classical mechanics
2006-10-21 09:17:16 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Physics
We start with a cloud of interstellar material. if the material is dense and could enough it begin to collapse under gravity. It does this adiabatically. As it contracts it heats up. After time the internal temperature of the cloud becomes hot enough for the hydrogen (most galactic clouds ate 75% hydrogen) to ionise and the cloud becomes optically thick. Th cloud then begin to collapse under Kelvin-Helmholtz contraction - IE non adiabatically . At this point the cloud begins to radiate.
when the centre of the cloud hits about 2 million k nuclear fusion starts via the proton-proton chain. This creates enough energy to cause a large enough pressure gradient to stop the cloud from contracting further and the cloud enters a state of hydrostatic equilibrium. At this point I would consider this a stars - although it has yet to enter the main sequence. The actual details are a bit more complicated than this and many of the processes are yet to be fully understood.
It is important to note that p-p process is replace by the CNO cycle in stars over 4x10^30kg. Also we aware the fusion stops the stars contracting further and hence it is the on set of fusion that determines the radius of the star!
Give me a shout of you need to know more...
CyberCommie's
Minimum mass for a stars is 0.08 Solar masses. jupiter is nowere near massive enough.
2006-10-22 02:18:35 · answer #1 · answered by Mark G 7 · 0⤊ 0⤋
It is accreted from plasma, gas, dust and material ejected from super novae. Gravity draws it together along with some dark energy and matter. It coalesceses into a star by gravitational attraction, if it over a certain mass, hydrogen fusion starts and it is a star. Jupiter is just under the critical mass to start fusion, otherwise there would be 2 stars in this solar system.
2006-10-21 16:26:37 · answer #2 · answered by Anonymous · 0⤊ 0⤋
A star or celebrity can be born by a woman.
Like Michael Jackson for instance
2006-10-21 16:26:04 · answer #3 · answered by Anonymous · 0⤊ 1⤋
If you believe the hype, they go on X Factor, but after a while fall into a black hole never to be seen again.
2006-10-21 16:47:09 · answer #4 · answered by Anonymous · 0⤊ 1⤋
Suggest you take a look at
chronicle.uchicago.edu/040205/stars.shtml
Interesting and informative.
2006-10-21 16:21:22 · answer #5 · answered by Anonymous · 0⤊ 0⤋
something to do with dust and gas forming a supernova and black holes impolding. Good luck!!
2006-10-24 15:14:08 · answer #6 · answered by izzie269 1 · 0⤊ 0⤋
Special delivery?
2006-10-21 16:22:02 · answer #7 · answered by jonquilblack 4 · 0⤊ 1⤋
You'd have to ask my mum.
2006-10-21 16:30:56 · answer #8 · answered by Twisty 4 · 0⤊ 1⤋
THE MOTHER PUSHES.....
IF SHE'S LUCKY SHE'LL GIVE BIRTH, IF NOT...C-SECTION
2006-10-21 16:30:03 · answer #9 · answered by shiva1632 2 · 0⤊ 1⤋