Lifecycle of StarsBy: Mark and Jacob

NebulaA nebula is a cloud of gas and dust in space. Nebulae are the birthplaces of stars. There

are different types of nebula. Dark Nebula also exist. These are dense

clouds of molecular hydrogen which partially or completely absorb the light from stars behind them.

A protostar is one of the earliest stages in star format

It is a large object that forms from gas from a giant molecular medium.

Typically grows to the point of starting nuclear fusion.

Protostar

Brown DwarfA sub-stellar object that’s mass is between

that of a sun and a planet.They aren’t really brown, they’re a very dull

shade of red.They cannot perform nuclear fusion because

they are not hot enough

Main SequenceThe majority of the stars in out galaxy are

main sequence starsThey are all undergoing the fusion of

hydrogen to heliumIt’s the middle of a stars life.Main sequence stars consist of high density

gas and fluid.

Hydrogen FusionHydrogen atoms become extreamly hot.They collide and fuse together to form a helium

atom.The fusion cycle releases energy

Red GiantA large bright star with solar masses ranging

from 0.5-1.o that is still in the late phase of stellar evolution.

Close to the end of a star’s life the temperature at the core of it makes the star grow larger

Helium FusionA helium atom has to reach extream

temperatures to start fusion.They collide as well and fuse to form a carbon

atom.

This realases more energy than Hydrogen fusion

Occures in red giants/super giants

Planetary NebulaThey are formed by certain stars when they

die.They are a short phenomenon, lasting only

about a few ten thousand yearsThey hold an abundant amount of chemicalsThey are very faint, cannot be seen with the

naked eye

White DwarfA star that has exhausted all it’s nuclear fuel.A typical white dwarf has half the mass of the

sun, and is only a bit larger than the earthThey are one of the densest stars in

existence, supassed by neutron stars

Black DwarfBlack Dwarfs consist of cold and degenerate

matterIt is thought that it would take a star at least

a trillion years to cool down to become a black dwarf star.

It cannot emit heat or light.

Massive Main SequenceThe same events take place in a normal main

sequence.This sequence does not last as long as a

normal main sequence would. They burn through helium and hydrogen

much faster, which is the cause of they’re short life span

Red SupergiantIt has 10 times the mass of the sun.It’s lifespan can be anywhere from a few

hundred thousand to one million years longOnly about 200 red supergiants have been

found in the galaxyThey end in a massive explosion called a

supernova.

SupernovaA supernova is a stellar explosionThe explosion is so bright it is able to light up

a whole galaxyThe star loses most or all of it’s material

KABOOM!!!!

Neutron StarResults from a dead starIt is made by a gravitational collapse in a

supernovaNeutron stars are extremely hotIt’s mass is between 1.35 and about 2.1 solar

masses

Black HoleIt’s believed that black holes are made by

massive stars when they die off.Nothing, not even light, can escape from a

blackhole.A black hole’s density cannot be measured

SourcesWikipedia.comhttp://www.daviddarling.info/encyclopedia/B/

browndwarf.htmlhttp://imagine.gsfc.nasa.gov/docs/ask_astro/a

nswers/971016.htmlhttp://www.daviddarling.info/encyclopedia/B/

blackdwarf.html

http://en.wikipedia.org/wiki/Black_hole

More Sourceshttp://en.wikipedia.org/wiki/Neutron_starhttp://en.wikipedia.org/wiki/Main_sequencehttp://en.wikipedia.org/wiki/Brown_dwarfhttp://en.wikipedia.org/wiki/Supernovahttp://en.wikipedia.org/wiki/Red_supergianthttp://en.wikipedia.org/wiki/Hydrogen_fusionhttp://en.wikipedia.org/wiki/Planetary_nebulahttp://en.wikipedia.org/wiki/White_dwarf

Even more Sources http://en.wikipedia.org/wiki/Red_giant