Related papers: A transmission electron microscopy study of presol…
We present 8--13 micron low resolution spectra (R~100) of 8 low-mass protostellar objects ("proplyds") in the Orion Nebula using the Long Wavelength Spectrometer (LWS) at the W. M. Keck Observatory. All but one of the sources in our sample…
Corundum ($\alpha$-Al$_{2}$O$_{3}$) and amorphous or metastable Al$_{2}$O$_{3}$ are common components of circumstellar dust observed around O-rich asymptotic giant branch (AGB) stars and found in primitive meteorites. We report a detailed…
We report NanoSIMS Si and Mg-Al isotopic data (and C, N, and Ti isotopic data when available) for 85 submicron- to micron-sized presolar SiC grains from the CM2 Murchison meteorite, including 60 MS, 8 AB1, 8 X, 7 AB2, and 2 Y grains. The MS…
Mainstream presolar SiC grains from primitive meteorites show a clear s-process signature in the isotopic composition of heavy trace elements. These grains most likely condensed in the winds of a variety of AGB stars. However, the non-solar…
We report C, N, Si, and Al-Mg isotope data for 39 presolar X silicon carbide (SiC) and four silicon nitride grains - a group of presolar grains that condensed in the remnants of core-collapse Type II supernovae (CCSNe) - isolated from the…
The chemical makeup of our solar system is a reflection of Galactic chemical evolution in the local interstellar medium (ISM) over the past ~9 Ga before the formation of the solar system. Although the incorporated ISM dust was mostly…
We report the identification of presolar silicates (~177 ppm), presolar oxides (~11 ppm), and one presolar SiO2 grain in the Allan Hills (ALHA) 77307 chondrite. Three grains having Si isotopic compositions similar to SiC X and Z grains were…
A new formation scenario for TiC and Fe,Ni-metal inclusions in presolar graphite grains of supernova origin is described. The mineralogy and chemistry require condensation of (Fe,Ni)-titanides from Fe, Ni, and Ti-rich gaseous ejecta,…
We report the discovery of five SiC grains and one graphite grain isolated from the Murchison carbonaceous meteorite whose major-element isotopic compositions indicate an origin in nova explosions. The grains are characterized by low…
We compute the concentrations of five transition elements (Cr, Fe, Co, Ni and Zn) in supernova presolar grains (Silicon Carbide Type X) from the time they condense till the end of free expansion phase, via condensation and implantation. We…
Presolar grains in meteorites and interplanetary dust particles (IDPs) carry non-solar isotopic signatures pointing to origins in supernovae, giant stars, and possibly other stellar sources. There have been suggestions that some of these…
We report trace element analyses by laser ablation inductively coupled plasma mass spectrometry of metal grains from 9 different CR chondrites, distinguishing grains from chondrule interior ("interior grains"), chondrule surficial shells…
Among presolar materials recovered in meteorites, abundant SiC and Al$_{2}$O$_{3}$ grains of AGB origins were found. They showed records of C, N, O, $^{26}$Al and s-element isotopic ratios that proved invaluable in constraining the…
Galactic chemical evolution (GCE) is important for understanding the composition of the present-day interstellar medium (ISM) and of our solar system. In this paper, we aim to track the GCE by using the 29Si/30Si ratios in evolved stars and…
The isotopic compositions of ruthenium (Ru) are measured from presolar silicon carbide (SiC) grains. In a popular scenario, the presolar SiC grains formed in the outskirt of an asymptotic giant branch (AGB) star, left the star as a stellar…
Evidence for similar chemical characteristics around low- and high-mass protostars has been found: in particular, a variety of carbon-chain species and complex organic molecules (COMs) are formed around them. On the other hand, the chemical…
About a year after core collapse supernova, dust starts to condense in the ejecta. In meteorites, a fraction of C-rich presolar grains (e.g., silicon carbide (SiC) grains of Type-X and low density graphites) are identified as relics of…
We have carried out high-angular resolution (1.4") observations in the continuum at 3.1mm and in the N2H+ 1-0, CH3CN 5_k-4_k and 13CS 2-1 lines using the Plateau de Bure Interferometer (PdBI) towards the intermediate mass (IM) protostar…
We report on the results of NanoSIMS isotope imaging of low-density supernova graphite grains from the Orgueil meteorite. 70 nm thick microtomed sections of three supernova graphite grains were deposited on Si wafers and isotopically imaged…
This review provides an introduction to presolar grains - preserved stardust from the interstellar molecular cloud from which our solar system formed - found in primitive meteorites. We describe the search for the presolar components, the…