250624 Sh2-136 "Ghosts Temple" nebula
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click image to enlarge
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ASTRO:
type=Emission nebula mag=8.0 const=Cygnus dist=1800 ly size=31 ly IMAGE: location=Utah Desert Remote Observatories (SW Utah) BrtlCls=1 exposure=CMOS Mono; 40x300s (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 (URDO)=Voyager processing (CNPAstro)=PixInsight (RCAstro), Photoshop (Web Sharp Pro), LrC |
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The Ghosts Temple, designated Sh2-136, and VdB141 is a reflection nebula located in the constellation Cepheus. It lies near the open star cluster NGC 7023. Looking at this image, the nebula's common name is easily understood. Scientifically, the formation is referred to as a Bok Globule, which measures over 2 light-years across. There are several stars embedded, whose reflected light make the nebula appear lit from within and emitting a yellowish-brown color.
In astronomy, Bok globules are isolated and relatively small dark nebulae, containing dense cosmic dust and gas from which star formation may take place. They are found within H II regions, and typically have a mass of anywhere from 2 to 50 solar masses contained within a region typically 1 to 2 light years across . They usually contain molecular hydrogen (H2), carbon oxides, helium, and silicate dust.
Bok globules were first observed by Dutch-American astronomer Bartholomeus ("Bart") Bok in the 1940s. At the time, Dr. Bok was an Associate Professor of Astronomy at Harvard University, where later he would be awarded the Robert Wheeler Wilson Chair in Astronomy along with full Professorship. Still later he became Associate Director of Harvard Observatory. In an article published in 1947, Dr. Bok hypothesized that these clouds were "similar to insect's cocoons" that were undergoing gravitational collapse to form new stars, and from which stars and star clusters would eventually be born. This hypothesis was difficult to verify due to the observational difficulties of establishing what was happening inside a dense dark cloud that obscured visible light within it from being emitted out into outer space. It wasn't until 1990, well after Dr. Bok's passing that an analysis using near-infrared observations was published confirming that stars were indeed being born inside Bok globules.
Known to be some of the coldest objects in the natural universe, observations have revealed that some Bok globules contain embedded warm sources, others contain Herbig–Haro objects, and still others show outflows of molecular gas, a known by-product of the stellar birthing process. Modern techniques including millimeter-wave emission line analysis have provided evidence for the in-fall of material onto accreting protostars. It is now thought that a typical Bok globule may contain up to as much as 10 solar masses of material within its boundaries, and that they most commonly result in the formation of double, or multi-star systems, including open star clusters.
Bok globules are a subject of intense research by professional astronomers; but, the exact nature of their structure and density still remain somewhat of a mystery. Investigative methods applied so far have relied on the study of column density derived from near-infrared extinction. Even the labor-intensive effort of star counting is sometimes used as attempts continue to probe these objects further. As noted elsewhere in this collection, one aspect of the amateur astronomy hobby that it makes so fascinating is knowing that scientific research continues on many objects like Bok Globules that fill our telescopes with strange, fascinating and beautiful objects; even as scientists continue their efforts to improve our understanding beyond the current state of the science.
This object's outer lying dark and dusty clouds are extremely challenging to photograph due to their being so faint. A "fast" telescope (one having a focal ratio of f/4.0 or better) is really needed to capture those faint details and provide the contrast needed to produce a quality image. In response, we chose to call upon outside resources to assist with capturing the sub-frame data. Giving credit where it is due, the "Dreamscope" of Utah Desert Remote Observatories (UDRO) was used. Mr. Craig Stocks, the lead operator of that facility, provided us with a wonderful experience, and exceptional results. His telescope is a 16" FL=1500mm f/3.75 research-quality Newtonian telescope manufactured by Dream Aerospace Systems, Ltd. It has an ASI6200MM-Pro full-frame mono camera mounted on it with Chroma L, R, G, & B broad-band filters; and, it is mounted on a Paramount ME mount with no guiding assist at all. It's an amazing rig! UDRO is located in southwestern Utah at a dark, (Bortle1) location. That location, with its dark skies, its high incidence of clear conditions, reasonably high and dry altitude, and when put together with the fast optics of the Dreamscope, provides perfect conditions to capture images like this one. Once the raw data was acquired, processing was completed using CNP Astronomy's in-house resources. Thank-You's and "Kudos" to Craig and his Team for their help!
