Sun Question

Does the Sun have an atmosphere and if so is there oxygen in it?

Seems to me that I recall that devoid of oxygen there can be no fire. The
Sun has fire.

Just Curious

Brian

Sun Question

Group: sci.astro.amateur Date: Thu, Jun 10, 2004, 5:54am (PDT+3) From:
(Amyotte)
Does the Sun have an atmosphere and if so is there oxygen in it?

I believe the outermost layer of the sun could be considered an
atmosphere, it is the corona.

Seems to me that I recall that devoid of oxygen there can be no fire.
The Sun has fire.

Well, I think that is in chemical reactions that for something to burn
it needs always oxygen. The sun generates heat in a nuclear reaction.
Ian

Just Curious
Brian

Brian, the Sun is poered by nuclear fusion!

óò
~

Hans Bethe worked out the basic nuclear processes by which hydrogen is
burned (fused) into helium in stellar interiors. Bethe described the
results of his calculations in a paper entitled "Energy Production
in Stars,'' which is awesome to read. He authoritatively analyzed
the different possibilities for reactions that burn nuclei and
selected as most important the two processes that we now believe
are responsible for sunshine. One process, the p-p chain, builds
helium out of hydrogen and is the dominant energy source in stars
like the sun and less massive stars. The neutrino data confirms
the models.

The Proton-Proton Chain
http://csep10.phys.utk.edu/astr162/l...y/ppchain.html
http://www.aip.org/enews/physnews/2003/split/629-2.html
Bahcall et al., Physical Review Letters, 4, April 2003

Competition between the P-P Chain and the CNO Cycle
http://csep10.phys.utk.edu/astr162/l...gy/cno-pp.html
http://www.aip.org/enews/physnews/2003/split/629-2.htm


Neutrino producing reactions adapted [by Lang] from Bahcall (1989). The
termination percentage is a fraction of terminations
of the proton-proton (pp) chain, 4p -- alpha + 2e+ + 2Ve, in which each
reaction occurs. Since in essentially all terminations at least one pp neutrino
is produced and in a few terminations one pp and one pep neutrino are created,
the total of pp and pep terminations exceeds 100%

Name Reaction % Termination Neutrino Energy, q
------------------------------------------------------------------------------
pp p + p -- H² + e+ + ve 100 q 0.420 MeV
pep p + e- + p -- H² + ve 0.4 q = 1.442 MeV
hep He³ + p -- He4 + ve 0.00002 q 18.773 MeV
Be7 Be7 + e- -- Li7 + ve 15 q = 0.862 MeV 89.7%
q = 0.384 MeV 10.3%
B8 B8 -- Be7 + e+ + ve 0.02 q 15 MeV


Calculated Solar neutrino fluxes at the Earth's Surface
------------------------------------------------------------------------------
pp 6.0 x 10^10 cm^-2 s^-1
pep 0.014 x 10^10 cm^-2 s^-1
hep 8 x 10^3 cm^-2 s^-1
Be7 0.47 x 10^10 cm^-2 s^-1
B8 5.8 x 10^6 cm^-2 s^-1

-Sam Wormley
http://edu-observatory.org/eo/sun.html

It uses Billy Goats Gruff instead of oxygen.
Clear, Dark, Steady Skies!
(And considerate neighbors!!!)

Depending upon what you mean by atmosphere, the sun is nothing but
atmosphere.
Thermal heat is why the sun glows, not from "fire" produced by oxidizing
something else.
There are trace amounts of all of the elements in the catalog - helium was
found first in the sun's spectra before it was found here on the Earth - so
yes, there will be oxygen in the sun's atmosphere. I'll note that it is so
hot that it really doesn't want to combine with other elements even with
some of its electrons stripped from the atoms.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works every time it is tried!

Thanks for the answers guys.

My wife, son and I were talking about the Venus Transit last night and
Teresa asked if space is a vacuum how does the sun burn. I couldn't answer
her.

Now I can.

Brian

"Amyotte" wrote in message
...
Does the Sun have an atmosphere and if so is there oxygen in it?

