Nebulae represent clouds of gas and dust which appear as hazy or fuzzy objects when viewed through a telescope and are
characterized as one of four types (emission, planetary, reflection or dark). Emission nebulae, such as the Lagoon
nebula (M8), simply glow, for example, with a stunning shade of red. Planetary nebulae appear as small greenish disks
through a telescope, thus emulating the planets Uranus and Neptune, as a result of gas masses being thrown off by dying
stars (ex. M27, Dumbbell nebula) or represent supernova remnants (ex. M1, Crab nebula). In contrast, reflection nebulae
are characterized with gas surrounding young stars which reflect the stellar light (ex. M45, Pleiades) and, thus, yield
beautiful images of nebulosity. Finally, dark nebulae are detectable and studied only using parts other than the visible
spectrum and are believed to be associated with the formation of stars (ex. M16 in Serpens).
Note: The stunning Cocoon Nebula in Cygnus has the distinction of being an emission, reflection and absorption nebula as characterized by its rich plethora of red and blue hues as well as dark lanes when viewed in the visible portion of the spectrum. IC 5146 is technically a star cluster owing to the presence of a developing open but loose cluster at the heart of this rich nebulosity and which is evident in the image below. Widefield photos of the region reveal a Barnard dark nebula (B168) which terminates with the Cocoon nebula. This stellar nursery lies at a distance of 4,000 light-years away and is located a few degrees south of the open cluster M39. The dark nebula B168 which terminates to the east at the Cocoon nebula can easily be detected using binoculars.
Please click on the image below to display in higher resolution (1200 x 900)
OCL 213, LBN 424
III 2 p n
RA / Dec:
21h 53m 24s /
47° 16' 00"
10' x 10'
Aug 13-14, 2007
22:30 - 03:15 UT+3
AP 160 f/7.5 StarFire EDF
AP 1200GTO GEM
SBIG LRGB + IR-block