230719 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=EB Driveway BrtlCls=5 moon=3%, WxCr exposure=CMOS OSC; 180x180s (9.0h) EQUIPMENT: camera=ZWO ASI2600MC-Pro optics=ES102 w1.0x fltnr, FL=714mm, f/7 filter=Optolong L-Pro LPS mount=Celestron AVX guiding=Orion 60x240mm wZWO ASI224MC SOFTWARE: acquisition=Stellarium, APT, PHD2, processing=PixInsight, RCAstro, PhotoshopCC, Lumenzia, APF-R, 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 name is easily understood. Scientifically, the formation is referred to as a Bok Globule, and measures over 2 light-years across. There are several stars embedded, whose reflected light make the nebula appear 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 typically contain molecular hydrogen (H2), carbon oxides and helium, and silicate dust.
Bok globules were first observed by Dutch-American astronomer Bart Bok in the 1940s. In an article published in 1947, he hypothesized that these clouds were "similar to insect's cocoons" that were undergoing gravitational collapse to form new stars, from which stars and star clusters were born. This hypothesis was difficult to verify due to the observational difficulties of establishing what was happening inside a dense dark cloud that obscured the visible light emitted from within it. An analysis of near-infrared observations published in 1990 confirmed 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, some contain Herbig–Haro objects, and still others show outflows of molecular gas. Studies including millimeter-wave emission lines have provided evidence for the in-fall of material onto an accreting protostar. It is now thought that a typical Bok globule may contain up to about 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, their structure and density remain somewhat of a mystery. Investigative methods applied so far have relied on column density derived from near-infrared extinction, and even star counting as attempts continue to probe these objects further.
Looking at this image, the nebula's name is easily understood. Scientifically, the formation is referred to as a Bok Globule, and measures over 2 light-years across. There are several stars embedded, whose reflected light make the nebula appear 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 typically contain molecular hydrogen (H2), carbon oxides and helium, and silicate dust.
Bok globules were first observed by Dutch-American astronomer Bart Bok in the 1940s. In an article published in 1947, he hypothesized that these clouds were "similar to insect's cocoons" that were undergoing gravitational collapse to form new stars, from which stars and star clusters were born. This hypothesis was difficult to verify due to the observational difficulties of establishing what was happening inside a dense dark cloud that obscured the visible light emitted from within it. An analysis of near-infrared observations published in 1990 confirmed 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, some contain Herbig–Haro objects, and still others show outflows of molecular gas. Studies including millimeter-wave emission lines have provided evidence for the in-fall of material onto an accreting protostar. It is now thought that a typical Bok globule may contain up to about 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, their structure and density remain somewhat of a mystery. Investigative methods applied so far have relied on column density derived from near-infrared extinction, and even star counting as attempts continue to probe these objects further.