Spanning over 3 degrees in the Cepheus constellation (6 full moons), we find an active concentration of gas and dust. The main structure in this complex is known as the Elephant’s Trunk Nebula, IC 1396, an amazing 20 light-years long emission nebulae, located in the Cepheus constellation some 2,400 light years away from Earth.

This color image is the result of combining narrowband filters to map the nebula’s emissions in sulfur, hydrogen and oxygen. Dark patches of nebulosity combine with the colorful emission regions.

To capture this image I combined three narrowband filters following the so-called Hubble Palette that assigns the Red to [SII], the Green to Hα and the Blue to [OIII]. The yellowish areas correspond to the hydrogen and sulfur emissions, while the blueish areas correspond to the oxygen emissions. Surrounding the circular emission nebula we can still see that the sky is now black! Important amounts of gas and dust emit all over this region.

Broadband filters (R, G, B) have been used to capture the star’s colors.

The full image covers an area of 20 full moons (3º44′ x 2º43′) at a resolution of 2.59″/pixel.

Thanks for your time on this website.

Image Details

[SII]: 60 x 300″ (5h)

Ha: 30 x 300″ (2h30′)

[OIII]: 75×300″ (6h15′)

RGB: (15, 15, 15) x 60″ (45′)


Calibrated with darks, flats, dark-flats.


Total exposure: 14h30′


Average Moon phase at 40%

Image resolution: 2.59”/pixel

FOV (full image): 3º44′ x 2º43′


FRA300 + ASI2600MM + LRGB ZWO filters + ZWO EFW 7 pos + ZWO EAF

ZWO AM5 mount


Guiding with ASI120MM and ZWO Mini Guide Scope


ASI Air software, APP, PIX, TPZ, LR, PS.

Aleix Roig, October 2022
Prades (Tarragona, Catalonia – Spain).

error: Image protected by copyright.