it for astronomy presentation 2007 stars formation and evolution: interstellar medium to protostar...
TRANSCRIPT
IT for Astronomy Presentation 2007
StarsFormation and Evolution:Interstellar Medium to ProtostarProtostarsMain Sequence StarsGiants and DwarfsSupernovaThe Cycle restarts
IT For Astronomy Presentation 2007
Interstellar Medium to Protostar1. The ISM consists of gas and dust particles2. Regions may be viewed as clouds3. Some give off visible light, others weak radio waves4. Dense molecular clouds collapse5. Density is relative – virtual vacuum6. Colliding clouds can start gravitational compression7. Collapsing clouds fragment8. Molecules speed up and heat up9. Protostar starts to emit Infra Red radiation
IT For Astronomy Presentation 2007
Protostars
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
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..
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.
IT For Astronomy Presentation 2007
The Cycle Restarts