IT For Astronomy Presentation 2007

1. IT for Astronomy Presentation 2007
Stars
Formation and Evolution:
Interstellar Medium to Protostar
Protostars
Main Sequence Stars
Giants and Dwarfs
Supernova
The Cycle restarts

2. IT For Astronomy Presentation 2007
Interstellar Medium to Protostar
1. The ISM consists of gas and dust particles
2. Regions may be viewed as clouds
3. Some give off visible light, others weak radio waves
4. Dense molecular clouds collapse
5. Density is relative – virtual vacuum
6. Colliding clouds can start gravitational compression
7. Collapsing clouds fragment
8. Molecules speed up and heat up
9. Protostar starts to emit Infra Red radiation

3. IT For Astronomy Presentation 2007
Protostars

4. IT For Astronomy Presentation 2007
Main Sequence Stars
 The Hertzsprung-Russell
diagram is a way of
categorising stars
 It plots luminosity versus
spectral colour which
relates to temperature
 Main sequence stars
with a range of masses
occupy a narrow band

5. IT For Astronomy Presentation 2007
Giants and Dwarfs
 Hydrogen fuel supply
exhausted in center –
outer parts expand to
form a Red Giant
 Eventually outer parts
shed to form a planetary
nebula and leave a
remnant White Dwarf
 Larger mass stars can
come to a worse end..

6. IT For Astronomy Presentation 2007
Supernova
1. Star explodes in
minutes.
2. May be visible to
naked eye.
3. Remanant shrinks
under own gravity.
4. May form Pulsar or
5. Black Hole.

7. IT For Astronomy Presentation 2007
The Cycle Restarts