Big Changes 巨变

Amateur Astronomer - - 宇宙奥秘 - 特别说明:以上英文内容引自Stardate网站(https://stardate.org/),原文作者为Damond Benningfield,欢迎点击查看。

For most of a star’s long life, things happen slowly. A star like the Sun, for example, steadily converts hydrogen to helium in its core for about 10 billion years. At the end of that run, the pace picks up. And in the star’s final, colorful act, major changes can happen over just a few centuries.

在一颗恒星漫长一生的绝大部分时间,事情总是慢慢发生的。举例而言,一颗像太阳这样的恒星,要用大约100亿年稳定地将其内核中的氢转换为氦。在这个历程的最后阶段,脚步加快了。在恒星的最后阶段,色彩绚烂的行动,巨大的变化可能在仅仅几百年间发生。

One star that may be going through that last act is in Hydra, the water snake.

那条水蛇,长蛇座的一颗恒星可能将要上演这样的最后戏码。

V Hydra appears to consist of two stars. The main star is the same mass as the Sun. It’s at the very end of its life, though, so it’s puffed up to more than 400 times the Sun’s diameter. The star pulses in and out like a beating heart, and it’s ejecting a lot of gas into space.

长蛇座v像是由两颗恒星构成的。其主星与太阳质量相似。它正处于生命的最后阶段,因而它肿胀得有太阳直径的400倍。这颗星脉动起来宛如一颗跳动的心脏,并且它将大量的气体喷射到宇宙空间。

The second star orbits the bigger one every eight and a half years on a stretched-out path. When it gets close to the bigger star, it grabs some of the expelled gas, forming a disk. When enough gas builds up, some of it may be flung back into space as a “cannonball” — a blob that’s twice as heavy as the planet Mars.

第二颗恒星每八年半的时间就绕那颗较大的恒星在被拉长的轨道上运行一周。当它靠近较大的恒星时,它就获取一些喷射出的气体,形成圆盘。当有足够多的气体积聚起来,其中一些可能会如同投掷一颗“炸弹”一样被抛入宇宙空间,而这“炸弹”大约是行星火星重量的两倍。

So today, astronomers are seeing big changes in V Hydra every few years. And the changes could come even faster in the not-too-distant future. The bigger star may soon expel all of its outer layers of gas into space, forming a colorful nebula. The companion may sculpt it into an exotic shape — perhaps an hourglass, or even a butterfly. It’s a process that could play out very soon — a fast-paced change for a Sun-like star.

所以,如今天文学家们每隔几年就能目睹发生在长蛇座v上的巨变。这样的变化可能会在不远的将来发生得更快。那颗稍大的恒星可能会很快将它外层的全部气体驱逐到宇宙空间,形成一个色彩绚丽的星云。而它的同伴可能会把星云雕刻成独特的形状——可能是沙漏形,或者甚至会是蝴蝶形。这是一个能够很快完成的变化,是一颗类似太阳的恒星的快速变化。

上图是N G C 6302星云,也被称为蝴蝶星云。据估计,这颗行星状星云的表面温度约为25万摄氏度,它已变得异常炽热。而它舒展开的巨大翅膀大约跨越了3光年距离。已经发生巨变的长蛇座v会不会产生一个如N G C 6302一样的美丽星云呢?图片来源:版权所有N A S A , E S A , H ubble, HLA;后期处理版权Jesús M .Vargas &am p;M aritxu P oyal

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