碰撞螺旋星系Arp 274

碰撞螺旋星系Arp 274

ByNASA中文

2023年1月23日 The Colliding Spiral Galaxies of Arp 274 Image Credit: NASA, ESA, Hubble; Processing & Copyright: Mehmet Hakan Özsaraç Explanation: Two galaxies are squaring off in Virgo and here are the latest pictures. When two galaxies collide, the stars that compose them usually do not. This is because galaxies are mostly empty space and, however bright, stars only take up only a small fraction of that space. But during the collision, one galaxy can rip the other apart gravitationally, and dust and gas common to both galaxies does collide. If the two galaxies merge, black holes that likely resided in each galaxy center may eventually merge. Because the distances are so large, the whole thing takes place in slow motion — over hundreds of millions…

CG4: 云球与星系

CG4: 云球与星系

ByNASA中文

2023年1月4日 CG4: The Globule and the Galaxy Image Credit & Copyright: Mike Selby & Mark Hanson Explanation: Can a gas cloud eat a galaxy? It’s not even close. The “claw” of this odd looking “creature” in the featured photo is a gas cloud known as a cometary globule. This globule, however, has ruptured. Cometary globules are typically characterized by dusty heads and elongated tails. These features cause cometary globules to have visual similarities to comets, but in reality they are very much different. Globules are frequently the birthplaces of stars, and many show very young stars in their heads. The reason for the rupture in the head of this object is not yet known. The galaxy to the left of the globule is huge, very…

M88

M88

ByNASA中文

2022年12月28日 Messier 88 Image Credit & Copyright: Adam Block, Mt. Lemmon SkyCenter, U. Arizona Explanation: Charles Messier described the 88th entry in his 18th century catalog of Nebulae and Star Clusters as a spiral nebula without stars. Of course the gorgeous M88 is now understood to be a galaxy full of stars, gas, and dust, not unlike our own Milky Way. In fact, M88 is one of the brightest galaxies in the Virgo Galaxy Cluster some 50 million light-years away. M88’s beautiful spiral arms are easy to trace in this sharp cosmic portait. The arms are lined with young blue star clusters, pink star-forming regions, and obscuring dust lanes extending from a yellowish core dominated by an older population of stars. Spiral galaxy M88 spans…

河外星系特写: NGC 6744

河外星系特写: NGC 6744

ByNASA中文

2022年11月25日 NGC 6744: Extragalactic Close-Up Image Credit: NASA, ESA, and the LEGUS team Explanation: Beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across. That’s larger than the Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo, with its galactic disk tilted towards our line of sight. This Hubble close-up of the nearby island universe spans about 24,000 light-years or so across NGC 6744’s central region. The Hubble view combines visible light and ultraviolet image data. The giant galaxy’s yellowish core is dominated by the visible light from old, cool stars. Beyond the core are star-forming regions and young star clusters scattered along the inner spiral arms. NGC 6744’s young star clusters are bright at ultraviolet wavelengths, shown in blue…

M33: 三角大星系

M33: 三角大星系

ByNASA中文

2022年11月3日 M33: The Triangulum Galaxy Image Credit & Copyright: Processing – Robert Gendler Data – Hubble Legacy Archive, KPNO, NOIRLab, NSF, Aura, Amateur Sources Explanation: The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy and astronomers in these two galaxies would likely have spectacular views of each other’s grand spiral star systems. As for the view from the Milky Way, this sharp image combines data…

棒旋星系NGC 1300

棒旋星系NGC 1300

ByNASA中文

2022年10月16日 Barred Spiral Galaxy NGC 1300 Image Credit: NASA ESA, Hubble Heritage Explanation: Across the center of this spiral galaxy is a bar. And at the center of this bar is smaller spiral. And at the center of that spiral is a supermassive black hole. This all happens in the big, beautiful, barred spiral galaxy cataloged as NGC 1300, a galaxy that lies some 70 million light-years away toward the constellation of the river Eridanus. This Hubble Space Telescope composite view of the gorgeous island universe is one of the most detailed Hubble images ever made of a complete galaxy. NGC 1300 spans over 100,000 light-years and the Hubble image reveals striking details of the galaxy’s dominant central bar and majestic spiral arms. How the…

NGC 4631：鲸鱼星系

NGC 4631：鲸鱼星系

ByNASA中文

2022年10月6日 NGC 4631: The Whale Galaxy Image Credit & Copyright: Michael Sherick Explanation: NGC 4631 is a big beautiful spiral galaxy. Seen edge-on, it lies only 25 million light-years away in the well-trained northern constellation Canes Venatici. The galaxy’s slightly distorted wedge shape suggests to some a cosmic herring and to others its popular moniker, The Whale Galaxy. Either way, it is similar in size to our own Milky Way. In this sharp color image, the galaxy’s yellowish core, dark dust clouds, bright blue star clusters, and red star forming regions are easy to spot. A companion galaxy, the small elliptical NGC 4627 is just above the Whale Galaxy. Faint star streams seen in deep images are the remnants of small companion galaxies disrupted by…

星系NGC 7331特写

星系NGC 7331特写

ByNASA中文

2022年9月22日 NGC 7331 Close Up Image Credit & License: ESA/Hubble & NASA/D. Milisavljevic (Purdue University) Explanation: Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier’s famous 18th century catalog. Since the galaxy’s disk is inclined to our line-of-sight, long telescopic exposures often result in an image that evokes a strong sense of depth. This Hubble Space Telescope close-up spans some 40,000 light-years. The galaxy’s magnificent spiral arms feature dark obscuring dust lanes, bright bluish clusters of massive young stars, and the telltale reddish glow…

M51：涡状星系

M51：涡状星系

ByNASA中文

2022年9月2日 M51: The Whirlpool Galaxy Image Credit & Copyright: Fabian Neyer Explanation: Find the Big Dipper and follow the handle away from the dipper’s bowl until you get to the last bright star. Then, just slide your telescope a little south and west and you’ll come upon this stunning pair of interacting galaxies, the 51st entry in Charles Messier’s famous catalog. Perhaps the original spiral nebula, the large galaxy with well defined spiral structure is also cataloged as NGC 5194. Its spiral arms and dust lanes clearly sweep in front of its companion galaxy (left), NGC 5195. The pair are about 31 million light-years distant and officially lie within the angular boundaries of the small constellation Canes Venatici. In direct telescopic views, M51 looks faint…

哈勃望远镜的星暴星系M94

哈勃望远镜的星暴星系M94

ByNASA中文

2022年7月31日 Starburst Galaxy M94 from Hubble Image Credit: ESA/Hubble & NASA Explanation: Why does this galaxy have a ring of bright blue stars? Beautiful island universe Messier 94 lies a mere 15 million light-years distant in the northern constellation of the Hunting Dogs (Canes Venatici). A popular target for Earth-based astronomers, the face-on spiral galaxy is about 30,000 light-years across, with spiral arms sweeping through the outskirts of its broad disk. But this Hubble Space Telescope field of view spans about 7,000 light-years across M94’s central region. The featured close-up highlights the galaxy’s compact, bright nucleus, prominent inner dust lanes, and the remarkable bluish ring of young massive stars. The ring stars are all likely less than 10 million years old, indicating that M94 is…