240809 - C4 "Iris" nebula
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click image to enlarge
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ASTRO:
type=reflection nebula mag=6.8 const=Cepheus dist=1300 ly size=7 ly IMAGE: location=Utah Desert Remote Observatories (SW Utah) BrtlCls=1 exposure=CMOS Mono; 39x300s (3.3h), G100 EQUIPMENT: camera=ZWO ASI6200MM-Pro optics=16" Dream Astrograph newtonian, FL=1500mm, f/3.75 filters=Chroma L, R, G & B mount=Software Bisque Paramount ME guiding=(none) SOFTWARE: acquisition=Voyager processing=PixInsight (RCAstro), Photoshop, LrC |
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Like delicate cosmic flower petals, these clouds of interstellar dust and gas have blossomed in the fertile star fields of the constellation Cepheus. The Iris Nebula (also known as Caldwell 4 and NGC 7023) is a bright reflection nebula. The designation NGC 7023 refers to the open star cluster within the larger reflection nebula designated LBN 487. The nebula shines at magnitude +6.8, and is illuminated by a magnitude +7.4 star designated SAO 19158. It lies appx 1,300 light-years away from Earth. As shown here, the Iris Nebula spans about 7 light-years across.
This is not the only nebula in the sky to evoke the imagery of flowers. Still, digital images often show off the nebula's range of colors and symmetries. Within the Iris, dusty nebular material surrounds a massive, hot, young star in its formative years. Central filaments of cosmic dust glow with photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible light. The dominant color of the nebula is blue, characteristic of dust grains reflecting starlight. Dark, obscuring clouds of dust and cold molecular gas are also present and can lead the eye to see other convoluted and fantastic shapes.
Infrared observations indicate that this nebula may contain complex carbon molecules known as Polycyclic Aromatic Hydrocarbons (or PAH's) which are common on Earth due to the burning of fossil fuels, and because they are present in many nebulae, are believed to be evidence of active star formation.
This object's outer lying dark and dusty clouds are extremely challenging to photograph due to their being so faint. That, together with the brightness of the core region at the center of the nebula, makes for an exceptionally high dynamic range. In response, we chose to use outside resources to capture the image data. In particular, the 16 inch "Dreamscope" of Utah Desert Remote Observatories (URDO) was used. Mr. Craig Stocks, the lead operator of that facility, provided us with a wonderful experience, and exceptional results. URDO is located in southwestern Utah at a dark (Bortle1) location. That location, with its dark skies, its high incidence of clear conditions, and reasonably high and dry altitude, makes for a perfect location to capture images like this one.
This is not the only nebula in the sky to evoke the imagery of flowers. Still, digital images often show off the nebula's range of colors and symmetries. Within the Iris, dusty nebular material surrounds a massive, hot, young star in its formative years. Central filaments of cosmic dust glow with photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible light. The dominant color of the nebula is blue, characteristic of dust grains reflecting starlight. Dark, obscuring clouds of dust and cold molecular gas are also present and can lead the eye to see other convoluted and fantastic shapes.
Infrared observations indicate that this nebula may contain complex carbon molecules known as Polycyclic Aromatic Hydrocarbons (or PAH's) which are common on Earth due to the burning of fossil fuels, and because they are present in many nebulae, are believed to be evidence of active star formation.
This object's outer lying dark and dusty clouds are extremely challenging to photograph due to their being so faint. That, together with the brightness of the core region at the center of the nebula, makes for an exceptionally high dynamic range. In response, we chose to use outside resources to capture the image data. In particular, the 16 inch "Dreamscope" of Utah Desert Remote Observatories (URDO) was used. Mr. Craig Stocks, the lead operator of that facility, provided us with a wonderful experience, and exceptional results. URDO is located in southwestern Utah at a dark (Bortle1) location. That location, with its dark skies, its high incidence of clear conditions, and reasonably high and dry altitude, makes for a perfect location to capture images like this one.