NGC 147与NGC 185

NGC 147与NGC 185

ByNASA中文

2021年11月04日 NGC 147 and NGC 185 Image Credit & Copyright: Dan Bartlett Explanation: Dwarf galaxies NGC 147 (left) and NGC 185 stand side by side in this sharp telescopic portrait. The two are not-often-imaged satellites of M31, the great spiral Andromeda Galaxy, some 2.5 million light-years away. Their separation on the sky, less than one degree across a pretty field of view, translates to only about 35 thousand light-years at Andromeda’s distance, but Andromeda itself is found well outside this frame. Brighter and more famous satellite galaxies of Andromeda, M32 and M110, are seen closer to the great spiral. NGC 147 and NGC 185 have been identified as binary galaxies, forming a gravitationally stable binary system. But recently discovered faint dwarf galaxy Cassiopeia II also…

仙女星系方向的深空影像

仙女星系方向的深空影像

ByNASA中文

2021年9月8日 The Deep Sky Toward Andromeda Image Credit & License: Stefan Ziegenbalg Explanation: What surrounds the Andromeda galaxy? Out in space, Andromeda (M31) is closely surrounded by several small satellite galaxies, and further out it is part of the Local Group of Galaxies — of which our Milky Way galaxy is also a member. On the sky, however, gas clouds local to our Milky Way appear to surround M31 — not unlike how water clouds in Earth’s atmosphere may appear to encompass our Moon. The gas clouds toward Andromeda, however, are usually too faint to see. Enter the featured 45-degree long image — one of the deeper images yet taken of the broader Andromeda region. This image, sensitive to light specifically emitted by hydrogen gas,…

星系与宇宙沙粒

星系与宇宙沙粒

ByNASA中文

2021年8月14日 Island Universe, Cosmic Sand Image Credit & Copyright: Marzena Rogozinska Explanation: Stars in our own Milky Way Galaxy are scattered through this eye-catching field of view. From the early hours after midnight on August 13, the 30 second exposure of the night sky over Busko-Zdroj, Poland records the colorful and bright trail of a Perseid meteor. Seen near the peak of the annual Perseid meteor shower it flashes from lower left to upper right. The hurtling grain of cosmic sand, a piece of dust from periodic comet Swift-Tuttle, vaporized as it passed through planet Earth’s atmosphere at almost 60 kilometers per second. Just above and right of center, well beyond the stars of the Milky Way, lies the island universe known as M31 or…

紫外光波段的仙女座星系

紫外光波段的仙女座星系

ByNASA中文

2021年7月18日 The Andromeda Galaxy in Ultraviolet Image Credit: NASA, JPL-Caltech, GALEX Explanation: What does the Andromeda galaxy look like in ultraviolet light? Young blue stars circling the galactic center dominate. A mere 2.5 million light-years away, the Andromeda Galaxy, also known as M31, really is just next door as large galaxies go. Spanning about 230,000 light-years, it took 11 different image fields from NASA’s Galaxy Evolution Explorer (GALEX) satellite telescope to produce this gorgeous portrait of the spiral galaxy in ultraviolet light in 2003. While its spiral arms stand out in visible light images, Andromeda’s arms look more like rings in ultraviolet. The rings are sites of intense star formation and have been interpreted as evidence that Andromeda collided with its smaller neighboring elliptical galaxy…

单曝光影像里的仙女座星系

单曝光影像里的仙女座星系

ByNASA中文

2021年06月25日 Andromeda in a Single Shot Image Credit & Copyright: Miguel Claro (TWAN, Dark Sky Alqueva) Explanation: How far can you see? The Andromeda Galaxy, 2.5 million light years away, is the most distant object easily seen by the unaided eye. Other denizens of the night sky, like stars, clusters, and nebulae, are typically hundreds to thousands of light-years distant. That’s far beyond the Solar System but well within our own Milky Way Galaxy. Also known as M31, the external galaxy poses directly above a chimney in this well-planned deep night skyscape from an old mine in southern Portugal. The image was captured in a single exposure tracking the sky, so the foreground is slightly blurred by the camera’s motion while Andromeda itself looms large….

