Object Information

NGC 6960, or the West Veil Nebula, is part of the much larger Cygnus Loop in the constellation Cygnus. The nebula pictured here is a cloud of hot, ionized gas, expanding outward from its source; a supernova explosion that occurred up to 10,000 years ago. (The bright star, 52 Cygni, has no relation to this incident or the nebula itself.)

NGC 6960, also known as the Witch's Broom (or the Finger of God), lies about 1,400 light-years away, and is 35 light-years long. The green-blue colour is due to high oxygen content in that region of the nebula, and the red is due to atomic hydrogen. The separation of colours and asymmetric shape make this nebula a favourite for imaging, though it would appear dim in any telescope.

Due to its energy, this nebula is one of the brightest X-Ray sources in the night sky.

 Image Information

NOTES

I've been having difficulty chasing a good shot of this object for some time. In my most recent reprocessing run, I combined all three nights' worth of data that I took to see if I could bring out some extra detail. Under the Equipment/Data/Location headers, these nights are referred to 1, 2, and 3. Total integration time is 11 hours 40 minutes with an average sensor temperature of 28.1 °C.

EQUIPMENT (1&2)

  • Canon T3i (unmodified)
  • Celestron AVX Mount (Guided: Orion StarShoot, PHD)
  • Skywatcher 80ED (600mm f/7.5)

EQUIPMENT (3)

  • Canon T3i (modified: missing IR cutoff)
  • Skywatcher NEQ6 Pro  (Guided: Orion StarShoot, PHD2)
  • Skywatcher 80ED (600mm f/7.5)

DATA (1)

  • 11x 10min exposures @ ISO-3200 (1h 50min) ~ 24.7 °C
  • 5x Darks
  • 9x Flats
  • 40x Biases

DATA (2)

  • 22x 10min exposures @ ISO-3200 (3h 40min) ~ 28.6 °C
  • 1x Darks
  • 9x Flats
  • 40x Biases

DATA (3)

  • 37x 10min exposures @ ISO-3200 (6h 10min) ~ 31.0 °C
  • 13x Darks
  • 40x Flats
  • 40x Biases

PROCESSING

Processing was done in PixInsight v1.8. The images were calibrated using ImageCalibration and ImageIntegration. The image was split into RGB and L components.

On the RGB image, colour calibration was performed, and the image was stretched. The saturation was increased, and SCNR was used to remove a green overcast, with masking to partially protect the nebula. The black point was reset, and convolution was performed to soften the colour edges.

On the L image, deconvolution was performed, and MultiscaleLinearTransform was used for noise reduction. The image was stretched, and the L and RGB images were combined.

LocalHistogramEqualization was used to enhance some areas of the nebula, and MorphologicalTransformation was used to reduce the intense star presence in the image. MultiscaleLinearTransform was used for slight sharpening, and the black point was reset. CurvesTransformation was used for final contrast and saturation improvements.

LOCATION

Data was collected on the nights of May 28, 2014, May 30, 2014, and September 15, 2015, at the Torrance Barrens Dark Sky Preserve in Ontario, Canada. This is a Bortle 4 site.