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Explanation: Is the heart and soul of our Galaxy located in Cassiopeia? Possibly not, but that is where two bright emission nebulas nicknamed Heart and Soul can be found. The Heart Nebula, officially dubbed IC 1805 and visible in the featured image on the upper right, has a shape reminiscent of a classical heart symbol. The shape is perhaps fitting for Valentine's Day. The Soul Nebula is officially designated IC 1871 and is visible on the lower left. Both nebulas shine brightly in the red light of energized hydrogen, one of three colors shown in this three-color montage. Light takes...

When a massive star collapsed in the Cassiopeia constellation, it generated a supernova explosion with some of the fastest shockwaves in the Milky Way. These speedy shock waves are one of the reasons the Cassiopeia A (Cas A) supernova remnant was chosen to be our Imaging X-ray Polarimetry Explorer’s (IXPE) first observed object. This composite image, made of data from IXPE, the Chandra Observatory, and the Hubble Telescope, shows Cas A. IXPE’s investigation of Cas A from Jan. 11 to Jan. 29, 2022, added crucial information about the behavior of exploded stars’ magnetic fields: scientists found that the magnetic fields...

According to reports in The Astronomer's Telegram, a star in the region of the constellation of Cassiopeia has just gone nova, and the glow is still visible in the night sky. If you live in the Northern Hemisphere and have even a basic telescope, you might want to head out and point it in that direction. The first detection was made on 18 March 2021 by amateur astronomer Yuji Nakamura from the Mie Prefecture in Japan. In four frames captured using a 135-millimeter lens and a 15-second exposure, a bright, magnitude 9.6 glow was visible where none had been just...

The nova (left) and the same patch of sky four days earlier. (Yuji Nakamura/NAOJ) According to reports in The Astronomer's Telegram, a star in the region of the constellation of Cassiopeia has just gone nova, and the glow is still visible in the night sky. If you live in the Northern Hemisphere and have even a basic telescope, you might want to head out and point it in that direction. The first detection was made on 18 March 2021 by amateur astronomer Yuji Nakamura from the Mie Prefecture in Japan. In four frames captured using a 135-millimeter lens and a...

An amateur astronomer just spotted a strange new object in the sky. And it’s bright enough for you to see with binoculars from your backyard. The discovery image (left) of a new nova that recently appeared in the constellation Cassiopeia. The right image shows how the same region of the sky appeared just four days prior. Yuji Nakamura At around 7 P.M. JST on the evening of March 18, Japanese amateur astronomer Yuji Nakamura spotted something strange: A new point of light in the familiar constellation Cassiopeia the Queen. Researchers at Kyoto University quickly followed up using the 3.8-meter Seimei...

Explanation: What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements, near its core, that could create stabilizing pressure with nuclear fusion. The resulting supernova remnant, nicknamed the Medulla Nebula for its brain-like shape, still glows in visible light by the heat generated by its collision with confining interstellar gas. Why the nebula also glows in X-ray light, though, remains a mystery. One hypothesis holds that an energetic pulsar was co-created that...

Explanation: A familiar, zigzag, W pattern in northern constellation Cassiopeia is traced by five bright stars in this colorful and broad mosaic. Stretching about 15 degrees across rich starfields, the celestial scene includes dark clouds, bright nebulae, and star clusters along the Milky Way. In yellow-orange hues Cassiopeia's alpha star Shedar is a standout though. The yellowish giant star is cooler than the Sun, over 40 times the solar diameter, and so luminous it shines brightly in Earth's night from 230 light-years away. A massive, rapidly rotating star at the center of the W, bright Gamma Cas is about 550...

Explanation: This cosmic close-up looks deep inside the Soul Nebula. The dark and brooding dust clouds outlined by bright ridges of glowing gas are cataloged as IC 1871. About 25 light-years across, the telescopic field of view spans only a small part of the much larger Heart and Soul nebulae. At an estimated distance of 6,500 light-years the star-forming complex lies within the Perseus spiral arm of the Milky Way, seen in planet Earth's skies toward the constellation Cassiopeia. An example of triggered star formation, the dense star-forming clouds of IC 1871 are themselves sculpted by the intense winds and...

Explanation: What's that inside the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. The nebula glows brightly in red light emitted by its most prominent element: hydrogen. The red glow and the larger shape are all created by a small group of stars near the nebula's center. In the center of the Heart Nebula are young stars from the open star cluster Melotte 15 that are eroding away several picturesque dust pillars with their energetic light and winds. The open cluster of stars contains a few bright stars nearly 50 times...

