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alan4908

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Everything posted by alan4908

  1. My first attempt at NGC3718 which lies at a distance of about 49 million light years from Earth. It's a very unusually looking galaxy, featuring a twisted dust lane in the central region. To the right you can also see the companion galaxy NGC3729 which, occurring to radio measurements, appears to be interacting with its larger partner. At the top of the image, Hickson 56 can be seen, a grouping of five small galaxies that are estimated to be about 390 million light years away. The LRGB image represents just under 16 hours and was taken with my Esprit 150. LIGHTS: L: 35
  2. I use the freeware version of FocusMax in conjunction with Maxim DL and ACP Expert and find it gives excellent results, so I've never had the need to get the paid version. The main reason I suggest using FocusMax is that it works out the focusing from a defocused position, which helps to combat the effects of seeing. To further reduce the impact of seeing, I'd also recommend you choose the FocusMax option of convergence which takes (say) 5 exposures at the defocused position and attempts to pick the best one. Seeing will also be minimized by picking a focus star near the zenith, since
  3. alan4908

    NGC5466

    Thanks for the comment Alan
  4. alan4908

    NGC5466

    From the album: Deep Sky III

    Located in the constellation Bootes, approximately 52000 light years from Earth, lies the globular cluster NGC 5466. It is designated as a class XII cluster, meaning that it has relatively non-concentrated stars towards the core compared to a class I cluster. This last fact starting me wondering if my scope would be able to resolve the "gaps" in the central core...... note also the various background galaxies. The LRGB image below was taken with my Esprit 150 and represents just over 9 hours integration time.
  5. alan4908

    IC410

    From the album: Deep Sky III

    My first attempt at the Tadpole Nebula (IC410). Located in the Auriga constellation, the nebula is about 12000 light years distant and is approx 100 light years across. The red tadpole like objects are believed to be about 10 light years across and consist of dust and gas that have been shaped by stellar winds. The nebula also contains an open cluster (NGC1893) that contains newly born stars that are estimated to be only 4 million years old (in the center of the image and a little to the right). Since I prefer natural looking colours, on the acquisition side, I decided to go for
  6. alan4908

    M37 (2020)

    From the album: Deep Sky III

    The open cluster M37 contains almost 2000 stars and is spread across 20 light years. Most of the stars are young blue/white but it also contains red giant orange suns which provide considerable colour contrast. I first imaged M37 a couple of years ago but I decided to add to the data since I was never entirely happy about the quality of the some of the sub-frames. I also decided to try out some of my newly learnt stellar processing techniques to improve the data which I describe below for anyone that might be interested. Since I often image in non-ideal conditions, I sometimes find tha
  7. SH2-115 is a faint emission nebula in the Cygnus constellation about 7500 light years distant. It is normally imaged in narrowband, however, since I prefer natural looking colours, I went for a LRGB composition with an Ha blend into the red and lum channels. The image below represents about 17 hours and was taken with my Esprit 150. I encountered an interesting challenge in the processing stage of the above image in that I discovered that I had also acquired high levels of scattered light from an out of field star. These rays appeared in all the Lum, Red and Green subframes.
  8. Hi Brian Thanks for the comment Yes, I find it amazing how amateur equipment can capture such faint and distant objects in such detail. I guess it is primarily due to the advances in digital cameras and digital signal processing. Alan
  9. Located in the constellation Bootes, approximately 52000 light years from Earth, lies the globular cluster NGC 5466. It is designated as a class XII cluster, meaning that it has relatively non-concentrated stars towards the core compared to a class I cluster. This last fact starting me wondering if my scope would be able to resolve the "gaps" in the central core...... note also the various background galaxies. The LRGB image below was taken with my Esprit 150 and represents just over 9 hours integration time. Alan LIGHTS: L:12, R:17, G:10, B:17 x 600s, DARKS:30, B
  10. Thanks for your comments Dave. The LRGB image was improved by my first attempt at creation of a super luminescence (a noise weighted result of the individual L, R, G, B stacks - my RGB data is binned 1 x 1 so, it increases SNR without decreasing detail). Thanks Goran Thanks Alan ! - apart from the superlum creation (mentioned above) I was also experimenting with a couple of new PI techniques that I also recently learnt from Adam Block's PI tutorials ( https://adamblockstudios.com/) - the first was to boost nebula contrast via the fuzzy logic script (LocalFuzzyHistogramHyperbol
  11. Thanks Alan. Yes - it seems a very good target with my field of view, I was also somewhat pleased on the tadpole details. Thanks for the comment Alan
  12. My first attempt at the Tadpole Nebula (IC410). Located in the Auriga constellation, the nebula is about 12000 light years distant and is approx 100 light years across. The red tadpole like objects are believed to be about 10 light years across and consist of dust and gas that have been shaped by stellar winds. The nebula also contains an open cluster (NGC1893) that contains newly born stars that are estimated to be only 4 million years old (in the center of the image and a little to the right). Since I prefer natural looking colours, on the acquisition side, I decided to go for
  13. Thanks for the comment Adam Alan
  14. Thanks Adrian Thanks
  15. The open cluster M37 contains almost 2000 stars and is spread across 20 light years. Most of the stars are young blue/white but it also contains red giant orange suns which provide considerable colour contrast. I first imaged M37 a couple of years ago but I decided to add to the data since I was never entirely happy about the quality of the some of the sub-frames. I also decided to try out some of my newly learnt stellar processing techniques to improve the data which I describe below for anyone that might be interested. Since I often image in non-ideal conditions, I sometimes find tha
  16. I had a look at your data and used Pixinsight and Photoshop to process the result (below). As you can see you've captured quite a lot of detail. On the vignetting issue this seems to be mainly in the RGB data, your Lum data is much flatter. I eliminated both with the use of Pixinsight's DBE function - you can do a similar function in PS but you will require the use of the plug-in Gradient Xterminator. I also noticed that your lum data is very slightly misaligned with the RGB data, so I realigned this to get better stellar profiles. Alan
  17. alan4908

