Urban Heart of the Heart Nebula

Here is another urban image taken from my driveway. The conditions were less than perfect with very poor seeing and a slight haze that made for a very bright sky. An Optolong L-enHance light pollution filter was used for this image to get as much narrow band H-alpha detail as I could given the conditions. Because of the way the filter affects the colour of the image a fair amount of the processing went into getting natural star colours and to prevent the monochrome red look. There is quite a bit of detail in this one so it is worth clicking on the image to zoom in and look around.

According to Wikipedia - The Heart Nebula, IC 1805, Sharpless 2-190, lies some 7500 light years away from Earth and is located in the Perseus Arm of the Galaxy in the constellation Cassiopeia. It was discovered by William Herschel on 3 November 1787. It is an emission nebula showing glowing ionized hydrogen gas and darker dust lanes.

The brightest part of the nebula (a knot at its western edge) is separately classified as NGC 896, because it was the first part of the nebula to be discovered. The nebula's intense red output and its morphology are driven by the radiation emanating from a small group of stars near the nebula's center. This open cluster of stars, known as Collinder 26 or Melotte 15, contains a few bright stars nearly 50 times the mass of our Sun, and many more dim stars that are only a fraction of our Sun's mass.

Click on the image to see a higher resolution version, then click again on the image to return to this page.

Object IC1805 The Heart Nebula  Object RA 2:33:22, Dec +61:26:36
Date 12 October, 2020
Exposure 3 hours (12 X 15 minutes)
Conditions Bortle 7 skies, high light pollution levels, very poor seeing with slight haze..
ISO 1600
Camera Canon 60Da DSLR
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.  Initially an arcsinh stretch was used to brighten the image enough to see where to crop. The image was cropped then a starless mask made using the feature mask tool. The image was split into star and DSO layers using the feature mask and the DSO layer was noise reduced using a large radius, selective neighbourhood detail preserving filter applied with a mask to limit the amount of blurring applied to the nebula. The background was further smoothed using a frequency domain lowpass filter. The stars were then recombined with the noise reduced nebula image and another stretch was applied using the starless mask made after the first stretch. A slight star reduction was applied to bring the nebula out a little more without additional stretching. Several iterations of sharpening were applied at various image scales with appropriate masks to target specific areas of the image. Curves were used to set the contrast and the image was binned by two for web download.