This is my astrophotograph of the large ionised gas region IC 1396, including the Elephant’s Trunk Nebula in the lower right. It is located in the constellation Cepheus about 2400 light years away from Earth. The Elephant’s Trunk nebula, isolated in the image below, is a long winding dark cloud with a glowing edge, illuminated and ionised by the very bright, massive star to the east (on this image, that is to the left). In fact, that bright star is ionising the entire IC 1396 region except for the dense dark globules, which can resist the ultraviolet rays.
I made two versions of this image: a ‘natural-colour’ version (red), and a false-colour version using a kind of ‘pseudo Hubble Palette’. Since I used a one-shot colour (OSC) filter and not narrowband filters, I could not directly create a true Hubble Palette image; however, a ‘pseudo Hubble Palette’ is still possible by carefully mixing channels. For more details, see here. I think that the false-colour version reveals more of the details, even though the colours do not accurately identify regions of SII, OIII and Hα, as they do in a true Hubble Palette image.
- 55× 265-s light frames (Gain 900)
- Full use of calibration frames (darks, flats and dark flats)
- Explore Scientific ED 102 mm Apo f/7 refractor
- Sky-Watcher EQ5 PRO SynScan GOTO equatorial mount
- Altair Hypercam 294C PRO colour fan-cooled camera
- Revelation Adjustable Field Flattener
- Altair quad-band one-shot colour (OSC) 2″ filter
- Altair 60mm guide scope
- Altair GPCAM2 AR0130 mono guide camera