行星状星云Jones-Emberson 1

行星状星云Jones-Emberson 1

ByNASA中文

2023年2月24日 Jones-Emberson 1 Image Credit & Copyright: Serge Brunier, Jean-François Bax, David Vernet, C2PU/OCA Explanation: Planetary nebula Jones-Emberson 1 is the death shroud of a dying Sun-like star. It lies some 1,600 light-years from Earth toward the sharp-eyed constellation Lynx. About 4 light-years across, the expanding remnant of the dying star’s atmosphere was shrugged off into interstellar space, as the star’s central supply of hydrogen and then helium for fusion was finally depleted after billions of years. Visible near the center of the planetary nebula is what remains of the stellar core, a blue-hot white dwarf star. Also known as PK 164 +31.1, the nebula is faint and very difficult to glimpse at a telescope’s eyepiece. But this deep broadband image combining 22 hours of…

NGC 6164: 龙蛋星云及其外晕

NGC 6164: 龙蛋星云及其外晕

ByNASA中文

2022年12月26日 NGC 6164: Dragon’s Egg Nebula and Halo Image Credit & Copyright: Russell Croman Explanation: The star at the center created everything. Known as the Dragon’s Egg, this star — a rare, hot, luminous O-type star some 40 times as massive as the Sun — created not only the complex nebula (NGC 6164) that immediately surrounds it, but also the encompassing blue halo. Its name is derived, in part, from the region’s proximity to the picturesque NGC 6188, known as the fighting Dragons of Ara. In another three to four million years the massive star will likely end its life in a supernova explosion. Spanning around 4 light-years, the nebula itself has a bipolar symmetry making it similar in appearance to more common planetary nebulae…

NGC 7293：螺旋星云

NGC 7293：螺旋星云

ByNASA中文

2022年12月7日 NGC 7293: The Helix Nebula Image Credit & Copyright: Tommaso Stella Explanation: A mere seven hundred light years from Earth, toward the constellation Aquarius, a sun-like star is dying. The dying star’s last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this final phase of stellar evolution. Combining narrow band image data from emission lines of hydrogen atoms in red and oxygen atoms in blue-green hues, it shows tantalizing details of the Helix, including its bright inner region about 3 light-years across. The white dot at the Helix’s center is this Planetary Nebula’s hot, central star. A simple looking nebula at first glance, the Helix is now understood to have…

韦伯的南环状星云

韦伯的南环状星云

ByNASA中文

2022年7月14日 Webb’s Southern Ring Nebula Image Credit: NASA, ESA, CSA, STScI, NIRCam Explanation: Cataloged as NGC 3132 the Southern Ring Nebula is a planetary nebula, the death shroud of a dying sun-like star some 2,500 light-years from Earth. Composed of gas and dust the stunning cosmic landscape is nearly half a light-year in diameter, explored in unprecedented detail by the James Webb Space Telescope. In this NIRCam image the bright star near center is a companion of the dying star. In mutual orbit, the star whose transformation has ejected the nebula’s gas and dust shells over thousands of years is the fainter stellar partner. Evolving to become a white dwarf, the faint star appears along the diffraction spike extending toward the 8 o’clock position. This…

行星状星云Abell 7

行星状星云Abell 7

ByNASA中文

2022年5月21日 Planetary Nebula Abell 7 Image Credit & Copyright: Donald Waid, Ron Dilulio Explanation: Very faint planetary nebula Abell 7 is some 1,800 light-years distant, just south of Orion in planet Earth’s skies in the constellation Lepus, The Hare. Surrounded by Milky Way stars and near the line-of-sight to distant background galaxies, its generally simple spherical shape, about 8 light-years in diameter, is outlined in this deep telescopic image. Within its confines are beautiful, more complex details enhanced by the use of narrowband filters. Emission from hydrogen is shown in reddish hues with oxygen emission mapped to green and blue colors, giving Abell 7 a natural appearance that would otherwise be much too faint to be appreciated by eye. A planetary nebula represents a very…

蛇妖星云

蛇妖星云

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2022年3月25日 The Medusa Nebula Image Credit & Copyright: Damien Cannane Explanation: Braided and serpentine filaments of glowing gas suggest this nebula’s popular name, The Medusa Nebula. Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away in the constellation Gemini. Like its mythological namesake, the nebula is associated with a dramatic transformation. The planetary nebula phase represents a final stage in the evolution of low mass stars like the sun as they transform themselves from red giants to hot white dwarf stars and in the process shrug off their outer layers. Ultraviolet radiation from the hot star powers the nebular glow. The Medusa’s transforming star is the faint one near the center of the overall bright crescent shape. In…

见光及X射线波段的猫眼星云

见光及X射线波段的猫眼星云

ByNASA中文

2021年11月07日 The Cat’s Eye Nebula in Optical and X-ray Image Credit: NASA, ESA, Hubble Legacy Archive; Chandra X-ray Obs.; Processing & Copyright: Rudy Pohl Explanation: To some it looks like a cat’s eye. To others, perhaps like a giant cosmic conch shell. It is actually one of brightest and most highly detailed planetary nebula known, composed of gas expelled in the brief yet glorious phase near the end of life of a Sun-like star. This nebula’s dying central star may have produced the outer circular concentric shells by shrugging off outer layers in a series of regular convulsions. The formation of the beautiful, complex-yet-symmetric inner structures, however, is not well understood. The featured image is a composite of a digitally sharpened Hubble Space Telescope image…

NGC 7293: 螺旋星云

NGC 7293: 螺旋星云

ByNASA中文

2021年10月14日 NGC 7293: The Helix Nebula Image Credit & Copyright: Ignacio Diaz Bobillo Explanation: A mere seven hundred light years from Earth, toward the constellation Aquarius, a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this final phase of stellar evolution. A total of 90 hours of exposure time have gone in to creating this expansive view of the nebula. Combining narrow band image data from emission lines of hydrogen atoms in red and oxygen atoms in blue-green hues, it shows remarkable details of the Helix’s brighter inner region about 3 light-years across. The white dot at the Helix’s center is this Planetary Nebula’s hot,…

M27：哑铃星云

M27：哑铃星云

ByNASA中文

2021年7月12日 M27: The Dumbbell Nebula Image Credit & Copyright: Bray Falls & Keith Quattrocchi Explanation: What will become of our Sun? The first hint of our Sun’s future was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets. The 27th object on Messier’s list, now known as M27 or the Dumbbell Nebula, is a planetary nebula, one of the brightest planetary nebulae on the sky — and visible toward the constellation of the Fox (Vulpecula) with binoculars. It takes light about 1000 years to reach us from M27, featured here in colors emitted by hydrogen and oxygen. We now know that in about 6 billion years, our Sun will shed its outer…

行星状星云Mz3: 蚂蚁星云

行星状星云Mz3: 蚂蚁星云

ByNASA中文

2021年04月25日 Planetary Nebula Mz3: The Ant Nebula Image Credit: R. Sahai (JPL) et al., Hubble Heritage Team, ESA, NASA Explanation: Why isn’t this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round? Clues might include the high 1000-kilometer per second speed of the expelled gas, the light-year long length of the structure, and the magnetism of the star featured here at the nebula’s center. One possible answer is that Mz3 is hiding a second, dimmer star that orbits close in to the bright star. A competing hypothesis holds that the central star’s own spin…