Star Formation

I just looked at the HST image of the Black eye galaxy and they explain that
vigorous star formation is occuring
where the outer dust and gas shears and mixes with the inner material to
form stars. I always wonder what
the conditions and density of hydrogen must be to form a huge sphere that
gravitationally collapses and what the rate
of aquiring hydrogen is to build up a massive body such as a star. Why
doesn't dust and material other than hydrogen interfere
with star formation and cause a chaotic failer and explosion? I really
can't comprehend this process that
takes place so often and results in galaxies of 100's of billions of stars.
How can that much hydrogen just happen to be in
such a situation and density and amount to start nucleation and building of
a star until a critical mass is reached?
How does a star actually ignite? and why doesn't it just blow up upon
ignition? How can a star be so stable when
it is born and happen over and over again in the universe? Does anyone have
a good idea?

They say that Jupiter may have been a failed star that didn't aquire enough
hydrogen but even that idea is strange because
as a body that size grows, hydrogen under pressure becomes metallic. It is
thought that Jupiter has a metallic hydrogen core!

So many questions.

The answer to why stuff will agglomerate is gravity. Any mass of material
is pulling on other masses of material, so even a tenuous cloud will pull on
other material and continue to grow. Then comes the pressure of all of the
stuff pulling together. Pressure leads to heat. When the temperature and
is high enough, hydrogen will begin to fuse giving off tremendous energy
that will stop the collapse. By the time that it reaches this temperature
(several billion degrees) there are no lasting chemical reactions that will
cause a traditional explosion. Hydrogen is what they always talk about
because hydrogen is the vast majority of the (known) material in the
universe.

Fusion does not take place like H-Bombs. In fact the only reason that
fusion is sustained is because of the huge amount of matter that is present.
Only a small fraction of the atoms in a star have enough energy to collide
with another atom to fuse. It becomes a low probablility collision and
therefore a relatively slow process.

Its not a critical mass, its a critical temerperature and pressure.

Jupiter has about 1/20th the mass necessary to collapse into a star. It
therefore just condensed and cooled into the largest planet in our solar
system.





"mikeS" wrote in message news:xpPVb.16608$Qa3.0@edtnps89...
I just looked at the HST image of the Black eye galaxy and they explain
that
vigorous star formation is occuring
where the outer dust and gas shears and mixes with the inner material to
form stars. I always wonder what
the conditions and density of hydrogen must be to form a huge sphere that
gravitationally collapses and what the rate
of aquiring hydrogen is to build up a massive body such as a star. Why
doesn't dust and material other than hydrogen interfere
with star formation and cause a chaotic failer and explosion? I really
can't comprehend this process that
takes place so often and results in galaxies of 100's of billions of
stars.
How can that much hydrogen just happen to be in
such a situation and density and amount to start nucleation and building
of
a star until a critical mass is reached?
How does a star actually ignite? and why doesn't it just blow up upon
ignition? How can a star be so stable when
it is born and happen over and over again in the universe? Does anyone
have
a good idea?

They say that Jupiter may have been a failed star that didn't aquire
enough
hydrogen but even that idea is strange because
as a body that size grows, hydrogen under pressure becomes metallic. It
is
thought that Jupiter has a metallic hydrogen core!

So many questions.

The answer to why stuff will agglomerate is gravity. Any mass of material
is pulling on other masses of material, so even a tenuous cloud will pull on
other material and continue to grow. Then comes the pressure of all of the
stuff pulling together. Pressure leads to heat. When the temperature and
is high enough, hydrogen will begin to fuse giving off tremendous energy
that will stop the collapse. By the time that it reaches this temperature
(several billion degrees) there are no lasting chemical reactions that will
cause a traditional explosion. Hydrogen is what they always talk about
because hydrogen is the vast majority of the (known) material in the
universe.

Fusion does not take place like H-Bombs. In fact the only reason that
fusion is sustained is because of the huge amount of matter that is present.
Only a small fraction of the atoms in a star have enough energy to collide
with another atom to fuse. It becomes a low probablility collision and
therefore a relatively slow process.

Its not a critical mass, its a critical temerperature and pressure.

Jupiter has about 1/20th the mass necessary to collapse into a star. It
therefore just condensed and cooled into the largest planet in our solar
system.





"mikeS" wrote in message news:xpPVb.16608$Qa3.0@edtnps89...
I just looked at the HST image of the Black eye galaxy and they explain
that
vigorous star formation is occuring
where the outer dust and gas shears and mixes with the inner material to
form stars. I always wonder what
the conditions and density of hydrogen must be to form a huge sphere that
gravitationally collapses and what the rate
of aquiring hydrogen is to build up a massive body such as a star. Why
doesn't dust and material other than hydrogen interfere
with star formation and cause a chaotic failer and explosion? I really
can't comprehend this process that
takes place so often and results in galaxies of 100's of billions of
stars.
How can that much hydrogen just happen to be in
such a situation and density and amount to start nucleation and building
of
a star until a critical mass is reached?
How does a star actually ignite? and why doesn't it just blow up upon
ignition? How can a star be so stable when
it is born and happen over and over again in the universe? Does anyone
have
a good idea?

They say that Jupiter may have been a failed star that didn't aquire
enough
hydrogen but even that idea is strange because
as a body that size grows, hydrogen under pressure becomes metallic. It
is
thought that Jupiter has a metallic hydrogen core!

"Thomas Koszuta" wrote in message
...
So many questions.

