Understanding stellar explosions is less straightforward than previously thought

Apr 30, 2009

(PhysOrg.com) -- Stellar explosions called novæ are caused by nuclear reactions between the star's atoms. In order to better understand such violent phenomena, astrophysicists study the radiation emitted by certain types of atom, and in particular the fluorine-18 produced by these reactions.

Now, researchers at GANIL (The French large heavy-ion located in Caen), in collaboration with teams from the UK, Belgium, Romania and France, have determined that fluorine-18 appears to be less abundant than expected. This discovery therefore reduces the chances of observing the radiation emitted by this atom. It implies new constraints for the observation and understanding of novæ. This work has just been published in the journal .

Observed since ancient times, novæ are stellar explosions which occur in our galaxy around 20 times a year. Today, physicists think that they take place in stellar binary systems, which are made up of two stars, a red giant and a small, hot companion called a white dwarf. "Matter is torn off the red giant and falls onto the surface of the white dwarf," explains François de Oliveira Santos, a physicist working at GANIL. "This stellar matter accumulates on the surface of the white dwarf, leading to an increase in its temperature and density. A number of nuclear reactions, transforming one or more atomic nuclei into other particles, then take place: stable atomic nuclei (carbon, oxygen, etc) in the star are transformed into radioactive nuclei, such as fluorine-18." It is by observing the radiation emitted by these particles that researchers hope to better understand the physical processes taking place during novæ.

Fluorine-18 is a radioactive atom whose unstable nucleus is deficient in compared to its stable form, fluorine-19. When it disintegrates, fluorine-18 emits specific electromagnetic radiation that astrophysicists study in order to get a better understanding of what goes on inside novæ. "The amount of emitted during the explosion depends on the amount of fluorine-18 present," de Oliveira Santos explains. In order to show this, researchers have tried to identify all the nuclear reactions that lead to the creation and destruction of fluorine-18. Since these reactions depend on the structure of the nuclei, they have been studied with the use of particle accelerators.

An experiment carried out at Louvain-la-Neuve University in Belgium, as part of an international collaboration, has led scientists to revise downwards their estimate of the amount of fluorine-18 present in novae. The conclusion is that nuclear reactions involving fluorine-18 in these explosions lead to its destruction to a greater degree than had previously been estimated. "Our result is in agreement with recent theoretical work," de Oliveira Santos points out. "We obtained this result thanks to a new experimental technique that uses beams of accelerated radioactve nuclei." It leads to new constraints for the observation and understanding of stellar explosions.

More information: Discovery of a New Broad Resonance in 19Ne : Implications for the Destruction of the Cosmic -Ray Emitter 18F. J. C. Dalouzy, L. Achouri, M. Aliotta, C. Angulo, H. Benhabiles, C. Borcea, R. Borcea, P. Bourgault, A. Buta, A. Coc, A. Damman, T. Davinson, F. de Grancey, F. de Oliveira Santos, N. de Séréville, J. Kiener, M. G. Pellegriti, F. Negoita, A. M. Sánchez-Benítez, O. Sorlin, M. Stanoiu, I. Stefan, and P. J. Woods, Physical Review Letters. 24 April 2009

Provided by Laboratoire CNRS EN LUTTE- Physique et Mecanique des Miliieux Heterogeneous (news : web)

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omatumr
1 / 5 (3) Apr 30, 2009
NEUTRON REPULSION POWERS COSMIC EXPLOSIONS

Systematic properties of rest masses of the 3,000 different types of atomic nuclei that comprise the visible universe reveal repulsive interactions between neutrons as the energy source that powers the Sun, ordinary stars, and cosmic explosions [1].

The concept of a Hydrogen-filled cosmos created by a Big Bang is now obsolete [1].

[1] See: On the cosmic nuclear cycle and the similarity of nuclei and stars, Journal of Fusion Energy 25 (2006) pp. 107-114; DOI:10.1007/s10894- http://arxiv.org/.../0511051

With kind regards,
Oliver K. Manuel
http://www.omatumr.com
superhuman
5 / 5 (2) May 01, 2009
Yes, neutrons repulse each other just as protons do but how is this supposed to be an energy source? The repulsion itself is not enough to extract energy as evidenced by magnets.
laserdaveb
5 / 5 (1) May 01, 2009
"neutrons repulse each other just as protons do"? by what mechanism? not charge..i know i'm ignorant,so point me to the proof of that statement.
omatumr
1 / 5 (2) May 01, 2009
laserdaveb said: "neutrons repulse each other just as protons do"? by what mechanism? not charge..i know i'm ignorant,so point me to the proof of that statement.

The proof that the n-n interaction is repulsive is in the nuclear rest mass data points of the 3,000 different types of atoms that comprise the entire visible universe.

Here are the data: http://www.omatumr.com/Data/2000Data.htm" title="http://http://www.omatumr.com/Data/2000Data.htm" rel="nofollow" target="_blank">http://www.omatum...Data.htm

Here are a few of the early papers where the n-n repulsion is discussed:

1. "Attraction and repulsion of nucleons: Sources of stellar energy", J. Fusion Energy 19, 93-98 (2001)

2. "The Sun s origin, composition and source of energy", in Lunar and Planetary Science XXIX, Abstract 1041, available as 1041-pdf from Lunar and Planetary Institute, Houston, TX (CD-ROM, 2001)

3. "Nuclear systematics: III. The source of solar luminosity", J. Radioanal. Nucl. Chem. 252, 3-7 (2002)

4. The Sun s origin and composition: Implications from meteorite studies", Proceedings of Asteroids, Comets, Meteors (ACM 2002), 29 July - 2 August 2002, Technical University Berlin, Berlin, Germany (ESA-SP- 500, editor: Barbara Warmbein), pp. 787-790 (2003)

