The Elephant's Trunk nebula is a concentration of interstellar gas and dust in the star cluster IC 1396 – an ionized gas region located in the constellation Cepheus about 2,400 light years away from Earth.
The piece of the nebula shown here is the dark, dense globule IC 1396A; it is commonly called the Elephant's Trunk nebula because of its appearance at visible light wavelengths, where there is a dark patch with a bright, sinuous rim.
The bright rim is the surface of the dense cloud that is being illuminated and ionized by a very bright, massive star that is just to the west of IC 1396A. The entire IC 1396 region is ionized by the massive star, except for dense globules that can protect themselves from the star's harsh ultraviolet rays.
The combined action of the light from the massive star ionizing and compressing the rim of the cloud, and the wind from the young stars shifting gas from the center outward lead to very high compression in the Elephant's Trunk nebula. This pressure has triggered the current generation of protostars.
Telescope: APM Astrograph 107, f/6.5 with Baader Steeltrack Focuser and 2.5'' TS FF
Mount: NEQ6 Pro with EQ Mod and XBOX Wireless Controller
Camera: ATIK 314L+
Image Scale: 1.91 arcsec/pixel
Filter: Baader Ha 7nm, Baader R,G,B, IDAS LPS
Filter Wheel: Starlight Xpress Motor USB, 7x1.25''
Guide Camera: QHY5 with PHD Guiding and TS UV/IR Block
Guide Scope: Skywatcher Finderscope 8x50
Total Exp. Time: 4 hours, Ha: 150 min (bin 1x1), R,G,B: 30,30,30 min (bin 1x1)
Temperature: Ambient (13C), CCD (-5C)
Capture: Nebulosity 2.3.0
Register, Stack: Maxim DL, CCD Stack
Processing: Photoshop CS3
Date: 10 June 2011
Location: Ag. Panteleimon, Attica, GR
