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Zoom Astronomy
Astronomy Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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BLACK HOLES
A black hole is a massive object (or region) in space that is so dense that within a certain radius (the Schwarzschild radius, which determines the event horizon), its gravitational field does not let anything escape from it, not even light.



The Formation of Black Holes:
It is thought that giant stars (those with a mass over 3 times the mass of the Sun) will evolve into a red supergiant, a supernova, and then into a black hole. The typical black holes is believed to have a mass of roughly 10 times that of the Sun, but the range must be huge. For a typical black hole with a mass 10 times that of the Sun, the Schwarzschild radius would be roughly 18.6 miles (30 km).

The Phrase Black Hole:
The phrase 'black hole' was coined by the physicist John Archibald Wheeler; before Wheeler, black holes were called 'frozen stars.' Astronomers think that there may be a black hole at the center of each galaxy.


Zoom Astronomy
Astronomy Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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If the astronomy term you are looking for is not in the dictionary, please e-mail us.




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