巴塔哥尼亚上空的仙女大星系

巴塔哥尼亚上空的仙女大星系

ByNASA中文

2020年11月25日 Andromeda over Patagonia Image Credit & Copyright: Gerardo Ferrarino Explanation: How far can you see? The Andromeda Galaxy at 2.5 million light years away is the most distant object easily seen with your unaided eye. Most other apparent denizens of the night sky — stars, clusters, and nebulae — typically range from a few hundred to a few thousand light-years away and lie well within our own Milky Way Galaxy. Given its distance, light from Andromeda is likely also the oldest light that you can see. Also known as M31, the Andromeda Galaxy dominates the center of the featured zoomed image, taken from the dunes of Bahía Creek, Patagonia, in southern Argentina. The image is a combination of 45 background images with one foreground…

萨丁尼亚岛的夜空

萨丁尼亚岛的夜空

ByNASA中文

2020年10月21日 A Night Sky Vista from Sardinia Image Credit & Copyright: Tomáš Slovinský Explanation: How many famous sky objects can you find in this image? The featured dark sky composite combines over 60 exposures spanning over 220 degrees to create a veritable menagerie of night sky wonders. Visible celestial icons include the Belt of Orion, the Orion Nebula, the Andromeda Galaxy, the California Nebula, and bright stars Sirius and Betelgeuse. You can verify that you found these, if you did, by checking an annotated version of the image. A bit harder, though, is finding Polaris and the Big Dipper. Also discernible are several meteors from the Quandrantids meteor shower, red and green airglow, and two friends of the astrophotographer. The picture was captured in January…

月亮与仙女座大星系

月亮与仙女座大星系

ByNASA中文

2020年9月25日 Moon over Andromeda Composite Image Credit & Copyright: Adam Block and Tim Puckett Explanation: The Great Spiral Galaxy in Andromeda (also known as M31), a mere 2.5 million light-years distant, is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small, faint, fuzzy patch, but because its surface brightness is so low, casual skygazers can’t appreciate the galaxy’s impressive extent in planet Earth’s sky. This entertaining composite image compares the angular size of the nearby galaxy to a brighter, more familiar celestial sight. In it, a deep exposure of Andromeda, tracing beautiful blue star clusters in spiral arms far beyond the bright yellow core, is combined with a typical view of a nearly full Moon….

仙女座大星系的气晕

仙女座大星系的气晕

ByNASA中文

2020年9月3日 A Halo for Andromeda Digital Illustration Credit: NASA, ESA, J. DePasquale and E. Wheatley (STScI) and Z. Levay Explanation: M31, the Andromeda Galaxy, is the closest large spiral galaxy to our Milky Way. Some 2.5 million light-years distant it shines in Earth’s night sky as a small, faint, elongated cloud just visible to the unaided eye. Invisible to the eye though, its enormous halo of hot ionized gas is represented in purplish hues for this digital illustration of our neighboring galaxy above rocky terrain. Mapped by Hubble Space Telescope observations of the absorption of ultraviolet light against distant quasars, the extent and make-up of Andromeda’s gaseous halo has been recently determined by the AMIGA project. A reservoir of material for future star formation, Andromeda’s…

M106方向的景观

M106方向的景观

ByNASA中文

2020 May 1 A View Toward M106 Image Credit & Copyright: Joonhwa Lee Explanation: Big, bright, beautiful spiral, Messier 106 dominates this cosmic vista. The nearly two degree wide telescopic field of view looks toward the well-trained constellation Canes Venatici, near the handle of the Big Dipper. Also known as NGC 4258, M106 is about 80,000 light-years across and 23.5 million light-years away, the largest member of the Canes II galaxy group. For a far far away galaxy, the distance to M106 is well-known in part because it can be directly measured by tracking this galaxy’s remarkable maser, or microwave laser emission. Very rare but naturally occurring, the maser emission is produced by water molecules in molecular clouds orbiting its active galactic nucleus. Another prominent…