black holes discovery and definition

2. Black Holes: Facts, Theory & Definition
•Black holes are some of the strangest and most
fascinating objects found in outer space. They
are objects of extreme density, with such strong
gravitational attraction that even light cannot
escape from their grasp if it comes near enough.

3. •Albert Einstein first predicted black holes in 1916
with his general theory of relativity. The term
"black hole" was coined in 1967 by American
astronomer John Wheeler, and the first one was
discovered in 1971.

4. Types of black holes
There are three types:
1. stellar black holes (small but deadly )
2. supermassive black holes (the birth of giants)
3. intermediate black holes (the birth of giants)

5. Black hole theory
•Black holes are incredibly massive, but cover
only a small region. Because of the
relationship between mass and gravity
•this means they have an extremely powerful
gravitational force. Virtually nothing can
escape from them — under classical physics,
even light is trapped by a black hole.

6. Interesting facts about black holes
1 . If you fell into a black hole, theory has long suggested that gravity
would stretch you out like spaghetti.
2. Black holes do not "suck." Suction is caused by pulling something
into a vacuum, which the massive black hole definitely is not.stead,
objets fall into them.
3. If a star passes too close to a black hole, it can be torn apart.

7. First ever black hole image released
•Astronomers have taken the first ever
image of a black hole, which is located in a
distant galaxy.

8. • It measures 40 billion km across - three million times the size
of the Earth - and has been described by scientists as "a
monster".
• The black hole is 500 million trillion km away and was
photographed by a network of eight telescopes across the
world .
• It was captured by the Event Horizon Telescope (EHT), a
network of eight linked telescopes.

9. • The image shows an intensely bright "ring of fire", as
Prof Falcke describes it, surrounding a perfectly
circular dark hole. The bright halo is caused by
superheated gas falling into the hole. The light is
brighter than all the billions of other stars in the
galaxy combined - which is why it can be seen at such
distance from Earth.
• The edge of the dark circle at the centre is the point at
which the gas enters the black hole, which is an object
that has such a large gravitational pull, not even light
can escape.

10. References :
1. BBC news website https://www.bbc.com/news/science-
environment-47873592
2. http://science.nasa.gov/astrophysics/focus-areas/black-holes/
3. Oldham, L. J.; Auger, M. W. (March 2016). "Galaxy structure from
multiple tracers – II. M87 from parsec to megaparsec
scales". Monthly Notices of the Royal Astronomical Society. 457 (1):
421–439. arXiv:1601.01323.
4. Anon (11 April 2019). "The woman behind first black hole
image". bbc.co.uk. BBC News.