Sculptor Galaxy 玉夫星系 (14/5/2003)
玉夫星系，編號為NGC 253，是一個我幾喜歡的星系，今次這張相是由「加拿大．法國．夏威夷望遠鏡」影回來的（我記得第一次聽這個名時，都覺得非常奇怪），這個星系傾斜得很，看上去扁肩扁的，很特別。我們的銀河系加上附近一些星系合稱為本星系群，是宇宙中的一種結構，位於玉夫座方向的NGC253，跟我們距離一千萬光年，很近我們的本星系群（在天文上，一千萬也不算得什麼）。

Caption:: NGC 253, the Sculptor Galaxy, is a spiral galaxy located 10 million light years away from our galaxy. It exhibits a very high star formation rate and ranks as the brightest nearby galaxy outside our local group. This galaxy is indeed extremely rich in star fuel: the gas and dust that gives the disk a rather dully appearancel The spiral arms are the stellar nurseries and these are traced by lines of luminous young blue stars, like "beads on a string" according to Edwin Huble who pioneered the study of galaxies.

Credit:: Jean-Charles Cuillandre (CFHT) and CFHT

Colliding Black Holes 黑洞相撞 (13/5/2003)
平時大家聽到的甚麼又發現到一個黑洞的消息，其實都是誇大的，那些黑洞全部都是「懷疑」黑洞，因為用來觀測黑洞的全都是依賴間接的方法，除了那些位於星系核心的特大質量黑洞外，至今的理論仍未能100%分辨出那天體是黑洞還是另一些怪異天體。要觀測黑洞是這麼困難，那麼要看到黑洞相撞就更困難嗎？也倒不是，由於黑洞相撞時會釋出大量的重力波，若果我們能夠探測到這些重力波就可以找到黑洞了。這圖是一張電腦模擬黑洞相撞時釋出重力波的情況。

Caption:: I think you may have heard some news about scientists have found black holes, well indeed it may be a little bit exaggerated. Those are only black hole candidates, even until nowadays, astronomers have no confidence that those objects are really 100% black holes but not other exotic objects (except those supermassive black holes). So, will it be even more difficult for us to see them to collide? Well, it may not be. Black holes emit strong gravitational waves when they collide, we can detect it via gravitational wave detector once it is at function. This pic is a computer simulation of black hole collision with gravitational wave emitted.

Credit:: AEI and W. Benger

Cheetahs 獵豹 (12/5/2003)
碰上母親節的日子，送上一張和諧的獵豹母子相片給大家。提起獵豹，比較多聯想到牠們在非洲的大草原上馳騁覓食，但牠們也有和諧的一面，相中年幼的獵豹正在向媽媽撒嬌呢∼獵豹媽媽跟世界上所有的媽媽一樣（包括了動物和我們的母親），為兒子的溫飽四出奔跑，有時食物不足時，自己無得食也要給孩子食，人是如此動物也如此，或許這就是母親的天性。

Caption:: Cubs spend about 18 months with their mothers learning how to survive, and it may take them another year or two to become good hunters. They often start out chasing wildly inappropriate prey, including buffalo. ... Most females ... rear fewer than two individual cubs to independence in an average lifetime of seven years.

Credit:: Chris Johns

Helix Nebula 螺旋星雲 (11/5/2003)
又是一張哈勃太空望遠鏡的新相，說真的，我的確很喜歡哈勃拍回來的相，他始終都是一台位於太空的望遠鏡，早前裝了新相機，效果更是一流。今次這張相的原稿，是我見過解像度最高的相，有16000x16000像素！或許有機會的話，也跟上次一樣跟大家放大中間某部份。螺旋星雲位於寶瓶座，是一個很受歡迎的行星狀星雲，用雙筒望遠鏡也可以看到。順帶一提，這張相是哈勃在02年獅子座流星雨時影的，因為壯麗的流星雨，實質上都是太空的垃圾，一旦被他們擊中，望遠鏡會損毀嚴重，甚至有性命危險，所以那時便特地避開流星雨體，恰巧便用了長相間對準了相反方向的螺旋星雲，促成了這張極高解像度的相片。

Caption:: This photograph of the coil-shaped Helix Nebula is one of the largest and most detailed celestial images ever made. The composite picture is a seamless blend of ultra-sharp images from NASA's Hubble Space Telescope combined with the wide view of the Mosaic Camera on the National Science Foundation's 0.9-meter telescope at Kitt Peak National Observatory near Tucson, Ariz. The image shows a fine web of filamentary "bicycle-spoke" features embedded in the colorful red and blue ring of gas. At 650 light-years away, the Helix is one of the nearest planetary nebulae to Earth. A planetary nebula is the glowing gas around a dying, Sun-like star.

Credit:: NASA, NOAO, ESA, the Hubble Helix Nebula Team, M. Meixner (STScI), and T.A. Rector (NRAO)

Andromeda Halo Details 仙女座大星系銀暈(放大) (10/5/2003)
將昨日介紹過的仙女座大系銀暈的部份位置放大，可以見到很多不同形狀，不同顏色，不同大小的天體。銀暈是一個星系最外圍的地方，就咁看起來，甚麼東西也沒有，比起星系的圓盤或核球部份有著千萬計的恆星，真的相差太遠。然而，銀暈並非如此的真空，除了一般的星系際氣體，間中也有一些恆星；但除了恆星外，在他們背後很遠很遠的地方也有些背景佈置，就是大家現在看到的星系，由於他們很遠很遠，離我們數億光年，非常年老，因此樣子也不規則顏色也較紅，而圖中右下角的則是銀暈中的一個球狀星團。

Caption:: Glittering stars. Distorted galaxies. A cluster of more than 100,000 stars. The celestial objects in this six-panel photograph are just a sampling of the more than 300,000 stars and the thousands of distant galaxies seen in the image of a small region of the Andromeda galaxy's halo, a spherical cloud of stars around the galaxy. The image was taken with the Advanced Camera for Surveys aboard NASA's Hubble Space Telescope. This photograph shows some of the interesting details found in that image. The stars in these panels are located in Andromeda's halo. The galaxies seen in five of the panels represent some of the background galaxies located far beyond Andromeda. A few of them appear distorted, such as the curved red streak of material seen at top row, center. Their distorted shapes suggest that they collided with other galaxies. The white spherical object [bottom row, right] is a collection of more than 100,000 stars called a globular cluster, located in Andromeda's halo. Andromeda is located 2.5 million light-years from Earth.

Credit:: NASA, ESA and T.M. Brown (STScI)