QQ登录

只需一步,快速开始

谢克瑞云球

[复制链接]
zheng123 发表于 2008-12-28 12:43 | 显示全部楼层 |阅读模式 来自: 中国–上海–上海 电信
提示: 作者被禁止或删除 内容自动屏蔽
tyrealgtx 发表于 2008-12-28 13:54 | 显示全部楼层 来自: 中国–上海–上海 电信
本还以为是天空里云彩形成一个球球呢
回复 顶~ 砸~

使用道具 举报

q5968661 发表于 2008-12-28 15:15 | 显示全部楼层 来自: 中国–福建–厦门 电信
ABOUT THIS IMAGE:

Strangely glowing dark clouds float serenely in this remarkable and beautiful image taken with NASA's Hubble Space Telescope. These dense, opaque dust clouds - known as "globules" - are silhouetted against nearby bright stars in the busy star-forming region, IC 2944. These globules were first found in IC 2944 by astronomer A.D. Thackeray in 1950.

Although globules like these have been known since Dutch-American astronomer Bart Bok first drew attention to such objects in 1947, little is still known about their origin and nature, except that they are generally associated with areas of star formation, called "HII regions" due to the presence of hydrogen gas.

The largest of the globules in this image is actually two separate clouds that gently overlap along our line of sight. Each cloud is nearly 1.4 light-years (50 arcseconds) along its longest dimension, and collectively, they contain enough material to equal over 15 solar masses. IC 2944, the surrounding HII region, is filled with gas and dust that is illuminated and heated by a loose cluster of O-type stars. These stars are much hotter and much more massive than our Sun. IC 2944 is relatively close by, located only 5900 light-years (1800 parsecs) away in the constellation Centaurus.

Thanks to the remarkable resolution offered by the Hubble Space Telescope, astronomers can for the first time study the intricate structure of these globules. The globules appear to be heavily fractured, as if major forces were tearing them apart. When radio astronomers observed the faint hiss of molecules within the globules, they realized that the globules are actually in constant, churning motion, moving supersonically among each other. This may be caused by the powerful ultraviolet radiation from the luminous, massive stars, which also heat up the gas in the HII region, causing it to expand and stream against the globules, leading to their destruction. Despite their serene appearance, the globules may actually be likened to clumps of butter put onto a red-hot pan.

It is likely that the globules are dense clumps of gas and dust that existed before the massive O-stars were born. But once these luminous stars began to irradiate and destroy their surroundings, the clumps became visible when their less dense surroundings were eroded away, thus exposing them to the full brunt of the ultraviolet radiation and the expanding HII region. The new images catch a glimpse of the process of destruction. Had the appearance of the luminous O-stars been a bit delayed, it is likely that the clumps would actually have collapsed to form several more low-mass stars like the Sun. Instead they are now being toasted and torn apart.

The hydrogen-emission image that clearly shows the outline of the dark globules was taken in February 1999 with Hubble's Wide Field Planetary Camera 2 (WFPC2) by Bo Reipurth (University of Hawaii) and collaborators. Additional broadband images that helped to establish the true color of the stars in the field were taken by the Hubble Heritage Team in February 2001. The composite result is a four-color image of the red, green, blue and H-alpha filters.

from:hubblesite
回复 顶~ 砸~

使用道具 举报

白羊星座 发表于 2008-12-28 15:35 | 显示全部楼层 来自: 中国–甘肃–兰州 电信
好贴!!O(∩_∩)O哈哈~
回复 顶~ 砸~

使用道具 举报

霓虹彩云 发表于 2008-12-29 14:15 | 显示全部楼层 来自: 中国–上海–上海–杨浦区 电信
南非天文学家谢克瑞可真伟大。
回复 顶~ 砸~

使用道具 举报

本版积分规则

APP下載|手机版|爱牧夫天文淘宝店|牧夫天文网 ( 公安备案号21021102000967 )|网站地图|辽ICP备19018387号

GMT+8, 2024-12-26 00:03 , Processed in 0.137528 second(s), 24 queries , Gzip On, Redis On.

Powered by Discuz! X3.5 Licensed

Copyright © 2001-2020, Tencent Cloud.

快速回复 返回顶部 返回列表