NGC6992 Eastern Veil
NGC6992 Eastern Veil
NGC6992 is approximately 1500 light years in the constellation Cygnus. It is a supernova remnant from an exploding about 5000 t0 10000 years ago. When finely resolved, some parts of the image appear to be rope-like filaments. The standard explanation is that the shock waves are so thin, less than one part in 50,000 of the radius, that the shell is visible only when viewed exactly edge-on, giving the shell the appearance of a filament. Undulations in the surface of the shell lead to multiple filamentary images, which appear to be intertwined. Even though the nebula has a relatively bright integrated magnitude of 7, it is spread over so large an area that the surface brightness is quite low, so the nebula is notorious among astronomers as being difficult to see. However, an observer can see the nebula clearly in a telescope using an OIII filter (a filter isolating the wavelength of light from doubly ionized oxygen), as almost all light from this nebula is emitted at this wavelength. An 8-inch (200 mm) telescope equipped with an OIII filter shows the delicate lacework apparent in photographs, and with an OIII filter almost any telescope could conceivably see this nebula. Some argue that it can be seen without any optical aid except an OIII filter held up to the eye. Text from Wikipedia
Fullsize
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Ha 300 min
OIII 300min
SII 420 min
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Scope Planewave 17in
Camera Apogee U16
Mount Paramount ME
Filters Astrodon Ha5nm OIII3nm SII5nm
Exposures Ha 5hrs OIII 5hrs SII7hrs 20min subs
Location Sierra Nevada Mountains CA. Heavens Mirror Observatory SRO 2013