A Common Name for the IC 1396 Nebula

June 16, 2017

IC1396_Greg_Noel (2)

Photographer: Greg Parker
Summary Author: Greg Parker

Shown above is the emission nebula IC 1396, which includes the well-known Elephant's Trunk nebula, found in the constellation Cepheus. Oddly, it's one of the largest emission nebulae (HII regions) in the northern skies, but it doesn't have a common name -- it simply has a letter/number designation. This is quite remarkable given that far less imposing emission regions have been christened by astronomers from long ago.

IC 1396 is an immense structure. The dark round patch at its center that you can see in this image is almost the same diameter as a full Moon! Not only is it big, but it also contains many fascinating deep-sky objects, including the open star cluster Trumpler 37. This cluster is one of the youngest star clusters identified in our galaxy. In addition, IC 1396 holds star complex HD 206267, which though it doesn't look overly bright in this visible image, cradles a type of star emitting very strongly in the ultraviolet part of the spectrum (O6.5V) that's mostly responsible for the ionization of IC 1396.

Coming in from the right, just above the 3 o'clock position, we see the bright-rimmed scribble known as the Elephant's Trunk nebula, one of many globules sitting in IC 1396 that are home to star forming regions. Finally, at the top left of the image, we have a star that's difficult to miss; the brightest, reddest, naked-eye star in the Northern skies, Mu Cephei or Herschel's Garnet star (see the EPOD for July 6, 2014 - The Reddest Stars). Although extremely red, Mu Cephei is not a carbon star but is rather a red supergiant star rather like Betelgeuse in Orion.

With so much going on in and around IC 1396, isn't it time that this spectacular object was christened with a popular name? What would you call it?

Image Details: This image is a 2-frame mosaic taken with a Sky 90 refractor telescope and an M25C 6-Megapixel one shot color CCD imager. A total exposure time of 7 hours and 22 minutes in RGB (red, blue, green), and 11 hours and 40 minutes of narrowband H-alpha was devoted to making this image. The data was captured at the New Forest Observatory in Hampshire, the U.K. and was processed by Noel Carboni in Florida, U.S.A.