The Elephant’s Trunk nebula is a concentration of interstellar gas and dust within the larger emission nebula IC 1396 located in the constellation Cepheus about 2,400 light years away from Earth. The image shows the dense globule IC 1396A commonly known as the Elephant’s Trunk nebula because of its appearance as a sinuous dark cloud at visible light wavelengths. The bright edge of the cloud is where its surface is being illuminated and ionised by the very bright and massive nearby triple star system HD 206267A.
I acquired the image while testing the Starlight Xpress active optics unit which hopefully will enable me to increase sub-exposures to 30 minutes while operating the APM 152-1200ED telescope at its native focal length of 1,200 mm. Note that the data were acquired under astronomical twilight and first quarter / full moon in June which is a testament to narrowband imaging and Astrodon filters in particular.
Right ascension: 21h 35m 33s | Declination: +57° 25′ 52″ | Distance: 2,400 Light Years
Field of view: 42 x 28 arcmin
Camera: SBIG ST-10XME
Telescope: APM 152-1200ED F/7.9
Guiding: Starlight Xpress Active Optics SXV-LF-AO
Filters: Astrodon Ha (3nm), OIII (3nm)
Exposures: Ha 9 x 20 min, OIII 15 x 20 min
Total exposure: 8 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 1.15 arcsec/pixel
Image acquired: June 2015
Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; Photoshop CS4/CC