Science 10.2

Galaxies

The 3 Galaxy Shapes

Spiral Galaxy

-Has many spiralling arms coming our from the centre core

-Very flat

-Milky Way is a spiral galaxy


Elliptical Galaxy

-Ranges from perfect sphere to stretched out ellipse

-Contain old stars

-50% of galaxies are elliptical

-Largest galaxies


Irregular Galaxy

-Does not have a regular shape

-Both new and old stars


Differences Between Galaxies

-Colour

-Number of stars

-Brightness

-Size

-Mass

-Speed of Spin

-Type of stars

-Amount of dust

-Amount of gas


Types of Star Clusters

Globular Cluster

-Held together by mutual gravity

-Up to 1,000,000 stars


Open Cluster

-From a few hundred to tens of thousands of stars


*Nebula*

-Cloud of dust and gas

-Often produces new stars

-Sometimes from a collapsed old star