Different size stars

[Dan]

A thought occurred to me, a star is formed by a large mass of hydrogen collapsing under its own gravity right? So how then do we get different size stars, because wouldn’t the hydrogen cloud collapse when it reached a certain mass making all stars the same size because they all started with the same amount of hydrogen?

 

Somewhere I’m wrong because there are lots of different size stars so can someone tell me what I’ve got wrong?

 

Many thanks

[D H]

All stars do not start with the same amount of hydrogen.

[Dan]

Yer, i want to know why.

[insane_alien]

different sized eddies in the medium that existed before the stars formed.

 

basically, the hydrogen gas that the stars formed out of was unevenly distributed which means different sized stars formed.

[Dan]

So if the hydrogen is more concentrated in certain areas it will need more dust and hydrogen to collapse and form a star, right? Or have I missed the point again?

[Spyman]

The molecular clouds have different size, temperature, pressure and internal movement. Gravity tries to pull the cloud together but is countered by it's pressure.

 

Either the temperature becomes cold enough for gravity to overcome the pressure or a disturbance of the cloud may upset its state of equilibrium.

 

Examples of disturbances are shock waves from supernovas, spiral density waves within galaxies and the close approach or collision of another cloud.

 

The gravitational collapse is not uniformly -> turbulent velocities generates filaments and clumps in the cloud over a wide range of sizes and densities. Several protostars might be created or ejected, depending on the size of the original cloud.

 

Computer animation of molecular cloud collapse: http://www.ukaff.ac.uk/starcluster/

[weknowthewor]

All happens due to scientific circumtencial evidence meet... one after another..