Explanation: How do stars form? Images of the star forming region W5 like those in the infrared by NASA's Wide Field Infrared Survey Explorer (WISE) satellite provide clear clues with indications that massive stars near the center of empty cavities are older than stars near the edges. A likely reason for this is that the older stars in the center are actually triggering the formation of the younger edge stars. The triggered star formation occurs when hot outflowing gas compresses cooler gas into knots dense enough to gravitationally contract into stars. In the featured scientifically-colored infrared image, spectacular pillars, left...

Explanation: Look through the cosmic cloud cataloged as NGC 281 and you might miss the stars of open cluster IC 1590. But, formed within the nebula, that cluster's young, massive stars ultimately power the pervasive nebular glow. The eye-catching shapes looming in this portrait of NGC 281 are sculpted columns and dense dust globules seen in silhouette, eroded by intense, energetic winds and radiation from the hot cluster stars. If they survive long enough, the dusty structures could also be sites of future star formation. Playfully called the Pacman Nebula because of its overall shape, NGC 281 is about 10,000...

Explanation: Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Below and left of the Bubble's center is a hot, O star, several hundred thousand times more luminous and around 45 times more massive than the Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The...

Explanation: Is the heart and soul of our Galaxy located in Cassiopeia? Possibly not, but that is where two bright emission nebulas nicknamed Heart and Soul can be found. The Heart Nebula, officially dubbed IC 1805 and visible in the above zoomable view on the right, has a shape reminiscent of a classical heart symbol. Both nebulas shine brightly in the red light of energized hydrogen. Several young open clusters of stars populate the image and are visible above in blue, including the nebula centers. Light takes about 6,000 years to reach us from these nebulas, which together span roughly...

Explanation: Now sweeping high above the ecliptic plane, Comet Lemmon has faded dramatically in planet Earth's night sky as it heads for the outer solar system. Some 16 light-minutes (2 AU) from the Sun, it still sports a greenish coma though, posing on the right in this 4 degree wide telescopic view from last Saturday with deep sky star clusters and nebulae in Cassiopeia. In fact, the rich background skyscape is typical within the boundaries of the boastful northern constellation that lie along the crowded starfields of the Milky Way. Included near center is open star cluster M52 about 5,000...

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, who Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river. The Soul Nebula houses several open clusters of stars, a large radio source known as W5, 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...

Explanation: The aftermath of a cosmic cataclysm, supernova remnant Cassiopeia A (Cas A) is a comfortable 11,000 light-years away. Light from the Cas A supernova, the death explosion of a massive star, first reached Earth just 330 years ago. Still expanding, the explosion's debris cloud spans about 15 light-years near the center of this composite image. The scene combines color data of the starry field and fainter filaments of material at optical energies with image data from the orbiting NuSTAR X-ray telescope. Mapped to false colors, the X-ray data in blue hues trace the fragmented outer ring of the expanding...

Explanation: Every book has a first page and every catalog a first entry. And so this lovely blue cosmic cloud begins the van den Bergh Catalog (vdB) of stars surrounded by reflection nebulae. Interstellar dust clouds reflecting the light of the nearby stars, the nebulae usually appear blue because scattering by the dust grains is more effective at shorter (bluer) wavelengths. The same type of scattering gives planet Earth its blue daytime skies. Van den Bergh's 1966 list contains a total of 158 entries more easily visible from the northern hemisphere, including bright Pleiades cluster stars and other popular targets...

Explanation: Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Above and right of the Bubble's center is a hot, O star, several hundred thousand times more luminous and around 45 times more massive than the Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The...

Explanation: Lurking behind dust and stars near the plane of our Milky Way Galaxy, IC 10 is a mere 2.3 million light-years distant. Even though its light is dimmed by intervening dust, the irregular dwarf galaxy still shows off vigorous star-forming regions that shine with a telltale reddish glow in this colorful skyscape. In fact, also a member of the Local Group of galaxies, IC 10 is the closest known starburst galaxy. Compared to other Local Group galaxies, IC 10 has a large population of newly formed stars that are massive and intrinsically very bright, including a luminous X-ray binary...

Explanation: These bright rims and flowing shapes suggest to some melting ice cream on a cosmic scale. Looking toward the constellation Cassiopeia, the colorful (zoomable) skyscape features the swept back, comet-shaped clouds IC 59 (left) and IC 63. About 600 light-years distant, the clouds aren't actually melting, but they are slowly dissipating under the influence of ionizing ultraviolet radiation from hot,luminous star gamma Cass. Gamma Cass is physically located only 3 to 4 light-years from the nebulae, just off the upper right edge of the frame. In fact, slightly closer to gamma Cass, IC 63 is dominated by red H-alpha...