Wizard Nebula (NGC 7380)
History
The open star cluster was discovered on 7 August 1787 by William Herschels sister Caroline with her 4.2 inch reflector telescope. He observed it later on 1 January 1788 with his large 18.7 inch reflector telescope and cataloged it as VIII 77 (class VIII = coarsely scattered clusters of stars). He noted: «A cluster of coarsely scattered stars, 8' diameter. C. H. 1787» [464] John Herschel observed the cluster and cataloged it as h 2182 (GC 4842), but did not notice any nebula. The cluster was later added as NGC 7380 by Dreyer in his «New General Catalogue». [313]
The H-II region in the star cluster was cataloged by the American astronomer Stewart Sharpless in the 1950s and published as Sh 2-142 in his second edition of the Sharpless catalog in 1959. He noted: «Part of II Cep association. Contains cluster NGC 7380.» He listed Sh 2-143 as a weaker part of the nebula, situated approximately half a degree to the southeast and appearing detached. [310]
Physical Properties
NGC 7380 is a young, open star cluster of the Trumpler type III3pn with stars up to 7th magnitude. [196] The star cluster is shrouded in a galactic nebula (LBN 511, Sh2-142) consisting of red glowing, ionized hydrogen and dark molecular clouds. The nebula was nicknamed «Wizard Nebula».
The distances measured since 2000 are in the range of 1800 pc to 2222 pc (about 5870 to 7250 light years). [145] The age of the star cluster is estimated at 4 million to 12 million years [138, 311] At the centre is the mag 8.58 star DH Cephei (HD 215835), a spectroscopic binary composed of two massive O5-6 stars with an orbital period of 2.111 days. It is late in purifying the surrounding material and may be responsible for the formation of numerous young stars in the surrounding molecular cloud. [312]
| Designation | NGC 7380 |
| Type | OCL (III3pn) |
| Right Ascension (J2000.0) | 22h 47m 21.0s |
| Declination (J2000.0) | +58° 07' 54" |
| Diameter | 20 arcmin |
| Visual magnitude | 7.2 mag |
| Metric Distance | 2.222 kpc |
| Dreyer Description | Cl, pL, pRi, lC, st 9…13 |
| Identification, Remarks | WH VIII 77; h 2182; GC 4842; OCL 244; LBN 511 |
Finder Chart
NGC 7380 is located in the constellation Cepheus at about the extension of ζ Cephei - δ Cephei to the east the same distance. On 3 September it is in opposition to the Sun and crosses the meridian at local midnight. The best observation time is January to December.
