NGC 7023：鸢尾花星云

NGC 7023：鸢尾花星云

ByNASA中文

2023年9月2日 NGC 7023: The Iris Nebula Image Credit & Copyright: Lorand Fenyes Explanation: These cosmic clouds have blossomed 1,300 light-years away in the fertile starfields of the constellation Cepheus. Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers. Still, this deep telescopic image shows off the Iris Nebula’s range of colors and symmetries embedded in surrounding fields of interstellar dust. Within the Iris itself, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the reflection nebula glow with a faint reddish photoluminescence as some dust grains effectively convert the star’s invisible ultraviolet radiation to visible red light. Infrared observations…

南冕座的恒星和尘埃

南冕座的恒星和尘埃

ByNASA中文

2023年6月22日 Stars and Dust across Corona Australis Image Credit & Copyright: Alessandro Cipolat Bares Explanation: Cosmic dust clouds cross a rich field of stars in this telescopic vista near the northern boundary of Corona Australis, the Southern Crown. Part of a sprawling molecular cloud complex this star forming region is a mere 500 light-years away. That’s about one third the distance of the more famous stellar nursery known as the Orion Nebula. The 2 degree wide frame would span 15 light-years at the clouds’ estimated distance. Mixed with bright nebulosities the dust clouds effectively block light from more distant background stars in the Milky Way and obscure from view embedded stars still in the process of formation. Large dark nebula Bernes 157 is on the…

NGC 1333：英仙座的恒星育婴室

NGC 1333：英仙座的恒星育婴室

ByNASA中文

2023年4月22日 NGC 1333: Stellar Nursery in Perseus Image Credit: Science – NASA, ESA, STScI, Processing – Varun Bajaj (STScI), Joseph DePasquale (STScI), Jennifer Mack (STScI) Explanation: In visible light NGC 1333 is seen as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, star-forming molecular cloud. This Hubble Space Telescope close-up frames a region just over 1 light-year wide at the estimated distance of NGC 1333. It shows details of the dusty region along with telltale hints of contrasty red emission from Herbig-Haro objects, jets and shocked glowing gas emanating from recently formed stars. In fact, NGC 1333 contains hundreds of stars…

编录号在1970附近的反射星云

编录号在1970附近的反射星云

ByNASA中文

2023年2月2日 Reflections on the 1970s Image Credit & Copyright: Daniel Stern Explanation: The 1970s are sometimes ignored by astronomers, like this beautiful grouping of reflection nebulae in Orion – NGC 1977, NGC 1975, and NGC 1973 – usually overlooked in favor of the substantial glow from the nearby stellar nursery better known as the Orion Nebula. Found along Orion’s sword just north of the bright Orion Nebula complex, these reflection nebulae are also associated with Orion’s giant molecular cloud about 1,500 light-years away, but are dominated by the characteristic blue color of interstellar dust reflecting light from hot young stars. In this sharp color image a portion of the Orion Nebula appears along the bottom border with the cluster of reflection nebulae at picture center….

M45: 阿特拉斯和普勒俄涅的女儿们

M45: 阿特拉斯和普勒俄涅的女儿们

ByNASA中文

2023年1月5日 Messier 45: The Daughters of Atlas and Pleione Image Credit & Copyright: Stefan Thrun Explanation: Hurtling through a cosmic dust cloud a mere 400 light-years away, the lovely Pleiades or Seven Sisters open star cluster is well-known for its striking blue reflection nebulae. It lies in the night sky toward the constellation Taurus and the Orion Arm of our Milky Way galaxy. The sister stars are not related to the dusty cloud though. They just happen to be passing through the same region of space. Known since antiquity as a compact grouping of stars, Galileo first sketched the star cluster viewed through his telescope with stars too faint to be seen by eye. Charles Messier recorded the position of the cluster as the 45th…

美丽的三叶星云

美丽的三叶星云

ByNASA中文

2022年8月5日 A Beautiful Trifid Image Credit & Copyright: Vikas Chander Explanation: The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid does illustrate three different types of astronomical nebulae; red emission nebulae dominated by light from hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. But the red emission region, roughly separated into three parts by obscuring dust lanes, is what lends the Trifid its popular name. Pillars and jets sculpted by newborn stars, above and right of the emission nebula’s center, appear in famous Hubble…

麒麟座V838的回光

麒麟座V838的回光

ByNASA中文

2022年6月26日 Light Echoes from V838 Mon Image Credit: NASA, ESA, H. E. Bond (STScI) Explanation: What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon’s outer surface suddenly greatly expanded with the result that it became one of the brighter stars in the Milky Way Galaxy in early 2002. Then, just as suddenly, it shrunk and faded. A stellar flash like this had never been seen before — supernovas and novas expel matter out into space. Although the V838 Mon flash appears to expel material into space, what is seen in the featured image from the Hubble Space Telescope is actually an outwardly expanding light echo of the original flash. In a light echo, light from the flash is reflected by successively…

参宿七与女巫头星云

参宿七与女巫头星云

ByNASA中文

2022年1月24日 Rigel and the Witch Head Nebula Image Credit & Copyright: José Mtanous Explanation: By starlight this eerie visage shines in the dark, a crooked profile evoking its popular name, the Witch Head Nebula. In fact, this entrancing telescopic portrait gives the impression that the witch has fixed her gaze on Orion’s bright supergiant star Rigel. More formally known as IC 2118, the Witch Head Nebula spans about 50 light-years and is composed of interstellar dust grains reflecting Rigel’s starlight. The blue color of the Witch Head Nebula and of the dust surrounding Rigel is caused not only by Rigel’s intense blue starlight but because the dust grains scatter blue light more efficiently than red. The same physical process causes Earth’s daytime sky to appear…

NGC 1333：英仙座的恒星育婴室

NGC 1333：英仙座的恒星育婴室

ByNASA中文

2021年11月11日 NGC 1333: Stellar Nursery in Perseus Image Credit & Copyright: Michael Sherick Explanation: NGC 1333 is seen in visible light as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, star-forming molecular cloud. This telescopic close-up spans about two full moons on the sky or just over 15 light-years at the estimated distance of NGC 1333. It shows details of the dusty region along with telltale hints of contrasty red emission from Herbig-Haro objects, jets and shocked glowing gas emanating from recently formed stars. In fact, NGC 1333 contains hundreds of stars less than a million years old, most still hidden…

NGC 7023：鸢尾花星云

NGC 7023：鸢尾花星云

ByNASA中文

2021年9月3日 NGC 7023: The Iris Nebula Image Credit & Copyright: Satwant Kumar Explanation: These cosmic clouds have blossomed 1,300 light-years away, in the fertile starfields of the constellation Cepheus. Called the Iris Nebula, NGC 7023 is not the only nebula to evoke the imagery of flowers. Still, this deep telescopic image shows off the Iris Nebula’s range of colors and symmetries, embedded in surrounding fields of interstellar dust. Within the Iris itself, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the reflection nebula glow with a faint reddish photoluminesence as some dust grains effectively convert the star’s invisible ultraviolet radiation to visible red light. Infrared observations…