What molecules can form in a star?

Is there stellar chemistry that happens along side of nuclear fusion?
When elements are created do they tend to bond to themselves?
How else could you get for instance something like gold to always
be found with itself as a rule. This togtherness of likes looks like
the norm behind stellar chemistry and what eventually becomes
the planets.

What molecules start at the stars?

Mitchell Raemsch

On 14/09/2011 12:56 AM, jon car wrote:
[irrelevant groups dropped]
Is there stellar chemistry that happens along side of nuclear fusion?

In stars with cool enough outer layers, molecules are detected in those
layers via spectroscopy.

When elements are created do they tend to bond to themselves?

No. It's hot gases in the outer layers of cool stars, and ionized plasma
everywhere else in stars as a general rule.

How else could you get for instance something like gold to always
be found with itself as a rule.

Crystallization in a planet that's cooling and solidifying, or a magma
intrusion that's doing so. Like tends to clump with like, because if an
atom or molecule of species A tries to add itself to a growing crystal
of species B (or a growing hodgepodge) there will be more lattice
defects, and so higher energy, than if it tries to add itself to a
growing crystal of species A. The thermodynamically favored behavior is
thus for similar minerals to precipitate out into monospecific crystals.
Gold, in particular, tends to form clumps of native gold metal.

Minerals are also often found in association with particular other
minerals, generally because they have similar freezing points under the
pressures where crystallization tends to take place and their
constituent molecules tend to occur together in magmas.

This togtherness of likes looks like the norm behind stellar
chemistry and what eventually becomes the planets.

Actually, as outlined above the separation of minerals and grouping of
like with like is mainly a process that occurs inside forming planets
(and in vulcanism).

Though there is one crude separation that happens earlier, in a proplyd
when the central star ignites. The solar wind tends to blow atoms
outwards, and the lighter the atom the farther it gets blown and from
farther out from the star. So, bodies made primarily of ice, hydrogen,
ammonia, methane, and other light molecules of light elements form in
the outer solar system (hot Jupiters are thought to spiral inwards later
due to drag from accretion; what stops a Jupiter from sweeping all of
the proplyd inwards of its nucleation point and plunging into the star
is, 1. some, like our own Jupiter, run into a clear area usually created
by their own gravity making a band of orbits in the proplyd unstable
earlier and halt, and 2. the ones that sweep up most of the proplyd feel
tidal forces from the star when they get close and this can lock them
into a stable, resonant orbit; or the inner edge of the proplyd is
reached, inward of which the stellar wind blew away even the heaviest
elements). Rocky bodies are found farther in. Metal-dominated bodies are
either rocky ones that had enough heat of accretion to melt, so the
denser materials settled into the core, and then had their outer layers
blasted off, or formed very close to the star. (Mercury is probably a
little of both.)

And as noted denser materials settle to the cores of planets that get
hot enough during accretion to melt at least partially. Volcanic worlds
have some subsequent mixing, and impacts can also deliver dense
materials to near the surface (some of Earth's bigger nickel mines are
actually tunneling into asteroids that buried themselves in its crust
eons ago); vulcanism can also erupt light gasses to the surface from the
interior, replenishing an atmosphere of lighter elements even at
distances from the sun and for small enough worlds that the air slowly
leaks away into space. There is some debate about how long water locked
up in Earth's interior will replace what Earth loses to space, with the
Earth maybe drying out in 500 million years and maybe not until 2
billion years from now -- a difference by a factor of four, so not a
very precise knowledge as of yet!

What molecules start at the stars?

A few light ones. I'm not sure exactly which. Try Wikipedia or Google
for anything you have more questions about.

In article 2899c2dd-7c4a-41fb-8fe7-b9831b4d2a04
@g14g2000pre.googlegroups.com, says...

Is there stellar chemistry that happens along side of nuclear fusion?
When elements are created do they tend to bond to themselves?
How else could you get for instance something like gold to always
be found with itself as a rule. This togtherness of likes looks like
the norm behind stellar chemistry and what eventually becomes
the planets.

What molecules start at the stars?

Mitchell Raemsch

I am not sure if any bond can with stand combination
of hot surface temperature and breaking high energy radiation.
of stars in middle of their age.

For read giants it could be possible,
like H2, CO, NO

--
Poutnik

On 14/09/2011 06:42, Poutnik wrote:
In article2899c2dd-7c4a-41fb-8fe7-b9831b4d2a04
@g14g2000pre.googlegroups.com, says...

Is there stellar chemistry that happens along side of nuclear fusion?
When elements are created do they tend to bond to themselves?

Not inside a star it is way too energetic for any chemistry (a few eV)
to occur in the vicinity of a fusion reaction ( MeV).

How else could you get for instance something like gold to always
be found with itself as a rule. This togtherness of likes looks like
the norm behind stellar chemistry and what eventually becomes
the planets.

Gold only gets sorted when you have low enough temperatures for
diffusion limited reactions and/or gravitational sorting. It is a good
rule of thumb that only very young and very old rocks are gold bearing
as mineable ore. Middle aged rocks are gold poor.

Uranium is much more fickle and is present in most crustal rocks at
around 2ppm (relatively common) but seldom found as mineable grade ore.

What molecules start at the stars?

Mitchell Raemsch

I am not sure if any bond can with stand combination
of hot surface temperature and breaking high energy radiation.
of stars in middle of their age.

