本帖最后由 meteorobs 于 2010-12-25 22:35 编辑
发信人: thesuby (好，大家都改4时间了), 信区: SF
标 题: 转载：燃烧的星星
发信站: 水木社区 (Wed Dec 15 11:08:46 2010), 站内
燃烧着的合并过程中的星星
Mon Dec 13, 2010 12:04 PM ET
2010.12.13. 周一， 12:04 PM ET
In 2002, astronomers witnessed one of the strangest celestial events ever. A star on the outskirts of our Milky Way briefly grew one million times brighter, outshining almost all other stars in our galaxy. It didn’t explode as a supernova, but just sort of hiccuped a brilliant burst of light.
2002年，天文学家见证了史上最奇怪的天文现象之一。银河系的外围的一颗恒星一下子变得比原来亮100万倍，银河系其他的恒星几乎都黯然失色。它并没有爆炸成超新星，只是一次能量的突然释放。
The star, called V838 Monocerotis, expanded to an enormous size, cooled and reddened (above). Since then razor-sharp Hubble Space Telescope pictures have caught the eerie "light echo" around the star as the glow from the flash rebounds off of interstellar dust. This phenomenon gives the illusion that material is streaming off the star as velocities faster than the speed of light.
这颗名为V838 莫诺塞若蒂斯的恒星，体积膨胀到巨大，冷却后泛着红光（见上图）。高分辨率的哈勃太空望远镜拍摄的照片捕捉到闪烁的光亮从星际的尘埃反射回来时星体周围产生的怪异的“回光”。这一现象不禁使人们误认为当速度大于光速时物质从星体里涌流出来。
Astronomers remain at a loss to satisfactorily explain the outburst, but there has been lots of speculation. Did the star ignite helium at the core, swallow a planet, or swallow a companion star?
虽然仍然无法对这一爆发做出满意的解释，但天文学者还是做了许多推测。星体燃烧了核内的氦，吞并了行星或伴星吗？
In September 2008, another strange stellar burst was seen deep in the heart of the Milky Way, 10,000 light-years away in the opposite direction of V838 Mon.
2008年9月，人们在银河系中心深处距离V838 莫诺塞若蒂斯一万光年的地方观测到另一个奇怪的恒星爆炸现象。
Called V1309 Scorpii, it too would have joined the "stellar weirdo" list if not for a fortuitous observation that caught the pre-disaster activity -- like a shopping mall security camera recording a crime from start to finish.
这颗星星叫V1309 Scorpi。要不是被抓拍下灾难发生前的活动，它也会被列入“恒星怪胎”的名单，就像商场的摄像头记录下犯罪全过程一样。
Our galactic surveillance camera is the nearly two decade-long Optical Gravitational Lensing Experiment (OGLE), that looks for small changes in the brightness of tens of millions of stars in the direction of the galactic center.
我们的银河观测摄像机，就是可见光重力透镜实验，已经有将近20年的历史了。它沿着银河系中心的方向监测千百万只恒星的亮度的微小变化。
A major goal of the project is to capture gravitational microlensing events where an unseen body passes between a background star and Earth. This causes the background star to momentarily brighten as the gravitational field of the foreground object amplifies the starlight like a magnifying glass. Light changes can also be caused by intrinsically variable stars, and planets passing in front of stars.
这一项目的主要目标是，捕获重力微引力透镜效应，看不见的星体在背景星和地球之间穿过。这使得当前景物体的重力场如放大镜一样将星光放大时背景星瞬间变亮。内部可变的星和从它们前面经过的行星之间，也能产生这种光亮的变化。
From 2001 to 2008 the OGLE survey made over 1,300 observations of the orange dwarf star before it blew its top in 2008. The star just happened to be in the field of view.
2001年至2008年间，在黄矮星爆炸之前，可见光重力透镜实验项目组对其进行过1300次的观察。这颗星恰巧就在视场范围内。
The survey shows that the star oscillated in brightness for years before the brilliant flash. Mysteriously the oscillation period was first measured at 1.4 days but grew shorter leading up to the 2008 blowout.
测勘结果表明，它在出现明亮闪光之前的数年里，一直经历了亮度变化。神奇的是，它的变化周期第一次测得为1.4天，但是在2008年爆炸之前却变短了。
It's unlikely the variability could have been caused by star spots coming and going. A 1.4-day period would not remain so stable for so long. Like sunspots, starspots should change in size and migrate. It's also unlikely the star was pulsating because the oscillation rate got shorter over a several year period.
