Blue Snail nebula in Cygnus, WR 134 Nebula
After noticing this blue shell pop out in my wider field, 200mm, image of this area I was curious to image it up closer. This image was shot almost entirely during the full moon, with the oiii (blue green) shot when the the moon was 78% illuminated. Given those circumstances I am actually astonished I got this much detail. The Ha and Sii filters are near infrared, and though the moon reflects the light of the sun back to us almost perfectly (if you compensate for exposure the colors of a picture taken under full moon will look practically identical to the same image in daylight) the moon does not reflect infra red as well. That's why it is possible to get nice detail with Ha and Sii filters. Oiii is another matter, basically I have avoided using it when the moon is visible. But I used the telescopius website which makes a calculation based on the moons illumination and the distance to the object. It suggested that a moon at 78% illumination and ~80° distance from the object could yield results, and it did! I probably could have captured this in half the time during a new moon, but I have to take clear nights when I can get them. In future I won't discount the presence of the moon as much.
Overview
The WR 134 Nebula—also popularly called the Snail Nebula or the Cygnus Shell—is a faint, nearly circular shell of doubly ionized oxygen (O III) surrounding the Wolf–Rayet star WR 134 in the constellation Cygnus. The bubble is the result of strong stellar winds from the massive, evolved star colliding with surrounding interstellar material.
Central Star
The heart of the nebula is the Wolf–Rayet star WR 134 (also cataloged as HD 191765), a hot, massive star of spectral type WN6. Its intense ultraviolet radiation and powerful stellar winds drive the formation and continued expansion of the surrounding O III shell.
OIII Shell Structure
The nebula forms a roughly circular ring about 1.5° in diameter.
It is dominated by OIII emission, giving it the characteristic teal-blue color captured in narrowband images.
The shell represents a Wolf–Rayet wind bubble—gas swept up by centuries of fast, dense stellar wind colliding with the slower material shed earlier in the star’s life.
Relation to Nearby Nebulae
Lies between the Crescent Nebula (NGC 6888) and the Tulip Nebula (Sh2-101).
Shares the same rich star-forming environment as other Cygnus X emission complexes, though it is physically distinct from them.
Emission Characteristics
Strong OIII signal; very faint Hα emission, making it ideal for narrowband OIII imaging. The contrast between the bright OIII shell and the weaker Hα background highlights the dynamics of a Wolf–Rayet stellar wind bubble.
History & Discovery
First recognized as an OIII shell in the late 20th century through deep narrowband photography and spectroscopic surveys of Wolf–Rayet stars, the WR 134 Nebula became popular among astrophotographers in the 2010s as imaging equipment and narrowband filters improved.
Astrophysical Importance
The nebula offers a clear example of how massive stars shape their environment before ending their lives as supernovae.
Sources for text
*Professional studies of Wolf–Rayet wind bubbles and O III emission shells.
*Narrowband imaging surveys of the Cygnus region (e.g., IPHAS, amateur deep-sky imaging projects).
*Observational data from amateur astrophotographers and large-field astrophotography archives such as AstroBin.
Acquisition
Askar 120APO with .8 reducer: 660mm f/5.5
ZWO ASI533MM Mono Camera at -20C
Guided on ZWO AM5
Chroma filters
10x15s with R,G and B filters
32xHa, 47xOiii, 68xSii @5m
Captured with N.I.N.A. processed with PixInsight, Ps
Blue Snail nebula in Cygnus, WR 134 Nebula
After noticing this blue shell pop out in my wider field, 200mm, image of this area I was curious to image it up closer. This image was shot almost entirely during the full moon, with the oiii (blue green) shot when the the moon was 78% illuminated. Given those circumstances I am actually astonished I got this much detail. The Ha and Sii filters are near infrared, and though the moon reflects the light of the sun back to us almost perfectly (if you compensate for exposure the colors of a picture taken under full moon will look practically identical to the same image in daylight) the moon does not reflect infra red as well. That's why it is possible to get nice detail with Ha and Sii filters. Oiii is another matter, basically I have avoided using it when the moon is visible. But I used the telescopius website which makes a calculation based on the moons illumination and the distance to the object. It suggested that a moon at 78% illumination and ~80° distance from the object could yield results, and it did! I probably could have captured this in half the time during a new moon, but I have to take clear nights when I can get them. In future I won't discount the presence of the moon as much.
Overview
The WR 134 Nebula—also popularly called the Snail Nebula or the Cygnus Shell—is a faint, nearly circular shell of doubly ionized oxygen (O III) surrounding the Wolf–Rayet star WR 134 in the constellation Cygnus. The bubble is the result of strong stellar winds from the massive, evolved star colliding with surrounding interstellar material.
Central Star
The heart of the nebula is the Wolf–Rayet star WR 134 (also cataloged as HD 191765), a hot, massive star of spectral type WN6. Its intense ultraviolet radiation and powerful stellar winds drive the formation and continued expansion of the surrounding O III shell.
OIII Shell Structure
The nebula forms a roughly circular ring about 1.5° in diameter.
It is dominated by OIII emission, giving it the characteristic teal-blue color captured in narrowband images.
The shell represents a Wolf–Rayet wind bubble—gas swept up by centuries of fast, dense stellar wind colliding with the slower material shed earlier in the star’s life.
Relation to Nearby Nebulae
Lies between the Crescent Nebula (NGC 6888) and the Tulip Nebula (Sh2-101).
Shares the same rich star-forming environment as other Cygnus X emission complexes, though it is physically distinct from them.
Emission Characteristics
Strong OIII signal; very faint Hα emission, making it ideal for narrowband OIII imaging. The contrast between the bright OIII shell and the weaker Hα background highlights the dynamics of a Wolf–Rayet stellar wind bubble.
History & Discovery
First recognized as an OIII shell in the late 20th century through deep narrowband photography and spectroscopic surveys of Wolf–Rayet stars, the WR 134 Nebula became popular among astrophotographers in the 2010s as imaging equipment and narrowband filters improved.
Astrophysical Importance
The nebula offers a clear example of how massive stars shape their environment before ending their lives as supernovae.
Sources for text
*Professional studies of Wolf–Rayet wind bubbles and O III emission shells.
*Narrowband imaging surveys of the Cygnus region (e.g., IPHAS, amateur deep-sky imaging projects).
*Observational data from amateur astrophotographers and large-field astrophotography archives such as AstroBin.
Acquisition
Askar 120APO with .8 reducer: 660mm f/5.5
ZWO ASI533MM Mono Camera at -20C
Guided on ZWO AM5
Chroma filters
10x15s with R,G and B filters
32xHa, 47xOiii, 68xSii @5m
Captured with N.I.N.A. processed with PixInsight, Ps