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Gases nobles en el meteorito Murchison: Posibles reliquias del proceso s de nucleosíntesis
Science (New York, N.Y.)
|July 7, 1978
Resumen
Los meteoritos primitivos contienen granos de polvo presolar de gigantes rojas, evidenciados por patrones únicos de isótopos de xenón. Estos hallazgos sugieren que los procesos nucleares específicos ocurrieron en las estrellas evolucionadas antes de la formación del sistema solar.
Área de la Ciencia:
- Cosmoquímica es la cosmoquímica.
- La astrofísica nuclear es una astrofísica nuclear.
- Ciencias planetarias Ciencias planetarias.
Sus antecedentes:
- Las condritas carbonáceas, como el meteorito Murchison, son materiales primitivos del sistema solar.
- Las anomalías del isótopo de xenón en los meteoritos pueden proporcionar información sobre la nucleosíntesis presolar.
- Estudios anteriores han identificado varios componentes presolares en los meteoritos.
Objetivo del estudio:
- Para identificar y caracterizar un nuevo componente isotópico de xenón en el meteorito Murchison.
- Para investigar el origen de los enriquecimientos anómalos de isótopos de gases nobles.
- Para vincular estas anomalías a procesos específicos de nucleosíntesis estelar.
Principales métodos:
- Análisis de gases nobles de una fracción mineral específica del meteorito Murchison.
- Experimentos de calentamiento escalonado a alta temperatura para liberar gases atrapados.
- Análisis isotópico de xenón, criptón, neón y helio.
Principales resultados:
- Descubrimiento de un nuevo componente de xenón enriquecido en los isótopos 128-132.
- Identificación de enriquecimientos similares, aunque más pequeños, en los isótopos de criptón 80 y 82.
- Enriquecimientos anómalos observados en el neón-22 y el helio-3, liberados simultáneamente.
Conclusiones:
- Los patrones isotópicos observados sugieren fuertemente orígenes de la nucleosíntesis estelar, específicamente el proceso s y la quema de la cáscara de helio/hidrógeno en las gigantes rojas.
- Esto indica la presencia de granos de polvo presolar expulsados de estrellas gigantes rojas dentro de meteoritos primitivos.
- Estos hallazgos contribuyen a comprender la diversidad de los materiales presolares y la evolución química temprana del sistema solar.
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