NGC 7380, Sh2-142
Distance: 10,400 Light Years

Right Ascension: 22 : 47.0 (hours : minutes)
Declination: +58 : 06 (degrees : minutes)

text copyright Robert Gendler 2006

Some open clusters are imbedded within nebulosity and may even illuminate a bright HII region. NGC 7380 in Cepheus represents a bright grouping of predominantly O and B type stars imbedded in the HII region Sh2-142. The cluster stars have their origin in the Cepheus OB1 association and the complex of cluster and nebula are part of an even larger and optically invisible molecular cloud designated NGC 7380E. Star formation began some 4 million years ago creating NGC 7380 and continued for another 2 million years before it ceased. The cloud became ionized by the bright eclipsing binary HD215835 (DH Cephei) ultimately creating the HII region Sh2-142. DH Cephei is the moderately bright star near the center of the nebula in the image. The structure of the HII cloud has a distinctive form with interlaced bright rims and arc shaped dust lanes. The configuration of nebula and the abrupt end of the molecular cloud at its border suggest that Sh2-142 is a blister shaped ionization front seen edge-on along the border of its molecular cloud. Sh2-142 occupies an area of about 140 x 75 light years and is located 10,400 light years from our sun. Its ancestral molecular cloud, the NGC 7380E complex contains some 6000 to 15,000 solar masses.