IC 1396

Emission Nebula

Cepheus

RA: 21 39 00.0
DEC: +57 29 24

Diam: 170' x 140'

IC 1396 was discovered photographically by E.E. Barnard in August 1893 using the 6" Cook refractor at Vanderbilt Observatory. The discovery was published in "Photographic Nebulosities and Star Clusters connected with the Milky Way". That, unfortunately, is all information I could find on the internet.

Simbad, oddly, classifies the object principally as an open cluster with a note indicating "Cl+Neb HII". The cluster also bears the designation Trumpler 37. A part of IC 1396 is known as the Elephant's Trunk nebula. Many people therefore call the entire nebula by that name, but strictly speaking this is incorrect. Wolfgang Steinicke lists this part of the nebula as IC 1396 A and Simbad redirects to The Elephant Trunk molecular cloud when queried for that designation. IC 1396 A also bears the designation Sh2-131 and in it lies the YSO (Young Stellar Object) vdB 142, which can be seen as a small reflection nebula. Several dark clouds in (front of) the nebula bear Barnard designations. Here is a map of the region:

Screenshot 2021-10-25 at 11.06.46.jpg

The nebula lies some 2400 lightyears from Earth. The name Elephant's Trunk arises from the visual appearance of the dark nebula IC 1396 A, which seems to resemble the head and trunk of an elephant. The bright star HD 206267 illuminates and ionizes the entire nebula and the rims of the dark globules therein, including the Elephant's Trunk nebula, protect the dust inside the globules from the ultraviolet radiation of that star. In 2003 several very young (~100,000 years old) stars were discovered in IC 1396 A on infrared images. Two slightly older (~ few million years old) stars lie in the head of the globule and their stellar winds may have pushed away the dust there. The combination of the ultraviolet light of HD 206267 and the stellar winds of the two slightly older stars may have triggered the star formation in the globule.

Visually the nebula is a challenge due to its low surface brightness. Many starting observers indicate that they tried to observe the nebula without success. First of all, it is HUGE. Secondly, it isn't very bright. Dark skies and preferably nebula filters are needed to give this nebula a try.

I have one logged observation of the nebula from SQM 21.4 skies in central Spain in August 2016. I make no mention of the cluster nor of the YSO so I should revisit the region some day.

"At 83x very faintly visible without a filter. UHC makes it visible very well. Several dark nebulae are seen in and around it, especially B 161. The brighter edges of the nebula of the Elephant's Trunk are not visible, but I do see the dark lane inside it."

As always,

"Give it a go and let us know!
Good luck and great viewing!"