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A super giant black hole found

Astronomers from NASA’s Hubble Space Telescope and the Gemini Telescope in Hawaii have uncovered a super massive black hole in a massive elliptical galaxy, NGC 1600. It is located about 200 million light years from Earth and is 10 times more massive than it was predicted for a galaxy of this mass.

Until now the biggest supermassive black holes have been found in the core of very large galaxies. The current record holder weighs 21 billion suns and is located in the Coma galaxy cluster that consists of over 1,000 galaxies.

NGC 1600, the dominant galaxy in its galactic group, is at least three times brighter than its neighbours.

Most of the galaxy’s gas was consumed long ago when the black hole blazed as a brilliant quasar from material streaming into it that was heated into glowing plasma.

Black Hole

A black hole is a region of space time exhibiting such strong gravitational effects that nothing—including particles and even electromagnetic radiations such as light—can escape from inside it. It is formed at the end of the life of a massive star. It can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, a super massive black hole of millions of solar mass may form. There is generally thought that such super massive black holes exist in the centers of most galaxies.

Conditions necessary for Black hole formation

  • Very massive stars
  • Star is nearing its end of life cycle.
  • Its internal pressure fails to resist its own gravity. This happen when its core temperature is too less than its surface temperature. This condition is produced when, either
  1. The star has too little “fuel” left to maintain its temperature through stellar nucleosynthesis or
  2. It is in a position to receive extra matter in a way that does not raise its core temperature.

Stages in the life of a star

  1. MSS (Main Sequence Star): It is a stage of balance between the forces of nuclear reaction in the core (which lead to gaseous explosion and generate outward pressure) and compression and contraction (caused by inward forces of gravity generated by the huge mass of star).  It takes 50 million years for a solar mass to reach MSS.

More massive stars arrive at this stage sooner than the less massive stars. 

A star of the size of sun contains enough Hydrogen fuel to keep it going for about 10 billion years.  Whereas, a more massive star has less MSS time because they use up their fuel much faster.

  1. Red Giant Star: When the Hydrogen in the core are completely used up, core of the star starts shrieking. However, outer shell with some Hydrogen continues to release energy by fusion.  This upset the equilibrium in the star and outer shell expand enormously.  This enormous expansion has made it look like Giant and its colour changes to Red and therefore, it is called Red Giant Star.

Our sun will enter this stage in about 5,000 million years.

  1. Death of a Star: Death of a star varies according to the size of stars as defined by Chandra Shekhar Limit which is equal to 1.4 solar mass.
    • White Dwarf: If Stars’ mass is less than 1.4 times solar mass or less than 1 Chandrasekhar limit, then it tends to die as White Dwarf.
    • Pulsar/Neutron Star: If Stars’ mass is 1.4 solar mass to three Chandrasekhar limit then it tends to die as Neutron Star.
    • Black Holes: Stars with mass of more than three Chandrasekhar limit tends to die as Black holes.
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