Cave Nebula (Sh2-155)
Distance: 2900 Light Years

Right Ascension: 22:58 (hours : minutes)
Declination: +62:34 (degrees : minutes)


Sh2-155 (popularly known as the Cave Nebula) is a bright rim/HII cloud and star forming region which arose from the large molecular cloud known as Cepheus B. The stars of this region are members of the very young Cepheus OB3 association, one of the nearest OB associations to our solar system. The stars of Cepheus OB3 are very young, mostly less than 100,000 years old. Low mass star formation is occurring at a high rate within Cepheus B and is particularly evident within the dust clouds of Sh2-155. In the image a small pocket of pre-main sequence stars glows from within a dusty cavern of Sh2-155. The two bright stars HD 217061 (west) and HD 217086 (north) (B1 and 07-types respectively) illuminate the bright ridges of Sh2-155.