这种变化不大可能是由恒星黑子的来来回回所导致。1.4天的变化周期不会长时间维持不变。如太阳黑子，恒星黑子大小会变会移动。同样不大可能的是，恒星因为摆动速率数年之后变短而振动。
The best explanation is that actually two stars were seen orbiting edge-on to our line of sight. The amount of light from the system would momentarily drop every time one star passed behind the other. If the stars were spiraling together the orbital period would shorten, as observed.
The fast orbit meant that double star system was an unusual "contact binary" where a pair of stars are so close together they are nearly touching each other and share a common coronal envelope -- like a pair of waltzing skaters whirling around each other rapidly. Friction between the two stars would put drag on the system, and rob orbital momentum, causing the stars to get closer to each other.
最合理的解释是，我们看到的两颗星在视线侧面绕轨道运行。每次其中一颗星从另一颗的背后经过时整体发出的光亮度就会瞬间下降。正如所观察的那样，两颗星一起盘旋时轨道 周期将会变短。
快速轨道运动意味着，双星系统是一对不寻常的密接双星，此时两颗星如此接近以至于它们几乎可以碰到彼此而共用一个日冕包络，就像一对华尔兹滑冰者围绕彼此快速旋转。双星之间的摩擦对系统产生阻力，轨道角动量减小，使得两颗星靠得更近。
When the stars merged all hell broke loose. The momentum from the orbit was converted to heat, causing the new merged star to skyrocket in temperature. The star also suddenly grew 10,000 times brighter.
星星合并之时，爆炸便发生了。轨道角动量转换成热量，导致合并成的星星迅速升温。它的亮度也突然增大一万倍。
Imagine for a moment that the contact binary had an inhabited planet with an advanced civilization. Its astronomers would have noted the shortening orbital period between the binary duo.
想象一下，假如密接双星有一颗居住着拥有先进文明的人类的行星，行星上的天文学者将会注意到两个星星之间的轨道周期变短。
This would presage a true apocalypse for the civilization. Anticipation would be reminiscent of today's "2012" silly doomsday hysteria, except this would be for real. Astronomers would realize that the inevitable merger would incinerate the surface of their planet, perhaps boil away its oceans, and strip away the atmosphere. They would have a real doomsday clock the counted down each shrinkage of the binary’s orbital period.
这将预示这个文明的实在的灭顶之灾。这将让人想起如今的2012的末日到来的荒唐预言，除非这是真的。天文家们将意识到，这种不可避免的星体合并现象将烧毁他们的行星表面，很可能蒸发掉海洋，去除大气层。他们将真的会记录下双体的轨道周期每次的缩短，倒数着末日到来的日子。
ANALYSIS: Why Does a Star Explode?
分析：为什么恒星会爆炸？
A space ark with a small population of refuges might be dispatched to find shelter on a moon of one of the system’s gas giant outer planets. That is, assuming the merged star did swell up big enough to devour the entire system, as V838 Mon has done.
载着少量难民的太空方舟，被派往银河系的一颗巨大的气体外行星的卫星上寻找避难所。假设合并成的星星确实膨胀到足够大以吞食整个系统，正如V838那样。
At the right distance, they would be in a newly expanded habitable zone around the swelled-up star.
在恰当的距离处，他们将处于鼓胀起来的星星周围的体积变大的可居住的地带。
The civilization's political and social upheaval would be unimaginably severe because only a fraction of the global population of planet could be saved. Independent nations would embark on a technological "survival-race" to see how many citizens could be launched off the planet. The 1933 science fiction novel "When Worlds Collide," presents just such a scenario.
文明国家的政治和社会将发生难以想象的严峻的剧变，因为地球人口中只有极少一部分人能获救。独立国家将开始一场技术“生存竞赛”，较量一下到底能让多少人撤离地球。1933年的科幻小说，“当世界毁灭时”，就是这样的剧情。
Those left on the doomed planet might gamble to set up survival habitats in deep underground caverns with air, water and food processing capabilities.
那些留在地球上的人，可能要冒险在地底深处建立起洞穴以供生存，洞穴内有处理空气、水、食物的能力。
This is also reminiscent of the projection of a post-nuclear holocaust underground shelters envision in the 1964 dark-comedy film, "Dr. Strangelove":
这同样让人想起1964年的暗喜剧电影《斯坦洛夫博士》里描述的核后大屠杀地下避难所入侵：
U.S. President: “Well I... I would hate to have to decide.. who stays up and.. who goes down.”
美国总统：“额，我讨厌做决定……决定谁上升谁下降。”
Dr. Strangelove: “ . . .a computer could be set and programmed to accept factors from youth, health, sexual fertility, intelligence, and a cross section of necessary skills. Of course it would be absolutely vital that our top government and military men be included to foster and impart the required principles of leadership and tradition.” |
置顶卡
变色卡
千斤顶
显身卡
