Black Holes

Black Holes

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

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

Photon Sphere

The outer edge where light bends but is still escapable

Event Horizon The point at which no light can escape

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

Galaxies

Galaxy A large assembly of stars and nebulae

Group of Galaxies

The Milky Way Our galaxy Flat disk with spiral arms

Three Types of Galaxies

Elliptical Oval shaped Most common type of galaxy found

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

Spiral Dense center with spiral arms Bright and easy to see

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

Irregular No specific shape Contains large amounts of gas and dust

Small and faint therefore hard to see

Quasars

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

They emit radio waves and bright light