5. "The standard solar model versus experimental observations", Proceedings of the Third International Conference on Beyond Standard Model Physics - BEYOND 2002 (IOP, Bristol, editor: H. V. Klapdor-Kleingrothaus) pp. 307-316 (2003)

6. "Neutron repulsion confirmed as energy source", J. Fusion Energy 20, 197-201 (2003)

7. "Composition of the solar interior: Information from isotope ratios", Proceedings of the SOHO 12 / GONG 2002 Conference on Local and Global Helioseismology: The Present and the Future, 27 October-1 November 2002, Big Bear Lake, CA, U.S.A. (ESA SP-517, editor: Huguette Lacoste) pp. 345-348 (2003)

With kind regards,
OLiver K. Manuel
http://www.omatumr.com

omatumr
1 / 5 (2) May 01, 2009
"Yes, neutrons repulse each other just as protons do but how is this supposed to be an energy source?"

Energy is released when the neutrons are separated:

a.) Neutron-emission

b.) Fragmentation

c.) Fission

See: On the cosmic nuclear cycle and the similarity of nuclei and stars, Journal of Fusion Energy 25 (2006) pp. 107-114; DOI:10.1007/s10894- http://arxiv.org/.../0511051

or http://arxiv.org/.../0511379

With kind regards,
Oliver K. Manuel
http://www.omatumr.com
superhuman
5 / 5 (2) May 02, 2009
"neutrons repulse each other just as protons do"? by what mechanism? not charge..i know i'm ignorant,so point me to the proof of that statement.


Strong interactions, one simple proof is the lack of stable nuclei containing only neutrons or only protons, a more complicated explanation is that neutrons and protons are fermions (spin 1/2 particles) and identical fermions cannot occupy exactly the same state (Pauli exclusion principle) so if two fermions come too close a strong force will drive them away.

Energy is released when the neutrons are separated:
a.) Neutron-emission
b.) Fragmentation
c.) Fission


Both neutron emission (which only happens when nuclides have excess neutrons) and fission are well known so I don't understand what new energy source you are talking about.
omatumr
1 / 5 (2) May 02, 2009
Superhuman,

Do you understand that:

a.) Neutrons do not drip from neutron-rich nuclei, and

b.) Fission fragments do not drift apart slowly?

Do you not know that these are violent, energetic processes?

Please take a few minutes to study and think about information recorded in this CRADLE OF THE NUCLIDES:

http://www.omatumr.com/Data/2000Data.htm" title="http://http://www.omatumr.com/Data/2000Data.htm" rel="nofollow" target="_blank">http://www.omatum...Data.htm

With kind regards,
Oliver K. Manuel
http://www.omatumr.com


laserdaveb
not rated yet May 03, 2009
thank you superhuman..your more "complicated" explanation was helpful.

Oliver, i'm reading my way through your publications as time permits..but i'm still at the "hmmm" level.
omatumr
1 / 5 (1) May 04, 2009
THE JOY OF CONTINUOUS DISCOVERY

Take your time, laserdaveb.

I started research on the origin of the solar system in 1960 and have enjoyed almost 50 years of continuous discovery.

I cannot imagine a more joyous path through life!

With kind regards,
Oliver K. Manuel
http://www.omatumr.com
Lao Tzu : "To know that you do not know is best,
To pretend to know what you do not know is a disease."

superhuman
not rated yet May 05, 2009
Superhuman,
Do you understand that:
a.) Neutrons do not drip from neutron-rich nuclei, and
b.) Fission fragments do not drift apart slowly?
Do you not know that these are violent, energetic processes?
Please take a few minutes to study and think about information recorded in this CRADLE OF THE NUCLIDES:


I do know that fission can be very energetic but this is well known and since you talk about completely novel energy source I would like to know how your theory differs from standard theory.

In standard theory only nuclides with excess neutrons undergo fission, so if you claim this is the source of Sun's energy you would need to explain where do those nuclides with excess neutrons come from.

I like your cradle of nuclides but I don't see anything special about it. To extract energy from a nucleus you have to transmute it into another lying lower on this graph of yours, depending on the nuclide you start with you would have to either add or subtract neutrons. Since you say Sun's energy comes from neutron repulsion can you say which nuclides are transmuted into which?

I do find your Sun model interesting though in that I find it quite probable the Sun has a heavy core and that our Solar System was created as you picture it in one of those publications - when a similarly layered star exploded. On the other hand my knowledge in this area is very limited so I don't know how it compares to currently accepted models.
omatumr
1 / 5 (2) May 05, 2009
Thanks, Superman.

Physics World has a discussion of the book, "Sun in a Bottle: The Strange History of Fusion and the Science of Wishful Thinking" by Charles Seife (2008 Viking Books) that may be helpful.

It took me 50 years to figure out that the Sun is not a ball of Hydrogen and that Hydrogen is the exhaust gas, not the fuel, that powers the Sun.

With kind regards,
Oliver K. Manuel
http://www.omatumr.com
Alizee
May 06, 2009
This comment has been removed by a moderator.
omatumr
not rated yet May 06, 2009
Alizee,

Please provide a reference.

Thanks,
Oliver K. Manuel
omatumr
1 / 5 (1) May 08, 2009
WAKE UP, ALIZEE

Please provide a reference for your very strange statement that, "the solar antineutrino/neutrino flux ratio is lower then 1.7% with 90% confidence range."

You may want to read our paper on "The need to measure low energy anti-neutrinos (E < 0.782MeV) from the Sun," Phys. Atom. Nucl. 67 (2004) pages 1959-1962; Yad. Fiz. 67 (Russian, 2004) pages 1983-1986.

http://arxiv.org/.../0410168

With kind regards,
Oliver K. Manuel
http://www.omatumr.com