This document discusses black holes, galaxies, and quasars. Black holes are formed when giant stars collapse, leaving an intense gravitational field from which not even light can escape. Galaxies come in three main types - elliptical, spiral, and irregular. Spiral galaxies contain large amounts of gas and dust and are actively producing new stars. Quasars are thought to be the extremely bright cores of distant spiral galaxies that emit powerful radio waves and light.

1. Black
Holes

4. Black Holes
The intense
gravitational field left
when a giant star
collapses

6. It is called a black
hole because not
even light can
escape

9. Photon Sphere
The outer edge
where light bends but
is still escapable

10. Event Horizon
The point at which no
light can escape

11. Singularity
The shrunken star
too small to be
measured but with
indefinite density

13. Galaxies

14. Galaxy
A large assembly of
stars and nebulae

15. Group of Galaxies

16. The Milky Way
Our galaxy
Flat disk with spiral
arms

18. Three Types of
Galaxies

19. Elliptical
Oval shaped
Most common type
of galaxy found

20. Contains little gas
and dust
Most are dim and
difficult to see

22. Spiral
Dense center with
spiral arms
Bright and easy to
see

23. Contains large
amounts of gas and
dust – always
producing new stars

26. Irregular
No specific shape
Contains large
amounts of gas and
dust

27. Small and faint
therefore hard to see

29. Quasars

30. Quasars
Small, powerful
source of energy
thought to be cores
of distant spiral
galaxies

31. They emit radio
waves and bright
light

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