IC1396 is an open cluster with associated nebulosity, located in the constellation of Cepheus, some 2400 light years away. It is seen with bright Ha emissions & dark dust lanes, some of which are concealing young proto stars. Within the cluster there are 2 nebulae designated IC1396A & IC1396B. The A part is also called the Elephant Trunk nebula and can be seen upper right in the image below; part B is beyond the base of the ‘trunk’. These regions are areas of dust & gas where star birth is ongoing. My image below is of the central part of IC1396 …
Click image for a larger view or look in my astrogallery
Canon 300D modified
Canon 500mm f4 L IS plus 1.4 extender giving 700mm @ f5.6
Astronomik UHC filter
46 x 3 minute sub exposures @ ISO1600 – Total Exposure 2hrs 18 mins
Celestron CG5 mount
Guiding: SXpress Lodestar & PhD Guiding
Processing: Iris, Photoshop, Lightroom
Conditions: variable due to mist & moving clouds. Full Moon.
The Elephant’s Trunk shape is caused by the action of a large ionising double star (SAO33626 seen beneath it in the picture above) and the opposing winds from young stars within the trunk. The 2 actions are compressing interstellar gases into the rim of the nebula.
At the bottom left of the image, the ‘Garnet’ star Mu Cephei can just be seen. This is one of the largest stars that we have so far observed, having a radius almost 1500 times larger than that of our sun. The Garnet star (HIP 107259) has a variable magnitude of 4 to 5 and is 5260 light years from Earth. To put the size of this star in perspective, if replacing our sun, its outer edge would be somewhere around Saturn. It is doomed in time to explode as a substantial supernova.
If you have WorldWide Telescope, click here to view the whole of IC1396.