Sh2-155 is a compact H II region in the constellation of Cepheus, located about 2,400 light-years away. It forms part of the Cepheus B molecular cloud, one of the most active star-forming regions associated with the Cepheus OB3 stellar association.
Spanning roughly 35 light-years, the nebula is ionized primarily by the intense ultraviolet radiation from the massive O7V star HD 217086. Its powerful stellar wind and radiation sculpt the surrounding molecular cloud, creating the characteristic dark cavity that gives the object its popular name, The Cave Nebula.
Sh2-155 is only one part of the much larger Cepheus B star-forming complex, which also includes Sh2-156, Sh2-157 and the nearby reflection nebula NGC 7129, revealing different stages of stellar birth within the same giant molecular cloud.
ZWO AM5
TS Optics 94EDPH f4.4
ZWO ASI2600MM Pro
Baader LRGB
Antlia EDGE Ha 4.5nm
35h total exposure
Bortle 4