1. Chapter 9 :
Stars & Galaxies
Galaxies

2. Present by:
• Adleena Adzmi 11th July
• Raihana Zuhaidi 17th August
• Anas Iyliawani 4th October

3. Meaning of :
• Galaxy is a gathering of billions of stars and
planets.
• Our solar system is in the galaxy called the Milky
Way .
o Galaksi merupakan kumpulan bintang-bintang yang
terdapat dalam Alam Semesta.
o Galaksi dalam mana sistem suria,
iaitu bumi dan matahari berada di dalamnya dikenali
sebagai Bima Sakti.

4. • 100 billion galaxies are currently known to
exist in the visible Universe
• Milky Way is a spiral galaxy
• Our Sun and Solar System lie on one of the
spiral arms – Orion Arm
• About 90 000 light years in diameter

5. Type of galaxy :
Spiral Elliptical Irregular

6. Spiral Galaxy
• Disc shape with spiral arms
• Consisting of old and young stars
• Older stars at centre
• Younger stars at are at the edges
• Young, hot and bright star
• Spin around the black hole making it “Spiral-
like”
• Eg : Milky Way and the Andromeda Galaxy

7. Spiral Galaxy

8. Elliptical Galaxy
• Flattened ball-shaped
• Oval and have no arms
• Consist mainly of old stars
• The most common type of galaxies
• The core of the galaxy is bright but its edges are
dim
• Formed from collisions of spiral galaxy
• They can be huge and they can be very small
• Small amount of hydrogen means no more stars
will bloom

9. Elliptical Galaxy

10. Irregular Galaxy
• Not formed into specific shapes
• The size of these galaxies can change
• There are among the smallest galaxies.
• Contain a lot of dust and gases
• Consist mainly of young stars
• The most uncommon type of galaxies
• 10% of the galaxies are irregular galaxies
• Eg : Large Magellanic Cloud

11. Irregular Galaxy

12. Thank you