SCIENCE FORM 2 STARS AND GALAXIES

11.1 STARS AND GALAXIES IN THE
UNIVERSE





TYPES OF GALAXIES PICTURE CHARACTERISTICS EXAMPLES
SPIRAL
1. Disc-shaped with spiral arms 1. Andromeda
ELLIPTICAL 2. Usually, the old stars are at 2. The Milky Way

IRREGULAR the centre while the young
stars at the edges.

1. Has a shape that is oval or 1. Ursa Major

round. 2. Messier 87

2. Bright at the core and dim at

the sides.

3. Consists mainly of old stars.

1. Does not have a definite or 1. Small Magellanic
specific shape. 2. Cloud and Large
3. Magellanic Cloud
2. The size of galaxy may
change.

3. The smallest galaxy consists
of dusts and gases.

4. Consists mainly of young
stars and nebulae

5. About 10% of galaxies that
exists are irregular galaxy.



















COLOUR

TEMPERATURE SIZE

CHARACTERISTICS TO
CLASSIFY STARS

BRIGHTNESS DISTANCE

Colour Surface temperature (°C) Example of star
Blue >25 000 Spica

Whitish-blue 11 000 - 25 000 Rigel
Bluish - white
7 500 - 11000 Sinus, Vega
White 6 000 - 7 500 Procyon, Capella
Yellowish-white 5 000 - 6 000
3 500 - 5000 Sun
Yellow Arcturus
Orange <3 500 Betelgeuse, Antares

Red









END