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No hay dinamo similar al Sol en la estrella activa ζ Andrómedae debido a la asimetría de las manchas estelares
R M Roettenbacher1, J D Monnier1, H Korhonen2,3
1Department of Astronomy, University of Michigan, Ann Arbor, Michigan 48109, USA.
Nature
|May 5, 2016
Resumen
La actividad de las manchas estelares en ζ Andrómeda revela asimetrías globales, que desafían las teorías de la dínamo solar. Se observaron manchas polares, pero las manchas de menor latitud eran transitorias, lo que indica un comportamiento único del campo magnético estelar.
Área de la Ciencia:
- Astrofísica estelar
- Magnetohidrodinámica
- Ciencia de los exoplanetas
Sus antecedentes:
- Las manchas estelares son regiones más frías en las superficies estelares causadas por fuertes campos magnéticos.
- La actividad magnética influye en la estructura atmosférica estelar, afectando las estimaciones de masa y edad.
- La distribución norte-sur de las latitudes activas de las manchas estelares es clave para comprender las dinamos estelares.
Objetivo del estudio:
- Para obtener una imagen de la distribución de manchas estelares en la estrella magnéticamente activa ζ Andromedae.
- Para investigar la simetría norte-sur de la actividad de las manchas estelares.
- Para probar la validez de los modelos de dínamo de tipo solar para otras estrellas.
Principales métodos:
- Se utilizó interferometría infrarroja de larga línea de base para imágenes de alta resolución.
- Las observaciones se llevaron a cabo en dos épocas distintas para rastrear la evolución puntual.
- Las limitaciones de las imágenes Doppler se abordaron mediante el uso de interferometría.
Principales resultados:
- Se observaron manchas polares oscuras persistentes en ζ Andrómeda en ambas épocas.
- Las características de las manchas estelares de latitudes más bajas fueron transitorias y no persistieron entre las observaciones.
- Se detectaron asimetrías de manchas estelares globales significativas, que carecen de simetría norte-sur similar a la solar.
Conclusiones:
- ζ Andrómeda exhibe patrones de manchas estelares globales inconsistentes con la teoría del dínamo de tipo solar.
- Las asimetrías observadas sugieren mecanismos alternativos que impulsan la actividad magnética estelar.
- Las manchas polares pueden ser características genuinas, no artefactos de observación, en estrellas activas.
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