IC 1396 SHO

The Elephant’s Trunk Nebula is a concentration of interstellar gas and dust within the much larger region of ionized gas IC 1396, located in the constellation Cepheus about 2,400 light-years from Earth. The bright rim of the Elephant’s Trunk is the surface of a dense cloud illuminated and ionized by a very bright massive star (HD 206267) located east of IC 1396A. The entire IC 1396 region is ionized by the massive star, except for dense globules that can shield themselves from the star’s harsh ultraviolet radiation.

According to current understanding, the nebula is a star-forming region containing several very young stars—less than 100,000 years old—discovered in infrared images in 2003. Two older stars (a few million years old) lie in a small round cavity in the head of the globule. Winds from these young stars may have hollowed out this cavity. The combined action of light from the massive star, which ionizes and compresses the cloud’s edge, and winds from the young stars, which push gas outward from the center, leads to a very strong compression of gas in the local area, triggering the formation of the current generation of protostars.