哈勃在银河系的中心发现稀有蓝离散星

原文链接
http://www.nasa.gov/mission_pages/hubble/science/blue-straggler.html
NASA's Hubble Finds Rare 'Blue Straggler' Stars in Milky Way's Hub
05.25.11



NASA's Hubble Space Telescope has found a rare class of oddball stars called blue stragglers in the hub of our Milky Way, the first detected within our galaxy's bulge.

Blue stragglers are so named because they seemingly lag behind in the aging process, appearing younger than the population from which they formed. While they have been detected in many distant star clusters, and among nearby stars, they never have been seen inside the core of our galaxy.

It is not clear how blue stragglers form. A common theory is that they emerge from binary pairs. As the more massive star evolves and expands, the smaller star gains material from its companion. This stirs up hydrogen fuel and causes the growing star to undergo nuclear fusion at a faster rate. It burns hotter and bluer, like a massive young star.

                               
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The Hubble Telescope captures blue straggler stars in the Milky Way bulge Credit: NASA, ESA, W. Clarkson (Indiana University and UCLA), and K. Sahu (STScl)


The findings support the idea that the Milky Way's central bulge stopped making stars billions of years ago. It now is home to aging sun-like stars and cooler red dwarfs. Giant blue stars that once lived there have long since exploded as supernovae.

The results have been accepted for publication in an upcoming issue of The Astrophysical Journal. Lead author Will Clarkson of Indiana University in Bloomington, will discuss them today at the American Astronomical Society meeting in Boston.

"Although the Milky Way bulge is by far the closest galaxy bulge, several key aspects of its formation and subsequent evolution remain poorly understood," Clarkson said. "Many details of its star-formation history remain controversial. The extent of the blue straggler population detected provides two new constraints for models of the star-formation history of the bulge."

The discovery followed a seven-day survey in 2006 called the Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS). Hubble peered at 180,000 stars in the crowded central bulge of our galaxy, 26,000 light-years away. The survey was intended to find hot Jupiter-class planets that orbit very close to their stars. In doing so, the SWEEPS team also uncovered 42 oddball blue stars with brightness and temperatures typical for stars much younger than ordinary bulge stars.

The observations clearly indicate that if there is a young star population in the bulge, it is very small. It was not detected in the SWEEPS program. Blue stragglers long have been suspected to be living in the bulge, but had not been observed because younger stars in the disk of our galaxy lie along the line-of-sight to the core, confusing and contaminating the view.

Astronomers used Hubble to distinguish the motion of the core population from foreground stars in the Milky Way. Bulge stars orbit the galactic center at a different speed than foreground stars. Plotting their motion required returning to the SWEEPS target region with Hubble two years after the first observations were made. The blue stragglers were identified as moving along with the other stars in the bulge.

"The size of the field of view on the sky is roughly that of the thickness of a human fingernail held at arm's length, and within this region, Hubble sees about a quarter million stars toward the bulge," Clarkson said. "Only the superb image quality and stability of Hubble allowed us to make this measurement in such a crowded field."

From the 42 candidate blue stragglers, the investigators estimate 18 to 37 are likely genuine. The remainder could be a mix of foreground objects and, at most, a small population of genuinely young bulge stars.

"The SWEEPS program was designed to detect transiting planets through small light variations" said Kailash Sahu, the principal investigator of the SWEEPS program. "Therefore the program could easily detect the variability of binary pairs, which was crucial in confirming these are indeed blue stragglers."

Hubble is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington. For images and more information about the findings, visit:

http://www.nasa.gov/hubble
and
http://hubblesite.org/news/2011/16

                               
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这望远镜后面要多智能的计算机才能在满天的星星当中找到符合论文需要的星星？

全是E文..图看着眼花..
不过，还是多谢楼主分享~~

第一幅放大的图里圈住的都是什么东东!?

