球狀星團(tuán)Ruprecht 106

Like Sherlock Holmes’s magnifying glass, the NASA/ESA Hubble Space Telescope can peer into an astronomical mystery in search of clues. The enigma in question concerns the globular cluster Ruprecht 106, pictured here. Unlike most globular clusters, Ruprecht 106 may be what astronomers call a single population globular cluster. While the majority of stars in a globular cluster formed at approximately the same location and time, it turns out that almost all globular clusters contain at least two groups of stars with distinct chemical compositions. The newer stars will have a different chemical make-up that includes elements processed by their older, massive cluster companions. A tiny handful of globular clusters do not possess these multiple populations of stars, and Ruprecht 106 is a member of this enigmatic group.

Hubble captured this star-studded image using one of its most versatile instruments, the Advanced Camera for Surveys (ACS). Much like the stars in globular clusters, Hubble’s instruments also have distinct generations: ACS is a third-generation instrument which replaced the original Faint Object Camera in 2002. Some of Hubble’s other instruments have also gone through three iterations: The Wide Field Camera 3 replaced the Wide Field and Planetary Camera 2 (WFPC2) during the last servicing mission to Hubble. WFPC2 itself replaced the original Wide Field and Planetary Camera, which was installed on Hubble prior to its launch.

Astronauts on the space shuttle serviced Hubble in orbit a total of five times and were able to either upgrade aging equipment or replace instruments with newer, more capable versions. This high-tech tinkering in low Earth orbit has helped keep Hubble at the cutting edge of astronomy for more than three decades.

Like Sherlock Holmes’s magnifying glass, the NASA/ESA Hubble Space Telescope can peer into an astronomical mystery in search of clues. The enigma in question concerns the globular cluster Ruprecht 106, pictured here. Unlike most globular clusters, Ruprecht 106 may be what astronomers call a single population globular cluster. While the majority of stars in a globular cluster formed at approximately the same location and time, it turns out that almost all globular clusters contain at least two groups of stars with distinct chemical compositions. The newer stars will have a different chemical make-up that includes elements processed by their older, massive cluster companions. A tiny handful of globular clusters do not possess these multiple populations of stars, and Ruprecht 106 is a member of this enigmatic group.

Hubble captured this star-studded image using one of its most versatile instruments, the Advanced Camera for Surveys (ACS). Much like the stars in globular clusters, Hubble’s instruments also have distinct generations: ACS is a third-generation instrument which replaced the original Faint Object Camera in 2002. Some of Hubble’s other instruments have also gone through three iterations: The Wide Field Camera 3 replaced the Wide Field and Planetary Camera 2 (WFPC2) during the last servicing mission to Hubble. WFPC2 itself replaced the original Wide Field and Planetary Camera, which was installed on Hubble prior to its launch.

Astronauts on the space shuttle serviced Hubble in orbit a total of five times and were able to either upgrade aging equipment or replace instruments with newer, more capable versions. This high-tech tinkering in low Earth orbit has helped keep Hubble at the cutting edge of astronomy for more than three decades.

(from ESA)

就像夏洛克·福爾摩斯的放大鏡一樣，NASA/ESA的哈勃太空望遠(yuǎn)鏡可以窺視天文奧秘，尋找線索。這次所討論的謎團(tuán)與球狀星團(tuán)Ruprecht 106有關(guān)，如圖所示。與大多數(shù)球狀星團(tuán)不同，Ruprecht 106可能是天文學(xué)家所說的單一種群球狀星團(tuán)。雖然球狀星團(tuán)中的大多數(shù)恒星形成于大致相同的位置和時(shí)間，但事實(shí)證明，幾乎所有球狀星團(tuán)都包含至少兩組具有不同化學(xué)成分的恒星。較新的恒星將具有不同的化學(xué)組成，其中包括由其較老的大質(zhì)量星團(tuán)伴星處理過的元素。極少數(shù)球狀星團(tuán)并不擁有如此多的恒星群，Ruprecht 106就是這個(gè)神秘星團(tuán)的一員。

哈勃望遠(yuǎn)鏡使用其最通用的儀器之一——高級(jí)巡天相機(jī)（ACS）拍攝到了這張星圖。與球狀星團(tuán)中的恒星非常相似，哈勃的儀器也有不同的世代：ACS是第三代儀器，于2002年取代了原來的微弱物體照相機(jī)。哈勃的其他一些儀器也經(jīng)歷了三次迭代：在哈勃的最后一次維修任務(wù)中，廣角相機(jī)3號(hào)取代了廣角行星2號(hào)相機(jī)（WFPC2）。WFPC2本身取代了發(fā)射前安裝在哈勃望遠(yuǎn)鏡上的原始廣角和行星照相機(jī)。

航天飛機(jī)上的宇航員在軌道上總共為哈勃維修了五次，并能夠?qū)匣脑O(shè)備進(jìn)行升級(jí)，或者用更新、功能更強(qiáng)的版本替換儀器。這種在低地球軌道上進(jìn)行的高科技修補(bǔ)，幫助哈勃在30多年來一直處于天文學(xué)的前沿。