September 2019 - Picture of the Month
IC 1396 (Elephant’s Trunk Nebula) in Cepheus
This one of my favourite parts of the sky: we have an open cluster (Tr 37) surrounded by the nebulosity of an emission nebula (IC 1396) filled with other interesting objects.
On the periphery lies mu Cephei (Herschel's Garnet Star), a huge red supergiant who's variability can be followed with the naked eye. Personally I see mu Cephei as being more orangy than bright red, but opinions vary, and garnets come in lots of colours.
In the centre are a number of double stars such as STF 2819, and even better STF 2816 which was a Double Star of the Month in October 2015.
Then there's the Elephant's Trunk in the bottom centre of the image above. The tip of this dense gaseous structure hides a group of protostars as imaged by Spitzer. This HII region contains a number of these dark dense regions holding out against the ultraviolet onslaught of the blue supergiant star in the centre of the Tr 37 cluster, just above the tip of the trunk.
I once suspected a little nebulosity visually with the help of a UHC filter, but in retrospect I think it was unlikely under my poor skies. On the other hand Panagiotis' image shows there's a wealth of detail to be found in this nebula with narrowband filters. I think he's achieved a terrific balance between detail and subtle depth; it's very atmospheric. I'll confess that I have imaged IC 1396 with a remote telescope, but nobody's going to see that.
James Whinfrey - Website Administrator.