IC 1396

Elephant's Trunk Nebula

The Elephant's Trunk Nebula is a concentration of interstellar gas and dust within the much larger ionized gas region IC 1396 located in the constellation Cepheus about 2,400 ly 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 (HD 206267) that is just to the east 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 Elephant's Trunk Nebula is now thought to be a site of star formation, containing several very young (less than 100,000 yr) stars that were discovered in infrared images in 2003. Two older (but still young, a couple of million years, by the standards of stars, which live for billions of years) stars are present in a small, circular cavity in the head of the globule. Winds from these young stars may have emptied the cavity.

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.

Acquiring and processing details

This data was shot in September 2019. About 277 frames of 60" each unguided. I've reprocessed this data in December 2020 with PixInsight giving a more satisfied result.

  • Magnitude: 3.5
  • Distance: 1.500 - 2.400 ly
  • Apparent size: 12' x 4'
  • Date: September 21 - 2019
  • Integration Time: 4.62 hrs
  • Telescope: TS Photoline 102/715 x 0.79 f5.5
  • Mount: Skywatcher EQ6-Synscan Go-To
  • Camera: ZWO ASI1600MM-c
  • Filters: Ha 6nm, RGB

Acquiring and processing details

This data was taken in August 2021, after a long period of bad rainy weather, the night promised to be a few hours clear. I used my widefield refractor TS61EDPH-II for this to capture it's entire field of view.

  • Date: August 16th, 2021
  • Integration Time: 2.25 hrs
  • Telescope: TS61EDPH-II at f4.5
  • Mount: Celestron AVX
  • Camera: ZWO ASI1600MM-c
  • Filters: 13x300" Ha, 7x300" OIII, 7x300" SII

This is a combined product of two nights. First night August 16th, 2021, as above, the second night October 8th, 2021. To frame my second night I used the previous capture as a reference in N.I.N.A. using the framing wizard.

In total the sequence captured 43x300" Ha, 17x300" O3, and 16x300" S2 with the TS61-EDPH-II and the camera ASI1600MM-Cool. 6.3 hrs of integration in Astro Pixel Processor and post processing in PixInsight.