你可太快了，哈勃官网昨晚才发，我还一个字都没来得及翻译。

但是这种全英文不行啊，你先翻译个大概吧。

顺便问一下，这个是你的真名，你是女的？

我不是女生，名字嘛，你自己猜猜看吧

你可太快了，哈勃官网昨晚才发，我还一个字都没来得及翻译。

但是这种全英文不行啊，你先翻译个大概吧。 ...
gohomeman1 发表于 2011-5-27 20:54

                               
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    翻译就别指望我了，这种专业词汇较多的英文对我来说就是天书。
如果能找得到中文的我会尽量贴中文。

NASA的哈勃发现罕见的恒星周围的蓝色Straggler在银河系中心的地位

05.25.11




NASA的哈勃太空望远镜已经发现星星非常出色的怪胎叫作蓝色散兵游勇在我们的银河系的中心地带,第一个发现在我们的星系的优势。


蓝色的散兵游勇是这样命名是因为他们似乎落后在衰老的过程,出现以下的人口,他们从那里形成。虽然他们有被发现在许多遥远的恒星附近的恒星,并在集群,他们也从未见过我们的星系内的核心。


人们并不清楚蓝色散兵游勇形式。普遍接受的理论认为,他们来自于二进制配对。作为更大质量恒星的演进和扩展,小明星所得资料从它的伴侣。这煽起氢燃料及原因进行不断增长的星核融合的速度在加快。它燃烧更热、更蓝,就像一个巨大的年轻的恒星。
这些结果已经出版了在下期的《天体物理学杂志》上。首席作者将克拉克森的布卢明顿市的印第安纳大学,将会讨论他们今天在美国天文学会的会议在波士顿。


“虽然这个银河系是迄今为止最接近胀胀,几个关键方面星系的形成和随后的演化仍不了解,”克拉克森说道。“许多细节仍然是有争议的star-formation历史。蓝色的程度straggler检测提供了两种新的约束的人口为模型的star-formation历史的优势。”


为期七天的调查发现在2006年之后被称为人马座窗口吞噬在外太阳系行星搜索(扫)。哈勃细看180,000星星在拥挤的中央胀我们的星系,26000光年。这项调查的目的是找到热Jupiter-class行星轨道非常接近他们的球星。这样以来,研究团队也发现了42个怪胎清扫和温度的蓝色恒星和恒星亮度的典型比普通胀年轻得多的星星。


观测注明如果有一颗年轻恒星的人口,是非常小胀。它不能被探测到的清洁工的程序。蓝色的散兵游勇长一直怀疑是住在胀,但还未观察到磁盘,因为年轻恒星在我们的星系的视线,在路边等着核心,迷惑和污染的看法。


天文学家使用哈勃区分两种运动的核心人口从前景是银河系中星星。银河中心恒星轨道胀在不同速度比前景恒星。他们需要策划回到扫运动目标区域用哈伯太空望远镜两年后第一次进行了比较研究。蓝色的散兵游勇,分别鉴定为移动连同其他恒星的星系。


“大小的视野下,天空上大致厚度的一个人类指甲举到一臂的长度,以及在此区,哈勃所见大约有1 / 4百万恒星朝向鼓包,“克拉克森说道。“只有极佳的影像质量及稳定性的哈勃允许我们让这个测量在这样一个拥挤的领域。”


从42个候选人,调查人员估计蓝色散兵游勇18 - 37可能真品。其余的可能是一种混合的前景对象和,至多,一小群真正年轻胀的星星。


“扫计划的最终目的是通过一个小的光侦测凌日行星Sahu变奏曲”说,主要研究者底的清洁工的程序。“因此这个计划可能会很容易的察觉的可变性,二进制双至关重要,确认这实在是蓝色的散兵游勇。”


“哈勃”是一个国际合作与交流项目的美国国家航空和宇宙航行局与欧洲太空总署。美国国家航空航天局戈达德太空飞行中心的绿地,市经营的望远镜。太空望远镜科学研究所(STScI哈勃科学)进行操作。美国国家航空和宇宙航行局STScI是进行手术,由大学天文研究协会在华盛顿。对于图像和更多的信息是关于这些发现,游览:
小小的翻译

回复 9# cuicanxingkong

机器翻译的？看了只能等到下周了。

回复 4# 越过日夕

就是那些蓝离散星所在的位置，它们是两颗类太阳恒星合并产生，或者密近双星中一颗红巨星（注意一般不是红超巨星）的外层转移到另一个主序星后形成。

看不太懂……只能抱着欣赏的心态了