Depends mostly on the surface temperature and strength of the chemical
bond. You can see absorption lines for very strongly bonded molecules
like CN in the atmosphere of stars with surface temperatures of 4000K or
less (and that is still pretty hot).

For read giants it could be possible,
like H2, CO, NO

TiO is one of the more commonly observed absorption lines in red giants.
Other refractory oxides may also be present.

http://outreach.atnf.csiro.au/educat...ral_class.html

Has a table part way down in the spectral class summary section.

Regards,
Martin Brown

On Sep 14, 3:38*am, Martin Brown
wrote:
On 14/09/2011 06:42, Poutnik wrote:

In article2899c2dd-7c4a-41fb-8fe7-b9831b4d2a04
@g14g2000pre.googlegroups.com, says...

Is there stellar chemistry that happens along side of nuclear fusion?
When elements are created do they tend to bond to themselves?

Not inside a star it is way too energetic for any chemistry (a few eV)
to occur in the vicinity of a fusion reaction ( MeV).

How else could you get for instance something like gold to always
be found with itself as a rule. This togtherness of likes looks like
the norm behind stellar chemistry and what eventually becomes
the planets.

Gold only gets sorted when you have low enough temperatures for
diffusion limited reactions and/or gravitational sorting. It is a good
rule of thumb that only very young and very old rocks are gold bearing
as mineable ore. Middle aged rocks are gold poor.

Uranium is much more fickle and is present in most crustal rocks at
around 2ppm (relatively common) but seldom found as mineable grade ore.



What molecules start at the stars?

Mitchell Raemsch

I am not sure if any bond can with stand combination
of hot surface temperature and breaking high energy radiation.
of stars in middle of their age.

Depends mostly on the surface temperature and strength of the chemical
bond. You can see absorption lines for very strongly bonded molecules
like CN in the atmosphere of stars with surface temperatures of 4000K or
less (and that is still pretty hot).



For read giants it could be possible,
like H2, CO, NO

TiO is one of the more commonly observed absorption lines in red giants.
Other refractory oxides may also be present.

http://outreach.atnf.csiro.au/educat...sics/spectral_...

Has a table part way down in the spectral class summary section.

Regards,
Martin Brown

Sun is to hot to have molecules. It has the 4th state of matter called
plasma. In plasma we see atoms and molecules torn apart leaving
positive charged atomic nuclei,and electrons. TreBert

bert wrote:
On Sep 14, 3:38 am, Martin Brown
wrote:
On 14/09/2011 06:42, Poutnik wrote:

In article2899c2dd-7c4a-41fb-8fe7-b9831b4d2a04
@g14g2000pre.googlegroups.com, says...

Is there stellar chemistry that happens along side of nuclear
fusion? When elements are created do they tend to bond to
themselves?

Not inside a star it is way too energetic for any chemistry (a few
eV) to occur in the vicinity of a fusion reaction ( MeV).

How else could you get for instance something like gold to always
be found with itself as a rule. This togtherness of likes looks
like the norm behind stellar chemistry and what eventually becomes
the planets.

Gold only gets sorted when you have low enough temperatures for
diffusion limited reactions and/or gravitational sorting. It is a
good rule of thumb that only very young and very old rocks are gold
bearing as mineable ore. Middle aged rocks are gold poor.

Uranium is much more fickle and is present in most crustal rocks at
around 2ppm (relatively common) but seldom found as mineable grade
ore.



What molecules start at the stars?

Mitchell Raemsch

I am not sure if any bond can with stand combination
of hot surface temperature and breaking high energy radiation.
of stars in middle of their age.

Depends mostly on the surface temperature and strength of the
chemical bond. You can see absorption lines for very strongly bonded
molecules like CN in the atmosphere of stars with surface
temperatures of 4000K or less (and that is still pretty hot).



For read giants it could be possible,
like H2, CO, NO

TiO is one of the more commonly observed absorption lines in red
giants. Other refractory oxides may also be present.

http://outreach.atnf.csiro.au/educat...sics/spectral_...

Has a table part way down in the spectral class summary section.

Regards,
Martin Brown

Sun is to hot to have molecules. It has the 4th state of matter called
plasma. In plasma we see atoms and molecules torn apart leaving
positive charged atomic nuclei,and electrons. TreBert

The Sun's spectrum shows that there are some diatomic molecules like CN and
CH in the photosphere.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On 9/13/11 9/13/11 - 11:56 PM, jon car wrote:
Is there stellar chemistry that happens along side of nuclear fusion?

Yes. But it is chemistry appropriate for the enormous temperatures and high
densities, and thus varies throughout the star. It is also VERY different from
what we observe on earth, due to those very different conditions.

Few molecules form for very long ( femtoseconds), because the temperature and
density are high enough throughout most of the star to immediately disassociate
them. Near the surface the density can be low enough that molecules remain for
measurable durations.


When elements are created do they tend to bond to themselves?

Yes, for a few femtoseconds, then other atoms bump into them with sufficient
energy to disassociate any molecules.


This togtherness of likes looks like
the norm behind stellar chemistry and what eventually becomes
the planets.

The planets are VERY MUCH cooler than the stars, and this STRONGLY affects the
longevity of chemical bonds.


What molecules start at the stars?

Everything except hydrogen and helium (which does not form molecules) and tiny
amounts of Be and Li were formed in stars. At least in our best models today.


Tom Roberts