Seems to me that I recall that devoid of oxygen there can be no fire. The
Sun has fire.

Just Curious

Brian

"Amyotte" wrote in
:

Does the Sun have an atmosphere and if so is there oxygen in it?

Seems to me that I recall that devoid of oxygen there can be no fire.
The Sun has fire.

Just Curious

Brian



The Sun is too hot for molecular reactions like oxidation. No molecules
are stable at even the temperature of the Sun's photosphere (visible
surface). The surface of the Sun glows purely because it is hot, just
like an electric element glows when heated. The source of the heat is the
thermonuclear reactions occuring deep in the Sun's core as explained by
Sam Wormley in his post. You can think of it as a continuous H bomb
explosion going on in the core. The Sun's surface temperature - what we
see from Earth is around 6000 Kelvin or roughly 10100 deg farenheit the
temperature of the Sun's core is in the millions of degrees Kelvin and
there is enormous pressure as well. It is these extraordinary conditions
at the core that allows the thermonuclear reactions to continuously
occur.


Klazmon.

Amyotte wrote:

Does the Sun have an atmosphere and if so is there oxygen in it?

Seems to me that I recall that devoid of oxygen there can be no fire. The
Sun has fire.

Just Curious

Brian


Is this a troll or an indictment of where you went to junior high?
If a troll; simple but effective.
If not, other posters answered your question well, and tell your son to
pay more attention than you did in science class. ;-)

Shawn

Sam Wormley wrote:

Hans Bethe worked out the basic nuclear processes by which hydrogen is
burned (fused) into helium in stellar interiors. Bethe described the
results of his calculations in a paper entitled "Energy Production
in Stars,'' which is awesome to read. He authoritatively analyzed
the different possibilities for reactions that burn nuclei and
selected as most important the two processes that we now believe
are responsible for sunshine. One process, the p-p chain, builds
helium out of hydrogen and is the dominant energy source in stars
like the sun and less massive stars. The neutrino data confirms
the models.

According to our current solar model by Bahcall et al., the CNO chain
only contributes to 1.5% of the total solar luminosity. Hans Bethe had
originally proposed (incorrectly) that the CNO chain was the dominant
energy producing chain of nuclear processes. See for instance:

http://www.sns.ias.edu/~jnb/Papers/P...pCNO/paper.pdf

The current observational evidence puts the above percentage at less
than 7.3%.

Both pp and CNO produces helium nuclei from protons, but via different
processes - see below. CNO requires carbon as a reactant, for instance,
but not pp. Regarding neutrinos, because pp and CNO involve different
nuclear processes, the neutrino spectrum (i.e. the number of neutrinos
produced at a given energy) is also quite different for the two chains.
Hence verifying precisely the neutrino spectrum from the sun would also
confirm not only that nuclear reactions is the primary source of energy
production in the Sun, but also that the primary chain of nuclear
reactions is the pp cycle.

CNO cycle:
http://en.wikipedia.org/wiki/CNO_cycle

PP cycle (page 8):
http://www.sns.ias.edu/~jnb/Papers/P...cury/paper.pdf

Yi-Zen

Amyotte wrote:

My wife, son and I were talking about the Venus Transit last night and
Teresa asked if space is a vacuum how does the sun burn. I couldn't answer
her.

"Burning" is just one of the many phenomena that releases
massive amounts of energy. Nuclear fission or fusion (like
what occurs in nuclear reactors or nuclear bombs) is another
way that releases *really massive* amounts of energy (without
consuming oxygen). The interior of a light-bulb is indeed
vacuum (or almost), yet it emits light as a side-effect of
electricity flowing through the resistive filament.

Light is emited as a side-effect of releasing a lot of energy
(in fact, the light is part of the energy being released).

I'm not 100% sure, but I think that the Sun's energy production
is a lot more similar to a nuclear bomb than to "fire" as we
understand it (BTW, fire -- or flames, more specifically -- is
simply a bunch of gas that results from a chemical reaction,
and that is so hot that it becomes incandescent)

Cheers,

Carlos
--