IC 1396 in Cepheus
The large HII region IC 1396 in the constallation of Cepheus spans some 3 degrees of summer sky. It is illumitated by a single massive O‑type supergiant blue star, located at the center of the donut-shaped emmission cloud.
Seveveral cometlike structures, known as bright rimmed globules, form a loose an slowly espanding ring within IC 1396. Although several of the cometary globules are opticaly conspicuous, the most prominent and well-studied is IC 1396A (bottom), populary kown as the Elephant Trunk Nebula. A detailed image taken with longer focallength can be found here.
Long OIII and Ha data have been combined with Lum to create an enhanced Luminance, which then was blended to a deep RGB to preserve the natural colors. North is at 9 o’clock.
[description from ‘A Year in the Life of the Universe’ by Gendler]