With binoculars or a wide-field scope, this emission nebula is a vast playground, filled with many other interesting objects.
A prominent area of IC 1396 contains the so-called Elephant Trunk Nebula, a long cone of dark nebulosity. Credit: Tony Hallas
One of the largest emission nebulae in the far northern sky can be found in IC 1396, a bright glow in Cepheus that contains several complex objects. Among them are the red supergiant star Mu Cephei; the double stars Struve 2816 and Struve 2819; the dark nebula van den Bergh 142, known as the Elephant Trunk Nebula; dark nebula Barnard 161 (just north of the Elephant Trunk); dark nebulae along its southern border, including B160, B162, B163, and B365; the associated cluster Trumpler 37, which is about 4 million years old; and others.Â
IC 1396 is faintly visible to the naked eye from a truly dark site, and it is large — more than a degree across. It is the scene of a stellar nursery, as is the case with emission nebulae, transforming mostly hydrogen gas into a new generation of suns.
The bright star Mu Cephei glows at 4th magnitude, is slightly variable, and is known as Herschel’s Garnet Star due to its deep ruddy color. It is one of the largest stars known, 1,000 times larger and 100,000 times brighter than the Sun. It lies about 3,000 light-years away, at approximately the same distance as the nebula.Â
From a dark sky site, this area of the Cepheus Milky Way is particularly rich and makes for a wonderful region to scan with binoculars or a wide-field scope.Â
