Urban NGC1499 California Nebula

Here is another urban image taken from my driveway in the light polluted skies of Bedford. This started as a bit of a test shot for my new Zwo ASI2600MC-Pro, but turned out well enough that I'm adding time to the shot. The raw stack background SNR is 33.6 dB and I usually target 42 dB or better. This would require 6.8 times the exposure or 15 hours. I now have most of the calibration files I need, still waiting on a good cloudy day to grab some reasonable flats. The tight crop was due to me taking the camera off the scope and then not matching the  rotation very well with my previous subs when I put it back on the scope. As a result I had to crop out the stacking artifacts.

According to Wikipedia -  The California Nebula (NGC 1499) is an emission nebula located in the constellation Perseus. It is so named because it appears to resemble the outline of the US State of California on long exposure photographs. It is almost 2.5 long on the sky and, because of its very low surface brightness, it is extremely difficult to observe visually. It can be observed with a Hα filter (isolates the Hα line at 656 nm) or Hβ filter (isolates the Hβ line at 486 nm) in a rich-field telescope under dark skies. It lies at a distance of about 1,000 light years from Earth. Its fluorescence is due to excitation of the Hβ line in the nebula by the nearby prodigiously energetic O7 star, Xi Persei (also known as Menkib). The California Nebula was discovered by E. E. Barnard in 1884.

Click on the image to see a higher resolution version, then click again on the image to return to this page. The lower image is a previous processing attempt with less data requiring more noise reduction.


Object NGC1499  Object RA 4:03:18, Dec+36:25:18
Date 3 December 2020 & 1 January 2021
Exposure 150 minutes (10 X 15 minutes)
Conditions Bortle 8 skies, high light pollution levels including an almost full Moon in the sky.
Gain 100
Camera Zwo ASI2600MC-Pro
Optics Prime focus of a  SkyWatcher Esprit 120 f/7 APO refractor with a focal length of 840 mm
Filter Optolong L-eNhance
Location Bedford, Nova Scotia
Processing This image was captured using Sequence Generator Pro, telescope control provided by Mosaic Engine and processed entirely in Images Plus using a split-star process.  Arcsinh stretch, crop and masked noise reduction applied. Sharpening accomplished with a frequency domain high pass filter and deconvolution.  Multi-point flatten used to remove gradient and balance the background.