the Coma Cluster.

Though the astronomers were not able to detect the giant black hole, the instruments on the Keck II Observatory and Gemini North Telescope made it possible for them to determine its mass. The fact that velocities of stars orbiting center of NGC 4889 depend on the mass of the object they orbit, this helped the astronomers to take the measurements.

The observation also made it feasible to determine diameter of black hole’s event horizon, which is roughly 130 billion kilometer, approximately 15 times larger than the diameter of Neptune’s orbit from the Sun. The unusual and surprising factor the black hole displays is that it no longer observes the surrounding material and rather rests peacefully. However, when it was active it is believed to have used hot accretion to fuel itself.

It is thought that on its active period, the black hole may have expelled gigantic mass of galactic material into very energetic jets. On exhaustion of nearby supply of space material, the hole came to rest and fell silent.