In astronomy, Bok globules are isolated and relatively small dark nebulae, containing dense cosmic dust and gas from which star formation may take place. They are found within H II regions, and typically have a mass of anywhere from 2 to 50 solar masses contained within a region typically 1 to 2 light years across . They usually contain molecular hydrogen (H2), carbon oxides, helium, and silicate dust.
Bok globules were first observed by Dutch-American astronomer Bartholomeus ("Bart") Bok in the 1940s. At the time, Dr. Bok was an Associate Professor of Astronomy at Harvard University, where later he would be awarded the Robert Wheeler Wilson Chair in Astronomy along with full Professorship. Still later he became Associate Director of Harvard Observatory. In an article published in 1947, Dr. Bok hypothesized that these clouds were "similar to insect's cocoons" that were undergoing gravitational collapse to form new stars, and from which stars and star clusters would eventually be born. This hypothesis was difficult to verify due to the observational difficulties of establishing what was happening inside a dense dark cloud that obscured visible light within it from being emitted out into outer space. It wasn't until 1990, well after Dr. Bok's passing that an analysis using near-infrared observations was published confirming that stars were indeed being born inside Bok globules.
Known to be some of the coldest objects in the natural universe, observations have revealed that some Bok globules contain embedded warm sources, others contain Herbig–Haro objects, and still others show outflows of molecular gas, a known by-product of the stellar birthing process. Modern techniques including millimeter-wave emission line analysis have provided evidence for the in-fall of material onto accreting protostars. It is now thought that a typical Bok globule may contain up to as much as 10 solar masses of material within its boundaries, and that they most commonly result in the formation of double, or multi-star systems, including open star clusters.
Bok globules are a subject of intense research by professional astronomers; but, the exact nature of their structure and density still remain somewhat of a mystery. Investigative methods applied so far have relied on the study of column density derived from near-infrared extinction. Even the labor-intensive effort of star counting is sometimes used as attempts continue to probe these objects further. As noted elsewhere in this collection, one aspect of the amateur astronomy hobby that it makes so fascinating is knowing that scientific research continues on many objects like Bok Globules that fill our telescopes with strange, fascinating and beautiful objects; even as scientists continue their efforts to improve our understanding beyond the current state of the science.
This object's outer lying dark and dusty clouds are extremely challenging to photograph due to their being so faint. A "fast" telescope (one having a focal ratio of f/4.0 or better) is really needed to capture those faint details and provide the contrast needed to produce a quality image. In response, we chose to call upon outside resources to assist with capturing the sub-frame data. Giving credit where it is due, the "Dreamscope" of Utah Desert Remote Observatories (UDRO) was used. Mr. Craig Stocks, the lead operator of that facility, provided us with a wonderful experience, and exceptional results. His telescope is a 16" FL=1500mm f/3.75 research-quality Newtonian telescope manufactured by Dream Aerospace Systems, Ltd. It has an ASI6200MM-Pro full-frame mono camera mounted on it with Chroma L, R, G, & B broad-band filters; and, it is mounted on a Paramount ME mount with no guiding assist at all. It's an amazing rig! UDRO is located in southwestern Utah at a dark, (Bortle1) location. That location, with its dark skies, its high incidence of clear conditions, reasonably high and dry altitude, and when put together with the fast optics of the Dreamscope, provides perfect conditions to capture images like this one. Once the raw data was acquired, processing was completed using CNP Astronomy's in-house resources. Thank-You's and "Kudos" to Craig and his Team for their help!