The answer to why stuff will agglomerate is gravity. Any mass of material
is pulling on other masses of material, so even a tenuous cloud will pull
on
other material and continue to grow. Then comes the pressure of all of the
stuff pulling together. Pressure leads to heat. When the temperature and
is high enough, hydrogen will begin to fuse giving off tremendous energy
that will stop the collapse. By the time that it reaches this temperature
(several billion degrees) there are no lasting chemical reactions that
will
cause a traditional explosion. Hydrogen is what they always talk about
because hydrogen is the vast majority of the (known) material in the
universe.

Fusion does not take place like H-Bombs. In fact the only reason that
fusion is sustained is because of the huge amount of matter that is
present.
Only a small fraction of the atoms in a star have enough energy to collide
with another atom to fuse. It becomes a low probablility collision and
therefore a relatively slow process.

Its not a critical mass, its a critical temerperature and pressure.

Jupiter has about 1/20th the mass necessary to collapse into a star. It
therefore just condensed and cooled into the largest planet in our solar
system.


This begs the question, Do stars grow quickly? Once the process of growing
begins, is there a critical mass
that is reached that builds stars such that so much gravity is present that
enormous amounts of hydrogen are
added to a stars structure at a high rate until actual ignition. It seems
logical that this is the case. Our suns core burns at 100's of millions of
degrees, not billions!

You seem to say that a star begins radiating fully in a gradual process as
more and more atoms are forced together so that it gradually
brightens.

"Thomas Koszuta" wrote in message
...
So many questions.

The answer to why stuff will agglomerate is gravity. Any mass of material
is pulling on other masses of material, so even a tenuous cloud will pull
on
other material and continue to grow. Then comes the pressure of all of the
stuff pulling together. Pressure leads to heat. When the temperature and
is high enough, hydrogen will begin to fuse giving off tremendous energy
that will stop the collapse. By the time that it reaches this temperature
(several billion degrees) there are no lasting chemical reactions that
will
cause a traditional explosion. Hydrogen is what they always talk about
because hydrogen is the vast majority of the (known) material in the
universe.

Fusion does not take place like H-Bombs. In fact the only reason that
fusion is sustained is because of the huge amount of matter that is
present.
Only a small fraction of the atoms in a star have enough energy to collide
with another atom to fuse. It becomes a low probablility collision and
therefore a relatively slow process.

Its not a critical mass, its a critical temerperature and pressure.

Jupiter has about 1/20th the mass necessary to collapse into a star. It
therefore just condensed and cooled into the largest planet in our solar
system.


This begs the question, Do stars grow quickly? Once the process of growing
begins, is there a critical mass
that is reached that builds stars such that so much gravity is present that
enormous amounts of hydrogen are
added to a stars structure at a high rate until actual ignition. It seems
logical that this is the case. Our suns core burns at 100's of millions of
degrees, not billions!

You seem to say that a star begins radiating fully in a gradual process as
more and more atoms are forced together so that it gradually
brightens.

mikeS wrote:


They say that Jupiter may have been a failed star that didn't aquire enough
hydrogen but even that idea is strange because
as a body that size grows, hydrogen under pressure becomes metallic. It is
thought that Jupiter has a metallic hydrogen core!

Jupiter would have had to been about 13 time more massive to have
started theonuclear fusion and more massive than that to sustain it.
See: http://www.astronomynotes.com/evolutn/s1.htm
http://www.edu-observatory.org/eo/solar_system.html

mikeS wrote:


They say that Jupiter may have been a failed star that didn't aquire enough
hydrogen but even that idea is strange because
as a body that size grows, hydrogen under pressure becomes metallic. It is
thought that Jupiter has a metallic hydrogen core!

Jupiter would have had to been about 13 time more massive to have
started theonuclear fusion and more massive than that to sustain it.
See: http://www.astronomynotes.com/evolutn/s1.htm
http://www.edu-observatory.org/eo/solar_system.html

"Sam Wormley" wrote in message
...
mikeS wrote:


They say that Jupiter may have been a failed star that didn't aquire
enough
hydrogen but even that idea is strange because
as a body that size grows, hydrogen under pressure becomes metallic. It
is
thought that Jupiter has a metallic hydrogen core!

Jupiter would have had to been about 13 time more massive to have
started theonuclear fusion and more massive than that to sustain it.
See: http://www.astronomynotes.com/evolutn/s1.htm
http://www.edu-observatory.org/eo/solar_system.html

I'm really not getting any decent discussion on this yet.

"Sam Wormley" wrote in message
...
mikeS wrote:


They say that Jupiter may have been a failed star that didn't aquire
enough
hydrogen but even that idea is strange because
as a body that size grows, hydrogen under pressure becomes metallic. It
is
thought that Jupiter has a metallic hydrogen core!

Jupiter would have had to been about 13 time more massive to have
started theonuclear fusion and more massive than that to sustain it.
See: http://www.astronomynotes.com/evolutn/s1.htm
http://www.edu-observatory.org/eo/solar_system.html

I'm really not getting any decent discussion on this yet.

mikeS wrote:

"Sam Wormley" wrote in message
...
mikeS wrote:


They say that Jupiter may have been a failed star that didn't aquire
enough
hydrogen but even that idea is strange because
as a body that size grows, hydrogen under pressure becomes metallic. It
is
thought that Jupiter has a metallic hydrogen core!

Jupiter would have had to been about 13 time more massive to have
started theonuclear fusion and more massive than that to sustain it.
See: http://www.astronomynotes.com/evolutn/s1.htm
http://www.edu-observatory.org/eo/solar_system.html

I'm really not getting any decent discussion on this yet.

The pressure and temperature have to be high enough for the pp-chain to
work. Gravitaional collapse initially provides the necessary temperature
for masses greater than about 13 Jupiters. Pressure is proportional to
the mass.

Metallic hydrogen can't exist at that temperature.