It is also an example of a
cocoon nebula, a term that describes the dusty envelope that surrounds some newborn stars in the process of forming planets.
One of my favorite dark nebulae is Barnard 168, or as I call it, the Road to the
Cocoon Nebula. When I'm hunting for the position of the Cocoon (IC 5146) in my finderscope, I follow this narrow finger of darkness to the emission nebula's telescopic field.
The nebula was round and reminded me a little of the
Cocoon Nebula in Cygnus (IC 5146).
Another well-known imaging target, the
Cocoon Nebula (IC 5146) appeared quite grainy on the standard 5-minute exposure used by Dr Hewitt for all objects, a testimony to this nebula's extreme faintness.
At B168's eastern extremity lies the
Cocoon Nebula, an object too faint for binocular viewing.
Not far from M39 lie the
Cocoon Nebula and the spooky dark nebula Barnard 168, which S&T's Gary Seronik calls "the Road to the Cocoon." Here too is Pi' ([[pi].sup.1]) Cygni, which has one of my favorite preposterous names: Azelfafage ("ah-ZEL-fuh-fahj," a medieval corruption of the Arabic name "the Tortoise").
It's a cinch to follow B168 to its end, which engulfs IC 5146, the
Cocoon Nebula. At first I couldn't see the nebula, but when I added a hydrogen-beta (H[beta]) filter it was immediately apparent, with a 10th-magnitude star at its heart and another at its southern edge.
Another quarry in Cygnus is the 2 [degrees] long Barnard 168, which meanders to and engulfs the
Cocoon Nebula (IC 5146) at its eastern end.