    Apr297

    Thanks for the comment ! Alan
  18. alan4908

    NGC4216

    From the album: Deep Sky III

    The galaxy NGC4216 is in the Virgo Cluster about 55 million light years from Earth. It is shown in the center of the LRGB image below with two main companions NGC4206 (top) and NGC4222 (bottom). Also displayed are a few background galaxies. The inclination of NGC4216 is 89 degrees so, it is almost edge on, making the revelation of dust lanes difficult, so I was quite pleased that I managed to capture a few details. The image represents 12.5 hours integration time and was taken with my Esprit 150.
  19. alan4908

    Apr297

    From the album: Deep Sky III

    Here's one you don't see often: - Arp297 which consists of four galaxies NGC5752, NGC5753, NGC5754 and NGC5755 all of which are located in Bootes. NGC5754 and NGC5752 are approx 200 million light years distance whilst NGC5753 and NGC5755 are much further away, at approx 450million light years. The more distant galaxies don't appear to be interacting now, although the extended arms of NGC5755 indicate that an interaction may of occurred in the distant past. By contrast, a gravitational interaction of the closer two galaxies has produced an extremely long (275,000 light years) tidal t
  20. alan4908

    IC1848

    From the album: Deep Sky III

    A close up of the open star cluster IC1848 which is embedded within the Soul Nebula (Westerhout 5). The LRGB image represents just over 21 hours integration time and was taken with my Esprit 150. To capture the detail of the emission nebula, I gave it an Ha blend into both the Lum and Red channels.
  21. alan4908

    NGC3938

    From the album: Deep Sky III

    The Galaxy NGC3938 is located in the Ursa Major Cluster and is approximately 60 million light years from Earth. It has a large number of H II regions showing as pinkish regions on the LRGB image below. The galaxy doesn't seem to be often imaged, which perhaps is because it is relatively small, with an apparent size of 5.4 x 4.9 angular minutes. The image below represents just over 13 hours integration time and was taken with my Esprit 150.
  22. Hi Vlad I thought you might be interested in seeing the Pixinsight screen show (below) which I've taken with the cursor hovering over part of the green blob located at x= 51 and y = 40. The image is after I've performed DBE but before any PCC. This shows what happens to the linear RGB values as they are put through the non-linear stretching function (called Histogram Transformation in Pixinsight). So, for example, the red value before the stretch is 0.0066 and goes to 0.48 when it is stretched. If you make a table of the values you get: DBE (linear)
  23. Here's some documentation of the Pixinsight Photometeric Color Calibration tool which might help answer your question: https://pixinsight.com/tutorials/PCC/index.html I presumed this was the consequence of the various non-linear operations performed between the linear to the final processed state. Alan
  24. If I look at the data at the stages after Pixinsight's DBE (image is linear), Photometric Colour Calbibration (image is linear) and the Final (LRGB non linear) I get these RGB values: DBE PCC Final R 0.00664 0.00679 0.40200 G 0.00707 0.00727 0.64300 B 0.00683 0.00679 0.62000 RGB ratios with R normalized to unity
  25. Thanks for the response Adam and highlighting more green blobs...However, I'm still somewhat puzzled about what these green blobs actually are. Alan
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