* Astronomy

Blobrana · L

RE: Solar supernova

Blobrana · L

Presolar Diamond

Blobrana · L

RE: Solar supernova

Blobrana · L

Where do we come from? The answer varies depending on how far back you want to look. Researchers are studying the oldest meteorite grains to figure out the origin of our solar system. Some of the planet-making material may have resulted from another galaxy smacking into ours.

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Blobrana · L

Asteroid-sized balls of magma hurtled through our infant solar system, and spray from their many collisions provided much of the raw material that formed Earth and its rocky siblings. That's according to a new take on an old theory that challenges the notion that the solar system started out as a placid sea of dust motes which simply clumped together to form planets.
The early family tree of our solar system's rocky planets features tiny glassy spheres called chondrules, found today inside ancient meteorites. The origins of chondrules, which are typically about a millimetre across, are shrouded in mystery. They make up much of the material preserved in meteorites that were formed about 2 million years after the solar system began and are thought to have clumped together to form asteroid-size planetesimals, which in turn agglomerated to make Earth and its peers.

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Blobrana · L

A 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 Maria Lugaro .

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Title: Fingerprints of a Local Supernova
Authors: Oliver Manuel, Hilton Ratcliffe

The results of precise analysis of elements and isotopes in meteorites, comets, the Earth, the Moon, Mars, Jupiter, the solar wind, solar flares, and the solar photosphere since 1960 reveal fingerprints of a local supernova (SN), undiluted by interstellar material. Heterogeneous SN debris formed the planets. The Sun formed on the neutron (n) rich SN core. The ground-state masses of nuclei reveal repulsive n-n interactions that trigger n-emission and a series of nuclear reactions that generate solar luminosity, the solar wind, and the measured flux of solar neutrinos. The location of the Sun's high-density core shifts relative to the solar surface as gravitational forces exerted by the major planets cause the Sun to experience abrupt acceleration and deceleration, like a yoyo on a string, in its orbit about the ever-changing centre-of-mass of the solar system. Solar cycles (surface magnetic activity, solar eruptions, and sunspots) and major climate changes arise from changes in the depth of the energetic SN core remnant in the interior of the Sun.

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Blobrana · L

Scientists are tracking the violent convulsions in the giant cloud of gas and dust that gave birth to the solar system 4.5 billion years ago via a few tiny particles from comet Wild 2.
These convulsions flung primordial material billions of miles from the hot, inner regions of the gas cloud that later collapsed to form the sun, out into the cold, nether regions of the solar system, where they became incorporated into an icy comet.

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Blobrana · L

For several decades, scientists have debated whether the Solar System formed as a result of a shock wave from an exploding star -- a supernova -- that triggered the collapse of a dense, dusty gas cloud that contracted to form the Sun and the planets. Now, astrophysicists have shown for the first time that a supernova could indeed have triggered the solar system's formation under conditions of rapid heating and cooling.

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Blobrana · L

Title: Meteorites and the physico-chemical conditions in the early solar nebula
Authors: Jerome Aleon

Chondritic meteorites constitute the most ancient rock record available in the laboratory to study the formation of the solar system and its planets. Detailed investigations of their mineralogy, petrography, chemistry and isotopic composition and comparison with other primitive solar system samples such as cometary dust particles have allowed through the years to decipher the conditions of formation of their individual components thought to have once been free-floating pieces of dust and rocks in the early solar nebula. When put in the context of astrophysical models of young stellar objects, chondritic meteorites and cometary dust bring essential insights on the astrophysical conditions prevailing in the very first stages of the solar system. Several examples are shown in this chapter, which include (1) high temperature processes and the formation of chondrules and refractory inclusions, (2) oxygen isotopes and their bearing on photochemistry and large scale geochemical reservoirs in the nebula, (3) organosynthesis and cold cloud chemistry recorded by organic matter and hydrogen isotopes, (4) irradiation of solids by flares from the young Sun and finally (5) large scale transport and mixing of material evidenced in chondritic interplanetary dust particles and samples returned from comet Wild2 by the Stardust mission.

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