Solar system origin

Abstract—The isotopic anomalies of some extinct radionuclides testify to the outburst of a nearby
supernova just before the collapse of the protosolar nebula, and to the fact that the supernova was Sn Ia, i.e.
the carbon-detonation supernova. A key role of spallation reactions in the formation of isotopic anomalies
in the primordial matter of the Solar System is revealed. It is conditioned by the diffusive acceleration of
particles in the explosive shock waves, which leads to the amplification of rigidity of the energy spectrum of
particles and its enrichment with heavier ions. The quantitative calculations of such isotopic anomalies of
many elements are presented. It is well-grounded that the anomalous Xe-HL in meteoritic nanodiamonds
was formed simultaneously with nanodiamonds themselves during the shock wave propagation at the Sn Ia
explosion. The possible effects of shock wave fractionation of noble gases in the atmosphere of planets are
considered. The origin of light elements Li, Be and B in spallation reactions, predicted by Fowler in the
middle of the last century, is argued. All the investigated isotopic anomalies give the evidence for the
extremely high magneto- hydrodynamics (MHD) сonditions at the initial stage of free expansion of the
explosive shock wave from Sn Ia, which can be essential in solution of the problem of origin of cosmic rays.
The specific iron-enriched matter of Sn Ia and its MHD-separation in turbulent processes must be taking
into account in the models of origin of the Solar System.

Abstract
—The effects of the last supernova explosion before the formation of the Solar System are considered
using noble gases as examples. Acceleration of generated supernova matter in the explosive shock wave led to
its initial fractionation and to the formation of small-scale isotopic heterogeneity of primordial matter. This is
fixed as some isotopic anomalies in high-temperature phases of the earliest condensates of carbonaceous chondrites,
as well as in the isotopic systems of noble gases, and is the basis of the supernova phenomenon. Two
main manifestations of shock-wave acceleration in noble gases are investigated: the change in the isotopic ratios
of their cosmogenic components due to the increasing hardness of the spectrum of nuclear-active particles and
the fractionation of gases, namely, the enrichment of their isotopic systems with heavier isotopes. The reality
of the processes under consideration is demonstrated through the example of noble gases of solar corpuscular
radiation in lunar ilmenites. The absence of
r
-process products among extinct radionuclides in Ca- and Al-rich
inclusions (CAI) of carbonaceous chondrites with a formation interval of less than or equal to 1 Ma supports the
idea that the last supernova was an Ia-type supernova, which possibly played an important role in the origin of
the Solar System.
PACS: 96.12.Bc, 96.30.Za, 96.50.Pw, 97.60.Bw, 98.70.Sa
DOI:
10.1134/S0038094607030069

Introduction: Enstatite chondrites have a particular minera-logical composition which consists of silicates, sulfide, metal as major phases. But, were the chondrules of EH and EL chondrites originated from the genetic context? In order to answer to this question we have started to investigate on mesostasis chemical composition of chondrules in three thin sections: one from EET90299-EL3 chondrite and two from SAH97072-EH3. Major and minor elements contents in chondrules were analyzed by the electron microprobe (CNR, Padova, Italy). Results: For all the chondrules selected for investigating on mesostasis we found that although the range of Na 2 O: 3,52-7,31 wt%; Al 2 O 3 : 7,75-16,92 wt%; for the EL3 chondrules and Na 2 O: 4,55-8,05wt%; Al 2 O 3 : 11,19-17,87wt% for EH3 chondrules these contents are comparable. The average values for the chondrules of the two chondrites classes are comparable. There is also a good correlation between Al 2 O 3 and MgO that could be ex-plained as a func...

Abstract
—A possible new source of isotopic heterogeneity of primary matter in the solar system is recognized.
It is related to the specific radiation environment that arose at the passage of strong shock waves, which accompanied
a number of processes occurring during the formation of planetary systems: a possible supernova explosion,
collapse of the protosolar nebula, bipolar emission of proto-Sun matter, interaction of protosolar wind with
the accretion disk, etc. Acceleration in shock waves results in high integrated fluxes of active nuclear particles,
a high-energy spectrum of particles, and enrichment of the spectrum in heavy ions. This inevitably affects the
rates of formation and proportions of isotopes. The reworking of matter in the area of proto-Sun formation by
shock waves would certainly produce small-scale isotopic heterogeneities. They were conserved in the hightemperature
phases of early condensates and are registered in meteorites as isotopic anomalies. In the light of
this new concept, a number of problems are addressed including extinct radionuclides, abundances of light elements
(Li, Be, and B), and characteristic features of noble gas fractionation.

Introduction: Enstatite chondrites have a particular minera-logical composition which consists of silicates, sulfide, metal as major phases. But, were the chondrules of EH and EL chondrites originated from the genetic context? In order to answer to this question we have started to investigate on mesostasis chemical composition of chondrules in three thin sections: one from EET90299-EL3 chondrite and two from SAH97072-EH3. Major and minor elements contents in chondrules were analyzed by the electron microprobe (CNR, Padova, Italy). Results: For all the chondrules selected for investigating on mesostasis we found that although the87wt% for EH3 chondrules these contents are comparable. The average values for the chondrules of the two chondrites classes are comparable. There is also a good correlation between Al 2 O 3 and MgO that could be explained as a function of Al decay. The average CaO content is again comparable among chondrules in these three thin sections although seem to be li...