¿Miles de millones de nuevas vecinas?
La definición de los objetos que los astrónomos llaman enanas marrones está en algún lugar entre la de planeta y la de estrella. Son bolas de gas con más masa que un planeta, pero no lo suficientemente masivas como para mantener de forma estable la fusión del hidrógeno, como hacen las estrellas. Dado que apenas emiten luz visible, no fueron descubiertas hasta 1995 y, hasta hoy, la mayoría de las enanas marrones conocidas estaban a 1.500 años luz de nosotros.
Ahora, un equipo de astrónomos que ha utilizado la cámara infrarroja de óptica adaptativa NACO, instalada en el VLT (Very Large Telescope) de ESO, ha observado el cúmulo estelar RCW 38 en la constelación de la Vela, a unos 5.500 años luz de distancia. Esta imagen de la semana muestra la parte central de RCW 38; los insertos en los lados muestran un subconjunto de candidatas a enana marrón detectado dentro del cúmulo.
Los científicos descubrieron que alrededor de un tercio de las estrellas del cúmulo son enanas marrones. De estos resultados, y estudiando otros cúmulos de estrellas, los astrónomos estiman que la Vía Láctea contiene, al menos, entre 25 y 100 mil millones de enanas marrones. Probablemente RCW 38 contiene enanas marrones aún menos masivas y más tenues, estrellas que están más allá de los límites de detección de esta imagen, por lo que este nuevo cálculo podría ser realmente una subestimación significativa. Ulteriores sondeos revelarán el verdadero número de enanas marrones que acechan en la Vía Láctea.
Enlace:
Crédito:ESO/Koraljka Muzic (University of Lisbon), Aleks Scholz (University of St Andrews), Rainer Schoedel (Instituto de Astrofísica de Andalucía), Vincent Geers (UKATC), Ray Jayawardhana (York University), Joana Ascenso (University of Porto & University of Lisbon) & Lucas Cieza (University Diego Portales)
Sobre la imagen
| Identificador: | potw1729a |
| Idioma: | es |
| Tipo: | Collage |
| Fecha de publicación: | 17 de Julio de 2017 a las 06:00 |
| Tamaño: | 1414 x 1032 px |
Sobre el objeto
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