Related papers: Presolar Grains from Novae
Nucleosynthetic isotope anomalies in meteorites allow distinguishing between the non-carbonaceous (NC) and carbonaceous (CC) meteorite reservoirs and show that correlated isotope anomalies exist in both reservoirs. It is debated, however,…
The bulk chemical compositions of planets are uncertain, even for major elements such as Mg and Si. This is due to the fact that the samples available for study all originate from relatively shallow depths. Comparison of the stable isotope…
Classical novae are potential gamma-ray emitters, both in lines and in a continuum. Continuum emission (at energies between 20-30 and 511 keV) and line emission at 511 keV are related to positron annihilation and its Comptonization in the…
The physical mechanism driving mass ejection during a nova eruption is still poorly understood. Possibilities include ejection in a single ballistic event, a common envelope interaction, a continuous wind, or some combination of these…
We analyzed spectra, trajectories, orbits, light curves, and decelerations of eight Draconid meteors observed from Northern Italy on October 8, 2011. Meteor morphologies of two of the meteors are also presented, one of them obtained with a…
The unique elemental abundance pattern of the carbon-rich stars CS29498-043 and CS22949-037 is characterized by a large excess of magnesium and silicon in comparison with iron. This excess is investigated in the context of a…
Of the ``presolar particles'' extracted from carbonaceous chondrite dissolution residues, i.e. of those particles which show isotopic evidence of solidification in the neighborhood of other stars prior to the origin of our solar system, one…
The origin of the heavily fractionated reservoir of nitrogen in comets remains an issue in the theory of their formation and hence of the solar system. Whether the fractionated reservoir traced by comets is inherited from the interstellar…
The abundant forms in which the major elements in the universe exist have been determined from numerous astronomical observations and meteoritic analyses. Iron (Fe) is an exception, in that only depletion of gaseous Fe has been detected in…
The composition of present day cosmic rays (CRs) is inconsistent with a significant acceleration of SN ejecta material (even with a preferential acceleration of ejecta grain material). Current CRs must result mainly from the acceleration of…
It is generally agreed that interstellar dust grains consist of two main components, namely, silicates and graphites. Some models, like MRN model, assume these grains to be homogeneous spheres following a power law size distribution. This…
The supernova yields of several heavy elements including alpha-, iron-group, and r-process elements are obtained as a function of the mass of their progenitor main-sequence stars M_ms from the abundance patterns of extremely metal-poor…
Classical novae are potential gamma-ray emitters, because of the disintegration of some radioactive nuclei synthesized during the explosion. Some short-lived isotopes (such as 13N and 18F), as well as the medium-lived 22Na, decay emitting…
Bulk meteorites and their inclusions exhibit, for many chemical elements, isotopic variability produced by nucleosynthetic events in stars and supernovae before the formation of the Sun. While the exact astrophysical origins of these…
Several pieces of evidence suggest that silicate grains in primitive meteorites are not interstellar grains but condensates formed in the early solar system. Moreover, the size distribution of matrix grains in chondrites implies that these…
Detecting molecular line emission from classical nova remnants has the potential of revealing information on the composition of the ejecta, in particular, it can deliver accurate isotopic ratios in the matter processed by a thermonuclear…
Carbon-rich meteorites, carbonaceous chondrites, contain many biologically relevant organic molecules and delivered prebiotic material to the young Earth. We present compound-specific carbon isotope data indicating that measured purine and…
Magnetars are regarded as the most magnetized neutron stars in the Universe. Aiming to unveil what kinds of stars and supernovae can create magnetars, we have performed a state-of-the-art spatially resolved spectroscopic X-ray study of the…
We have derived isotopic fractions of europium, samarium, and neodymium in two metal-poor giants with differing neutron-capture nucleosynthetic histories. These isotopic fractions were measured from new high resolution (R ~ 120,000), high…
Spitzer photometry and spectroscopy of the star HD69830 reveal an excess of emission relative to the stellar photosphere between 8 and 35 $\mu$m dominated by strong features attributable to crystalline silicates with an emitting surface…