哈勃望远镜的木星和缩小的大红斑

哈勃望远镜的木星和缩小的大红斑

2022年1月9日 Hubble’s Jupiter and the Shrinking Great Red Spot Image Credit: NASA, ESA, Hubble, OPAL Program, STScI; Processing: Karol Masztalerz Explanation: What will become of Jupiter’s Great Red Spot? Gas giant Jupiter is the solar system’s largest world with about 320 times the mass of planet Earth. Jupiter is home to one of the largest and longest lasting storm systems known, the Great Red Spot (GRS), visible to the left. The GRS is so large it could swallow Earth, although it has been shrinking. Comparison with historical notes indicate that the storm spans only about one third of the exposed surface area it had 150 years ago. NASA’s Outer Planets Atmospheres Legacy (OPAL) program has been monitoring the storm more recently using the Hubble Space…

见光及X射线波段的猫眼星云

见光及X射线波段的猫眼星云

2021年11月07日 The Cat’s Eye Nebula in Optical and X-ray Image Credit: NASA, ESA, Hubble Legacy Archive; Chandra X-ray Obs.; Processing & Copyright: Rudy Pohl Explanation: To some it looks like a cat’s eye. To others, perhaps like a giant cosmic conch shell. It is actually one of brightest and most highly detailed planetary nebula known, composed of gas expelled in the brief yet glorious phase near the end of life of a Sun-like star. This nebula’s dying central star may have produced the outer circular concentric shells by shrugging off outer layers in a series of regular convulsions. The formation of the beautiful, complex-yet-symmetric inner structures, however, is not well understood. The featured image is a composite of a digitally sharpened Hubble Space Telescope image…

万圣节与鬼头星云

万圣节与鬼头星云

2021年10月24日 Halloween and the Ghost Head Nebula Image Credit: Mohammad Heydari-Malayeri (Observatoire de Paris) et al., ESA, NASA Explanation: Halloween’s origin is ancient and astronomical. Since the fifth century BC, Halloween has been celebrated as a cross-quarter day, a day halfway between an equinox (equal day / equal night) and a solstice (minimum day / maximum night in the northern hemisphere). With a modern calendar however, even though Halloween occurs next week, the real cross-quarter day will occur the week after. Another cross-quarter day is Groundhog Day. Halloween’s modern celebration retains historic roots in dressing to scare away the spirits of the dead. Perhaps a fitting tribute to this ancient holiday is this view of the Ghost Head Nebula taken with the Hubble Space Telescope….

NGC 520:哈勃拍摄的互撞星系

NGC 520:哈勃拍摄的互撞星系

2021年9月7日 NGC 520: Colliding Galaxies from Hubble Image Credit: NASA, ESA, Hubble; Processing & Copyright: William Ostling (The Astronomy Enthusiast) Explanation: Is this one galaxy or two? The jumble of stars, gas, and dust that is NGC 520 is now thought to incorporate the remains of two separate disk galaxies. A defining component of NGC 520 — as seen in great detail in the featured image from the Hubble Space Telescope — is its band of intricately interlaced dust running vertically down the spine of the colliding galaxies. A similar looking collision might be expected in a few billion years when our disk Milky Way Galaxy to collides with our large-disk galactic neighbor Andromeda (M31). The collision that defines NGC 520 started about 300 million…

M57: 环状星云的哈勃影像

M57: 环状星云的哈勃影像

2021年8月17日 M57: The Ring Nebula from Hubble Image Credit: NASA, ESA, Hubble Legacy Archive; Processing: Judy Schmidt Explanation: Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial circle. Its classic appearance is understood to be due to our own perspective, though. The recent mapping of the expanding nebula’s 3-D structure, based in part on this clear Hubble image,indicates that the nebula is a relatively dense, donut-like ring wrapped around the middle of a (American) football-shaped cloud of glowing gas. The view from planet Earth looks down the long axis of the football, face-on to the ring. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud…

环状星系AM 0644-741

环状星系AM 0644-741

2021年7月28日 Ring Galaxy AM 0644-741 Image Credit: NASA, ESA, Hubble, HLA; Processing: Jonathan Lodge Explanation: The rim of the large blue galaxy at the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. AM 0644-741 is known as a ring galaxy and was caused by an immense galaxy collision. When galaxies collide, they pass through each other and their individual stars rarely come into contact. The large galaxy’s ring-like shape is the result of the gravitational disruption caused by a small intruder galaxy passing through it. When this happens, interstellar gas and dust become compressed, causing a wave of star formation to move out from the impact point like a ripple across the surface of…

哈勃影像:猎户座星云

哈勃影像:猎户座星云

2021年06月29日 Orion Nebula: The Hubble View Image Credit: NASA, ESA, Hubble Legacy Archive; Processing: Francisco Javier Pobes Serrano Explanation: Few cosmic vistas excite the imagination like the Orion Nebula. Also known as M42, the nebula’s glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1,500 light-years away. The Orion Nebula offers one of the best opportunities to study how stars are born partly because it is the nearest large star-forming region, but also because the nebula’s energetic stars have blown away obscuring gas and dust clouds that would otherwise block our view – providing an intimate look at a range of ongoing stages of starbirth and evolution. The featured image of the Orion Nebula is among the sharpest…

NGC 602及后方的天体

NGC 602及后方的天体

2021年05月16日 NGC 602 and Beyond Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) – ESA/Hubble Collaboration Explanation: The clouds may look like an oyster, and the stars like pearls, but look beyond. Near the outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies 5 million year young star cluster NGC 602. Surrounded by natal gas and dust, NGC 602 is featured in this stunning Hubble image of the region. Fantastic ridges and swept back shapes strongly suggest that energetic radiation and shock waves from NGC 602’s massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the cluster’s center. At the estimated distance of the Small Magellanic Cloud, the…

螺旋星系M66的哈勃影像

螺旋星系M66的哈勃影像

2021年02月24日 Spiral Galaxy M66 from Hubble Image Credit: NASA, ESA, Hubble, Janice Lee; Processing & Copyright: Leo Shatz; Text: Karen Masters Explanation: It’s always nice to get a new view of an old friend. This stunning Hubble Space Telescope image of nearby spiral galaxy M66 is just that. A spiral galaxy with a small central bar, M66 is a member of the Leo Galaxy Triplet, a group of three galaxies about 30 million light years from us. The Leo Triplet is a popular target for relatively small telescopes, in part because M66 and its galactic companions M65 and NGC 3628 all appear separated by about the angular width of a full moon. The featured image of M66 was taken by Hubble to help investigate the…

NGC 1316的中心: 星系碰撞之后

NGC 1316的中心: 星系碰撞之后

2021年01月26日 Central NGC 1316: After Galaxies Collide Image Credit: NASA, ESA, Hubble; Processing & Copyright: Daniel Nobre Explanation: How did this strange-looking galaxy form? Astronomers turn detectives when trying to figure out the cause of unusual jumbles of stars, gas, and dust like NGC 1316. Inspection indicates that NGC 1316 is an enormous elliptical galaxy that somehow includes dark dust lanes usually found in a spiral galaxy. Detailed images taken by the Hubble Space Telescope shows details, however, that help in reconstructing the history of this gigantic tangle. Deep and wide images show huge collisional shells, while deep central images reveal fewer globular clusters of stars toward NGC 1316’s interior. Such effects are expected in galaxies that have undergone collisions or merging with other galaxies…