New findings on the birth of the solar system
July 20, 2009A team of international astrophysicists, including Dr Maria Lugaro from Monash University, has discovered a new explanation for the early composition of our solar system.
The team has found that radioactive nuclei found in the earliest meteorites, dating back billions of years, could have been delivered by a nearby dying giant star of six times the mass of the sun.
Dr Lugaro said the findings could change our current ideas on the origin of the solar system.
"We have known about the early presence of these radioactive nuclei in meteorites since the 1960s, but we do not know where they originated from. The presence of the radioactive nuclei has been previously linked to a nearby supernova explosion, but we are showing now that these nuclei are more compatible with an origin from the winds coming from a large dying star," Dr Lugaro said.
The conclusion was reached by combining stellar observations from telescopes with recently developed theoretical models reproduced on powerful computers of how stars evolve and which nuclear reaction occurs within their interiors.
"We need to know if the presence of radioactive nuclei in young planetary systems is a common or a special event in our galaxy because their presence affected the evolution of the first large rocks (the parent bodies of asteroids and meteorites) in the solar system. These are believed to be the source of much of earth's water, which is essential for life," Dr Lugaro said.
"Within one million years of the formation of the solar system the radioactive nuclei decayed inside the rocks where they were trapped, releasing high-energy photons, which caused the rocks to heat. Since much of earth's water is believed to have originated from these first rocks, the possibility of life on earth depends on their heating history and, in turn, on the presence of radioactive nuclei." Dr Lugaro said.
"What we need to do now is investigate the probability that a dying giant star could have actually been nearby our then young solar system and polluted it with radioactive nuclei. This will inform us on the place where the solar system was born, on the probability that other young planetary system also are polluted with radioactive nuclei, and, eventually, on the probability of having water on terrestrial planets in other planetary systems."
More information: The findings have been published in the journal Meteoritic & Planetary Science.
Source: Monash University (news : web)
Oct 04, 2006 |
not rated yet |
0
Dr. Lurgo "has found that radioactive nuclei found in the earliest meteorites, dating back billions of years, could have been delivered by a nearby dying giant star of six times the mass of the sun."
Yes, that finding was published in several papers over three decades ago:
1. "Elemental and isotopic inhomogeneities in noble gases: The case for local synthesis of the chemical elements", Transactions Missouri Academy Sciences 9 (1975) 104-122.
2. "The xenon record of element synthesis", abstract P58, presented at the 1976 AGU Meeting, Sheraton Hotel, Washington DC, April 14 (1976).
3. "Xenon record of the early solar system", Nature 262 (1976) 28-32.
4. "Strange xenon, extinct super-heavy elements and the solar neutrino puzzle", Science 195 (1977) 208-209.
5. "Proceedings of Robert Welch Foundation Conference on Chemical Research XII. Cosmochemistry," Robert Welch Foundation (1978) 263-272.
"Dr Lugaro said the findings could change our current ideas on the origin of the solar system."
Yes indeed. Those results from the mid-1970s showed us that Earth's heat source is the unstable remains of a supernova that exploded 5 Gyr ago! See: "EARTH'S HEAT SOURCE - THE SUN", Energy and Environment: SPECIAL ISSUE: Natural drivers of weather and climate, volume 20 (2009) 131-144. http://arxiv.org/pdf/0905.0704
Oliver K. Manuel
Now the question is how would a neutron star evaporate? By neutral neutrino radiation, of course, over the eons. This is what is proposed in "An Alternative to the Standard Model of Physics".
http://www.scribd...-Physics
ANSWERS:
1a. Our Sun has a much older history.
1b. It exploded as the supernova 5 Gyr ago
---[Based on combined U/Pb and Pu/Xe age dating.
1c. It ejected all of the material that now orbits the Sun.
1d. Neutron stars "evaporate" by neutron emission
---[Driven by repulsive interactions between neutrons].
1e. The free neutrons decay to protons and electrons.
1f. Strong magnet fields at the core accelerate protons upward by strong.
---[Protons from the core are the carrier gas that maintains mass separation]
1g. Most protons are fused into He-4 during the upward journey
---[This generates 35% of solar luminosity; 100% of solar neutrinos]
1h. 50,000 billion metric ton of H reach the solar surface annually
---[This generates 100% of the solar wind Hydrogen].
2. Neutron-emission, driven by repulsive interactions between neutrons.
All this was explained in detail over the past 30 years and is summarized in "The Sun is a plasma diffuser that sorts atoms by mass," Physics of Atomic Nuclei 69 (2009) 1847-1856; Yadernaya Fizika 69, number 11, (November 2006); PAC: 96.20.Dt DOI: 10.1134/S106377880611007X
http://arxiv.org/.../0609509
With kind regards,
Oliver K. Manuel
Thanks, Barakn, for your comment.
EXPERIMENTAL DATA convincingly showed over three decades ago that isotopic anomalies and radioactivity in the early solar system DID COME from a supernova.
See: "Isotopes of tellurium, xenon and krypton in Allende meteorite retain record of nucleosynthesis," Nature 277, 615 - 620 (22 February 1979); doi:10.1038/277615a0 http://www.nature...5a0.html
With kind regards,
Oliver K. Manuel
http://www.omatumr.com