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从垂死的恒星V Hydrae中形成一个协同的,高速的外流
1Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91109, USA. raghvendra.sahai@jpl.nasa.gov
Nature
|November 25, 2003
概括
天文学家发现了来自非对称巨型分支恒星V Hydrae的新喷气,为形成非球状行星星云至关重要的高速外流提供了直接证据. 这一发现支持了涉及伴星周围积聚盘的模型.
科学领域:
- 天文学和天体物理学.
- 恒星进化中的恒星演变
- 星球星云形成的过程
背景情况:
- 具有1-8太阳质量的恒星经历着不同的进化阶段.
- 非对称巨分支 (AGB) 恒星通过球形风喷射出相当大的质量.
- 转变为非球状行星星云的理解很少,最近的理论表明高速喷气起到了作用.
研究的目的:
- 提供从AGB恒星过渡到行星星云期间高速外流的直接观测证据.
- 为了研究喷气在行星星云形成中的作用.
- 测试涉及紧伴侣和积累盘的模型来驱动这些外流.
主要方法:
- 对附近的AGB恒星V Hydrae进行观测.
- 在新启动的喷气式外流中检测正确的运动.
- 随着时间的推移,监测外流的演变.
主要成果:
- 发现了一个新发射的,高速喷气式的外流从V Hydrae.
- 确认检测到的喷气中的正确运动和正在进行的演变.
- 确定一个中央的,密集的赤道圆盘状结构.
结论:
- 观测到的喷气提供了在恒星进化的后期阶段高速外流的直接证据.
- 这些发现支持模型,其中喷气是由围绕看不见的紧伴侣的积累盘驱动的.
- 赤道盘可能在使或增强积累盘形成和随后的喷气发射中发挥作用.
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