棒旋星系NGC 6217

棒旋星系NGC 6217

2022年2月21日 Barred Spiral Galaxy NGC 6217 Image Credit: NASA, ESA, and the Hubble SM4 ERO Team Explanation: Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 6217, featured here, was captured in spectacular detail in this image taken by the Advanced Camera for Surveys on the orbiting Hubble Space Telescope in 2009. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bar of stars across the center, and a bright active nucleus that likely houses a supermassive black hole. Light takes about 60 million years to reach us from NGC 6217, which spans about 30,000…

IC 342:隐藏的星系

IC 342:隐藏的星系

2022年2月11日 IC 342: The Hidden Galaxy in Camelopardalis Image Credit & Copyright: Daniel Feller Explanation: Similar in size to large, bright spiral galaxies in our neighborhood, IC 342 is a mere 10 million light-years distant in the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is hidden from clear view and only glimpsed through the veil of stars, gas and dust clouds along the plane of our own Milky Way galaxy. Even though IC 342’s light is dimmed and reddened by intervening cosmic clouds, this sharp telescopic image traces the galaxy’s own obscuring dust, young star clusters, and glowing pink star forming regions along spiral arms that wind far from the…

M31:仙女座星系

M31:仙女座星系

2022年1月19日 M31: The Andromeda Galaxy Image Credit: Subaru (NAOJ), Hubble (NASA/ESA), Mayall (NSF); Processing & Copyright: R. Gendler & R. Croman Explanation: The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy. Even at some two and a half million light-years distant, this immense spiral galaxy — spanning over 200,000 light years — is visible, although as a faint, nebulous cloud in the constellation Andromeda. In contrast, a bright yellow nucleus, dark winding dust lanes, and expansive spiral arms dotted with blue star clusters and red nebulae, are recorded in this stunning telescopic image which combines data from orbiting Hubble with ground-based images from Subaru and Mayall. In only about 5 billion years, the Andromeda galaxy may be even…

NGC 1566:西班牙舞者螺旋星系

NGC 1566:西班牙舞者螺旋星系

2022年1月14日 NGC 1566: The Spanish Dancer Spiral Galaxy Image Credit & Copyright: Mark Hanson and Mike Selby Explanation: An island universe of billions of stars, NGC 1566 lies about 60 million light-years away in the southern constellation Dorado. Popularly known as the Spanish Dancer galaxy, it’s seen face-on from our Milky Way perspective. A gorgeous grand design spiral, this galaxy’s two graceful spiral arms span over 100,000 light-years, traced by bright blue star clusters, pinkish starforming regions, and swirling cosmic dust lanes. NGC 1566’s flaring center makes the spiral one of the closest and brightest Seyfert galaxies. It likely houses a central supermassive black hole wreaking havoc on surrounding stars, gas, and dust. In this sharp southern galaxy portrait, the spiky stars lie well within…

M101

M101

2021年11月27日 Messier 101 Image Credit: NASA, ESA, CFHT, NOAO; Acknowledgement – K.Kuntz (GSFC), F.Bresolin (U.Hawaii), J.Trauger (JPL), J.Mould (NOAO), Y.-H.Chu (U. Illinois) Explanation: Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier’s famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way. M101 was also one of the original spiral nebulae observed by Lord Rosse’s large 19th century telescope, the Leviathan of Parsontown. Assembled from 51 exposures recorded by the Hubble Space Telescope in the 20th and 21st centuries, with additional data from ground based telescopes, this mosaic spans about 40,000 light-years across the central region of M101 in one of the highest definition…

M33:三角大星系

M33:三角大星系

2021年11月12日 M33: The Triangulum Galaxy Image Credit & Copyright: Bernard Miller 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 planet Earth, this sharp image shows off M33’s blue star clusters and pinkish star forming regions along the galaxy’s loosely wound…

NGC 289:南天的涡漩

NGC 289:南天的涡漩

2021年10月15日 NGC 289: Swirl in the Southern Sky Image Credit & Copyright: Mike Selby Explanation: About 70 million light-years distant, gorgeous spiral galaxy NGC 289 is larger than our own Milky Way. Seen nearly face-on, its bright core and colorful central disk give way to remarkably faint, bluish spiral arms. The extensive arms sweep well over 100 thousand light-years from the galaxy’s center. At the lower right in this sharp, telescopic galaxy portrait the main spiral arm seems to encounter a small, fuzzy elliptical companion galaxy interacting with enormous NGC 289. Of course spiky stars are in the foreground of the scene. They lie within the Milky Way toward the southern constellation Sculptor. Tomorrow’s picture: Pixel in Space NGC 289:南天的涡漩 影像提供与版权: Mike Selby 说明: 在大约7千万光年远处的壮丽螺旋星系NGC…

鲁宾的星系

鲁宾的星系

2021年9月18日 Rubin’s Galaxy Image Credit: NASA, ESA, B. Holwerda (University of Louisville) Explanation: In this Hubble Space Telescope image the bright, spiky stars lie in the foreground toward the heroic northern constellation Perseus and well within our own Milky Way galaxy. In sharp focus beyond is UGC 2885, a giant spiral galaxy about 232 million light-years distant. Some 800,000 light-years across compared to the Milky Way’s diameter of 100,000 light-years or so, it has around 1 trillion stars. That’s about 10 times as many stars as the Milky Way. Part of an investigation to understand how galaxies can grow to such enormous sizes, UGC 2885 was also part of An Interesting Voyage and astronomer Vera Rubin’s pioneering study of the rotation of spiral galaxies. Her…

M51:涡状星系

M51:涡状星系

2021年9月2日 M51: The Whirlpool Galaxy Image Credit & Copyright: Josep Drudis 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 (top), NGC 5195. The pair are about 31 million light-years distant and officially lie within the angular boundaries of the small constellation Canes Venatici. Though M51 looks faint and fuzzy to…

M74:完美的螺旋星系

M74:完美的螺旋星系

2021年8月13日 A Perfect Spiral Image Credit: NASA, ESA, Hubble, HLA; Processing: Mehmet Hakan Ozsarac Explanation: If not perfect then this spiral galaxy is at least one of the most photogenic. An island universe of about 100 billion stars, 32 million light-years away toward the constellation Pisces, M74 presents a gorgeous face-on view. Classified as an Sc galaxy, the grand design of M74’s graceful spiral arms are traced by bright blue star clusters and dark cosmic dust lanes. This sharp composite was constructed from image data recorded by the Hubble Space Telescope’s Advanced Camera for Surveys. Spanning about 30,000 light-years across the face of M74, it includes exposures recording emission from hydrogen atoms, highlighting the reddish glow of the galaxy’s large star-forming regions. With a lower…