NGC 1499: 加州星云

NGC 1499: 加州星云

ByNASA中文

2023年12月19日 NGC 1499: The California Nebula Image Credit & Copyright: Steven Powell Explanation: Could Queen Calafia‘s mythical island exist in space? Perhaps not, but by chance the outline of this molecular space cloud echoes the outline of the state of California, USA. Our Sun has its home within the Milky Way’s Orion Arm, only about 1,000 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. On the featured image, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot,…

仙后座“策”与幽灵状星云

仙后座“策”与幽灵状星云

ByNASA中文

2023年10月28日 The Ghosts of Gamma Cas Image Credit & Copyright: Guillaume Gruntz, Jean-François Bax Explanation: Gamma Cassiopeiae shines high in northern autumn evening skies. It’s the brightest spiky star in this telescopic field of view toward the constellation Cassiopeia. Gamma Cas shares the ethereal-looking scene with ghostly interstellar clouds of gas and dust, IC 59 (top left) and IC 63. About 600 light-years distant, the clouds aren’t actually ghosts. They are slowly disappearing though, eroding under the influence of energetic radiation from hot and luminous gamma Cas. Gamma Cas is physically located only 3 to 4 light-years from the nebulae. Slightly closer to gamma Cas, IC 63 is dominated by red H-alpha light emitted as hydrogen atoms ionized by the star’s ultraviolet radiation recombine with…

开心果星云

开心果星云

ByNASA中文

2023年8月22日 The Pistachio Nebula Credit & Copyright: Bray Falls & Chester Hall-Fernandez Explanation: This nebula had never been noted before. Newly discovered nebulas are usually angularly small and found by professionals using large telescopes. In contrast, the Pistachio Nebula was discovered by dedicated amateurs and, although faint, is nearly the size of the full Moon. In modern times, amateurs with even small telescopes can create long exposures over sky areas much larger than most professional telescopes can see. They can therefore discover both previously unknown areas of extended emission around known objects, as well as entirely unknown objects, like nebulas. The pictured Pistachio Nebula is shown in oxygen emission (blue) and hydrogen emission (red). The nature of the hot central star is currently unknown, and…

IC 4628：斑节虾星云

IC 4628：斑节虾星云

ByNASA中文

2023年7月26日 IC 4628: The Prawn Nebula Image Credit & Copyright: Daniel Stern Explanation: South of Antares, in the tail of the nebula-rich constellation Scorpius, lies emission nebula IC 4628. Nearby hot, massive stars, millions of years young, irradiate the nebula with invisible ultraviolet light, stripping electrons from atoms. The electrons eventually recombine with the atoms to produce the visible nebular glow, dominated by the red emission of hydrogen. At an estimated distance of 6,000 light-years, the region shown is about 250 light-years across, spanning over three full moons on the sky. The nebula is also cataloged as Gum 56 for Australian astronomer Colin Stanley Gum, but seafood-loving deep sky-enthusiasts might know this cosmic cloud as the Prawn Nebula. The graceful color image is a new…

M16：鹰状星云的深场影像

M16：鹰状星云的深场影像

ByNASA中文

2023年5月15日 M16: Eagle Nebula Deep Field Image Credit & Copyright: Gianni Lacroce Explanation: From afar, the whole thing looks like an eagle. A closer look at the Eagle Nebula, however, shows the bright region is actually a window into the center of a larger dark shell of dust. Through this window, a brightly-lit workshop appears where a whole open cluster of stars is being formed. In this cavity, tall pillars and round globules of dark dust and cold molecular gas remain where stars are still forming. Already visible are several young bright blue stars whose light and winds are burning away and pushing back the remaining filaments and walls of gas and dust. The Eagle emission nebula, tagged M16, lies about 6500 light years away,…

W5: 灵魂星云

W5: 灵魂星云

ByNASA中文

2023年3月14日 W5: The Soul Nebula Image Credit & Copyright: José Jiménez (Astromet) Explanation: Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the Soul Nebula can be found in the direction of the constellation Cassiopeia, whom Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river. Also known as Westerhout 5 (W5), the Soul Nebula houses several open clusters of stars, ridges and pillars darkened by cosmic dust, and huge evacuated bubbles formed by the winds of young massive stars. Located about 6,500 light years away, the Soul Nebula spans about 100 light years and is usually imaged next to its celestial neighbor the Heart…

Ou4：巨乌贼星云

Ou4：巨乌贼星云

ByNASA中文

2022年10月12日 Ou4: The Giant Squid Nebula Image Credit & Copyright: Tommy Lease Explanation: A mysterious squid-like cosmic cloud, this nebula is very faint, but also very large in planet Earth’s sky. In the image, composed with 30 hours of narrowband image data, it spans nearly three full moons toward the royal constellation Cepheus. Discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula’s bipolar shape is distinguished here by the telltale blue-green emission from doubly ionized oxygen atoms. Though apparently surrounded by the reddish hydrogen emission region Sh2-129, the true distance and nature of the Squid Nebula have been difficult to determine. Still, a more recent investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, the cosmic…

蝎虎座星云的波纹

蝎虎座星云的波纹

ByNASA中文

2022年9月14日 Waves of the Great Lacerta Nebula Image Credit & Copyright: Jarmo Ruuth, Telescope Live; Text: Ata Sarajedini (Florida Atlantic U., Astronomy Minute podcast) Explanation: It is one of the largest nebulas on the sky — why isn’t it better known? Roughly the same angular size as the Andromeda Galaxy, the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta). The emission nebula is difficult to see with wide-field binoculars because it is so faint, but also usually difficult to see with a large telescope because it is so great in angle — spanning about three degrees. The depth, breadth, waves, and beauty of the nebula — cataloged as Sharpless 126 (Sh2-126) — can best be seen and appreciated with a…

郁金香星云与天鹅座X-1

郁金香星云与天鹅座X-1

ByNASA中文

2022年9月1日 The Tulip and Cygnus X-1 Image Credit & Copyright: Peter Kohlmann Explanation: Framing a bright emission region, this telescopic view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula, the reddish glowing cloud of interstellar gas and dust is also found in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101. Nearly 70 light-years across, the complex and beautiful Tulip Nebula blossoms about 8,000 light-years away. Ultraviolet radiation from young energetic stars at the edge of the Cygnus OB3 association, including O star HDE 227018, ionizes the atoms and powers the emission from the Tulip Nebula. Also in the field of view is microquasar Cygnus X-1, one of the strongest…

移除恒星后的礁湖星云

移除恒星后的礁湖星云

ByNASA中文

2022年8月8日 The Lagoon Nebula without Stars Image Credit & Copyright: Sameer Dhar Explanation: Ridges of glowing interstellar gas and dark dust clouds inhabit the turbulent, cosmic depths of the Lagoon Nebula. Also known as M8, the bright star forming region is about 5,000 light-years distant. But it still makes for a popular stop on telescopic tours of the constellation Sagittarius, toward the center of our Milky Way Galaxy. Dominated by the telltale red emission of ionized hydrogen atoms recombining with stripped electrons, this stunning, deep view of the Lagoon is nearly 100 light-years across. Right of center, the bright, compact, hourglass shape is gas ionized and sculpted by energetic radiation and extreme stellar winds from a massive young star. In fact, although digitally removed from…