Precise initial abundance of Niobium-92 in the Solar System and implications for p-process nucleosynthesis

Title	Precise initial abundance of Niobium-92 in the Solar System and implications for p-process nucleosynthesis
Authors	Makiko K. Haba, Yi-Jen Lai, Jörn-Frederik Wotzlaw, Akira Yamaguchi, Maria Lugaro, Maria Schönbächler
Magazine	Proceedings of the National Academy of Sciences
Date	02/19/2021
DOI	10.1073/pnas.2017750118
Introduction	The niobium-92–zirconium-92 (92Nb–92Zr) decay system, with a half-life of 37 million years, holds significant potential for dating planetary material evolution in the early Solar System. Understanding the initial abundance of the p-process isotope 92Nb is crucial for quantifying its role in astrophysical nucleosynthesis models. Present estimates of the initial 92Nb/93Nb ratios carry considerable uncertainties, hindering the use of the 92Nb–92Zr cosmochronometer and limiting nucleosynthetic model accuracy. This study achieves high precision in determining initial 92Nb abundance by integrating 92Nb–92Zr systematics of co-genetic rutiles and zircons from mesosiderites with U–Pb dating of the same zircons. The mineral pair analysis suggests that the Solar System began with a 92Nb/93Nb ratio of (1.66 ± 0.10) × 10−5, explained by a three-stage Nb–Zr evolution on the mesosiderite parent body. Enhanced precision by a factor of six reveals that the presence of 92Nb in the early Solar System indicates contributions from both type Ia and core-collapse supernovae to light p-process nuclei.
Quote	Makiko K. Haba, Yi-Jen Lai and Jörn-Frederik Wotzlaw et al. Precise initial abundance of Niobium-92 in the Solar System and implications for p-process nucleosynthesis. Proc Natl Acad Sci USA. 2021. Vol. 118(8):e2017750118. DOI: 10.1073/pnas.2017750118
Element	Niobium (Nb) , Zirconium (Zr)
Materials	Metals and Alloys
Industry	Research & Laboratory