Black Holes
1. Black holes are regions of
spacetime exhibiting gravitational
acceleration so strong that
nothing—no particles or even
electromagnetic radiation—can
escape from them.
2. They are formed from the
remnants of massive stars that
undergo gravitational collapse.
3. The boundary surrounding a
black hole, beyond which escape
,is impossible, is called the event
horizon.
4. The first black hole ever
discovered is Cygnus X-1,
identified as a candidate in 1964.
5. Stellar-mass black holes are
formed when massive stars
exhaust their nuclear fuel and
collapse under their gravity.
6. Supermassive black holes, with
millions or billions of times the
mass of our Sun, are found at the
centers of galaxies.
7. The largest known black hole,
TON 618, is estimated to be 66
billion times the mass of the Sun.
, 8. Black holes do not "suck"
everything around them; they
exert gravitational influence like
any other mass.
9. The term "black hole" was
coined by physicist John
Archibald Wheeler in 1967.
10. Despite their name, black
holes can be identified indirectly
through their gravitational effects
on nearby matter.
11. Interstellar gas falling into a
black hole can reach extreme
temperatures and emit X-rays
detectable from Earth.