The plausible source(s) of26Al in the early solar system: A massive star or the X-wind irradiation scenario?

AbstractWe discuss possible stellar origins of short-lived radioactive nuclei with meanlife τ ≤ 100 Myr, which were shown to be alive in the Early Solar System (ESS). We first review current ideas on the production of nuclides having 10 ≤ τ ≤ 100 Myr, which presumably derive from the continuous interplay of galactic astration, nucleosynthesis from massive supernovae and free decay in the interstellar medium. The abundance of the shorter lived 53Mn might be explained by this same scenario. Then we consider the nuclei 107Pd, 26Al, 41Ca and 60Fe, whose early solar system abundances are too high to have originated in this way. Present evidence favours a stellar origin, particularly for 107Pd, 26Al and 60Fe, rather than an in situ production by energetic solar particles. The idea of an encounter (rather close in time and space) between the forming Sun and a dying star is therefore discussed: this star may or may not have also triggered the solar formation. Recent nucleosynthesis calculations for the yields of the relevant short-lived isotopes and of their stable reference nuclei are discussed. Massive stars evolving to type II supernovae (either leaving a neutron star or a black hole as a remnant) seem incapable of explaining the four most critical ESS radioactivities in their observed abundance ratios. An asymptotic giant branch (AGB) star seems to be a viable source, especially if of relatively low initial mass (M ≤ 3 M⊙) and with low neutron exposure: this model can provide a solution for 26Al, 41Ca and 107Pd, with important contributions to 60Fe, which are inside the present uncertainty range of the 60Fe early solar system abundance. Such a model requires that 26Al is produced substantially on the AGB by cool bottom processing. The remaining inventory of short-lived species in the solar nebula would then be attributed to the continuous galactic processing, with the exception of 10Be, which must reflect production by later proton bombardment at a low level during early solar history.

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Proton-associated alpha-irradiation in the early solar system - A possible K-41 anomaly

The Astrophysical Journal ◽

10.1086/156108 ◽

1978 ◽

Vol 221 ◽

pp. 1026 ◽

Cited By ~ 4

Author(s):

E. Dwek

Keyword(s):

Solar System ◽

Early Solar System ◽

System A ◽

Alpha Irradiation ◽

K 41

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The Mg/Fe ratio of silicate minerals in the meteoritic materials and in the circumstellar environment: A case study for the chondritic-like composition

Open Astronomy ◽

10.1515/astro-2021-0006 ◽

2021 ◽

Vol 30 (1) ◽

pp. 45-55

Author(s):

Péter Futó ◽

József Vanyó ◽

Irakli Simonia ◽

János Sztakovics ◽

Mihály Nagy ◽

...

Keyword(s):

Solar System ◽

Crystallization Process ◽

Planet Formation ◽

Methodological Approach ◽

Optical Microscope ◽

Protoplanetary Disk ◽

Early Solar System ◽

System A ◽

Circumstellar Environment

Abstract Kaba meteorite as a reference material (one of a least metamorphosed and most primitive carbonaceous chondrites fell on Earth) was chosen for this study providing an adequate background for study of the protoplanetary disk or even the crystallization processes of the Early Solar System. Its olivine minerals (forsterite and fayalite) and their Mg/Fe ratio can help us to understand more about the planet formation mechanism and whether or not the metallic constitutes of the disk could be precursors for the type of planets in the Solar System. A multiple methodological approach such as a combination of the scanning electron microscope, optical microscope, Raman spectroscopy and electron microprobe of the olivine grains give the Fe/Mg ratio database. The analyses above confirmed that planet formation in the protoplanetary disk is driven by the mineralogical precursors of the crystallization process. On the other hand, four nebulae mentioned in this study provide the astronomical data confirming that the planet formation in the protoplanetary disk is dominated or even driven by the metallic constituents.

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26Aluminum from Massive Binary Stars. II. Rotating Single Stars Up to Core Collapse and Their Impact on the Early Solar System

The Astrophysical Journal ◽

10.3847/1538-4357/ac25ea ◽

2021 ◽

Vol 923 (1) ◽

pp. 47

Author(s):

Hannah E. Brinkman ◽

J. W. den Hartogh ◽

C. L. Doherty ◽

M. Pignatari ◽

M. Lugaro

Keyword(s):

Stable Isotopes ◽

Solar System ◽

Binary Stars ◽

Massive Star ◽

Radioactive Isotopes ◽

Core Collapse ◽

Early Solar System ◽

Wind Model ◽

Solar Metallicity ◽

Massive Models

Abstract Radioactive nuclei were present in the early solar system (ESS), as inferred from analysis of meteorites. Many are produced in massive stars, either during their lives or their final explosions. In the first paper of this series (Brinkman et al. 2019), we focused on the production of 26Al in massive binaries. Here, we focus on the production of another two short-lived radioactive nuclei, 36Cl and 41Ca, and the comparison to the ESS data. We used the MESA stellar evolution code with an extended nuclear network and computed massive (10–80 M ⊙), rotating (with initial velocities of 150 and 300 km s−1) and nonrotating single stars at solar metallicity (Z = 0.014) up to the onset of core collapse. We present the wind yields for the radioactive isotopes 26Al, 36Cl, and 41Ca, and the stable isotopes 19F and 22Ne. In relation to the stable isotopes, we find that only the most massive models, ≥60 and ≥40 M ⊙ give positive 19F and 22Ne yields, respectively, depending on the initial rotation rate. In relation to the radioactive isotopes, we find that the ESS abundances of 26Al and 41Ca can be matched with by models with initial masses ≥40 M ⊙, while 36Cl is matched only by our most massive models, ≥60 M ⊙. 60Fe is not significantly produced by any wind model, as required by the observations. Therefore, massive star winds are a favored candidate for the origin of the very short-lived 26Al, 36Cl, and 41Ca in the ESS.

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