The document classifies stars based on their surface temperature and color. Class O stars are the hottest with temperatures over 25,000 K and a blue color. Class G stars like our Sun have temperatures between 5,000-6,000 K and are yellow. The coolest stars, Class M, are red and have temperatures below 3,500 K. As a star forms from a nebula, gravitational forces cause the gases and dust to collapse inward toward the core. As the core becomes denser and hotter, nuclear fusion begins, causing the star to shine. Medium stars end as white dwarfs, large stars as neutron stars, and super large stars as black holes.

2. Class Colour Surface Example
Temperature
O Blue > 25 000 Spica
B Whitish-blue 11 000 – 25 000 Rigel
A White 7 500 – 11 000 Sirius
F Yellowish-white 6000 – 7500 ProcyonA
G Yellow 5000 – 6000 The Sun
K Orange 3500 – 5000 Acturus
M Red < 3500 Betelgeuse

3.  Neutron star
 White dwarf
 The Sun
 Giant
 Supergiant

4. Star Distance (Light Years)
Sirius 9
Canopus 98
Alpha Centauri 4.3
Acturus 36
Vega 26
Capella 45
Rigel 900
Procyon 11
Achernar 118
Beta Centauri 490
In order of brightness ….

5. Nebulae pulled
Gravitational
Huge Clouds of inwards
Nebulae Pull between
Gases and Dust towards the
particles
core
Core
temperature & Gravitational
Start to spin Core compact
Pressure force increases
increases
Nuclear fusion
starts (15 000 Start to shine
degrees)

6.  Death of Medium-sized star
 Red giant >> White Dwarf >> Black dwarf
 Death of Large star
 Red giant >> Supergiant >> Supernova >> Neutron star
 Death of Super-Large star
 Red giant >> Supergiant >> Supernova >> Black hole

7.  Furthest galaxy – 10 000 million years apart
 Universe begin about 18 000 million years
ago as a result of a very huge explosion
 Scatter cosmic materials and hot gases in all
directions
 Scientists believe that the Universe is still
expanding and also breaking up