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Detección directa del efecto YORP del asteroide.
Stephen C Lowry1, Alan Fitzsimmons, Petr Pravec
1School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK. s.c.lowry@qub.ac.uk
Science (New York, N.Y.)
|March 10, 2007
Resumen
El efecto Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) proporciona evidencia directa de la alteración de las velocidades de giro de los asteroides. Las observaciones precisas del asteroide cercano a la Tierra 2000 PH5 muestran un aumento continuo en su rotación, lo que confirma el efecto YORP.
Área de la Ciencia:
- Dinámica del sistema solar Dinámica del sistema solar
- Física de los asteroides Física de los asteroides
- La astronomía observacional es la astronomía de las observaciones.
Sus antecedentes:
- El efecto Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) es un mecanismo teorizado que influye en la rotación de los pequeños cuerpos del sistema solar.
- La evidencia previa para el efecto YORP ha sido indirecta, faltando pruebas observacionales definitivas.
Objetivo del estudio:
- Proporcionar evidencia observacional directa de la influencia del efecto YORP en los estados de giro de los asteroides.
- Para medir con precisión el cambio en la velocidad de giro de un pequeño asteroide cercano a la Tierra.
Principales métodos:
- Realizó observaciones fotométricas ópticas precisas del asteroide (54509) 2000 PH5 durante un período de 4 años.
- Analizaron datos de observación para determinar la velocidad de rotación del asteroide y su cambio con el tiempo.
- Realizó simulaciones dinámicas, incluido el análisis del par gravitatorio y el modelado de aproximación cercana a la Tierra, para descartar explicaciones alternativas.
Principales resultados:
- Se observó un aumento continuo en la velocidad de rotación del asteroide 2000 PH5.5.
- Cuantificó el aumento de la velocidad de giro como domega/dt = 2.0 (+/-0.2) x 10(-4) grados por día al cuadrado.
- Demostró que los torques gravitacionales de los encuentros con la Tierra no podían explicar la aceleración de espín observada.
Conclusiones:
- El aumento de la velocidad de giro observado en el asteroide 2000 PH5 proporciona evidencia directa del efecto YORP.
- Las simulaciones dinámicas apoyan el efecto YORP como la causa del cambio de giro.
- Se proyecta que el asteroide 2000 PH5 puede alcanzar un período de rotación de aproximadamente 20 segundos en el futuro.
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