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alan4908

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Everything posted by alan4908

  1. Thanks - I don't think I could have done this without an automated set up. Thanks Martin ! I'm fortunate to live at a location which (by UK standards) has very good dark skies. I'm also at the top of a hill which helps, although it does get rather windy at times.
  2. My image generating productivity has been significantly decreased by the poor UK weather in recent months. Even with an automated observatory, my image capturing has been moving at a glacial rate. However, here’s the latest image to finally emerge from my set up – NGC 7497 NGC 7497 is a spiral galaxy in the Pegasus constellation, approximately 60 million light years distant with a disc size of approximately 91000 light years. The galaxy shows signs of warping indicating past interactions. You can (just) make out some HII regions in the image below that appear to be semi-randomly positioned within the galaxy. The galaxy is viewed away from the plane of our own galaxy, through a mass of dust and gas known as Integrated Flux Nebula (IFN), which resides in our own galaxy and is approximately 600 light years distant. The stars within our galaxy act together in an integrated fashion to faintly illuminate the gas, hence the name. In 1985, the astronomers Magnani, Blitz and Munday (MBM), decided to catalogue the various IFNs and the one shown is known as MBM 54. The image also features many stars and a several background galaxies. Some of the stars are closer to Earth than MBM 54 and appear sharp and distinct (eg the bright blue star at the top, middle) and some are more distant. The more distant objects will therefore appear fuzzy if they are viewed though dust and nebulosity. The LRGB image below represents just under 16 hours integration time and was taken with my Esprit 150. Alan LIGHTS: L:37, R:20, G:20, B:18 x 600s, DARKS:30, BIAS:100, FLATS:40 all at -20C.
  3. alan4908

    NGC6960

    Thanks for the comment Kon ! Alan
  4. alan4908

    Deep Sky III

    Images taken with a Trius 814 and a Esprit 150
  5. alan4908

    NGC6960

    From the album: Deep Sky III

    A second attempt at the Witch’s Broom Nebula (NGC6960), this time in narrowband. It took me 3.5 months to acquire the data, which was caused by a combination of poor UK weather and the partial obstruction by trees at my location. Although imaged in narrowband, I tried to go for realistic looking colours so started with Ha mapped to red and OIII mapped to blue with a synthetic green generated from a Ha/OIII mix. After a few hue adjustments, I ended up with a colour image which mainly gave blue/reddish stars and nebula. I found that detail could be boosted by creating a super luminance image from the individually stacked narrow band stacks and then deconvolving the result which I then blended into the colour result via Pixinsight’s LRGB process. The image represents 16.5 hours integration time.
  6. A second attempt at the Witch’s Broom Nebula (NGC6960), this time in narrowband. It took me 3.5 months to acquire the data, which was caused by a combination of poor UK weather and the partial obstruction by trees at my location. Anyway, better late than never.... Although imaged in narrowband, I tried to go for realistic looking colours so started with Ha mapped to red and OIII mapped to blue with a synthetic green generated from a Ha/OIII mix. After a few hue adjustments, I ended up with a colour image which mainly gave blue/reddish stars and nebula. I found that detail could be boosted by creating a super luminance image from the individually stacked narrow band stacks and then deconvolving the result which I then blended into the colour result via Pixinsight’s LRGB process. The image below was taken with my Esprit 150 and represents 16.5 hours integration time. LIGHTS: Ha: 15, OIII: 18 x 1800s; DARKS:30, BIAS:100, FLATS:40 all at -20C.
  7. alan4908

    NGC 896

    From the album: Deep Sky III

    NGC 896 is an emission nebula located in Cassiopeia about 7500 light years away. It is also the brightest part of the Heart Nebula (IC 1805) but has a separate classification, since it was the first part of the nebula to be discovered. The dominant red colour arises from hydrogen line photon emissions created by intense ultraviolet emissions from nearby stars. It is a star forming region and also home to many dark lanes created by interstellar gas. Some very bright blue stars compete in the nebula illumination, resulting in a blue/red cast in certain parts of the image. The LRGB image has an Ha blend into both the red and lum channel and was taken with my Esprit 150. It represents 18.5 hours integration time.
  8. NGC 896 is an emission nebula located in Cassiopeia about 7500 light years away. It is also the brightest part of the Heart Nebula (IC 1805) but has a separate classification, since it was the first part of the nebula to be discovered. The dominant red colour arises from hydrogen line photon emissions created by intense ultraviolet emissions from nearby stars. It is a star forming region and also home to many dark lanes created by interstellar gas. Some very bright blue stars compete in the nebula illumination, resulting in a blue/red cast in certain parts of the image. The LRGB image has an Ha blend into both the red and lum channel and was taken with my Esprit 150. It represents 18.5 hours integration time. Alan LIGHTS: L:22, R:18, G:11, B:12 x 600s; Ha: 16 x 1800s. DARKS:30, BIAS:100, FLATS:40 all at -20C.
  9. alan4908

    NGC6941

    From the album: Deep Sky III

    Located in the Cygnus constellation about 6000 light years distant, NGC6914 is a blue reflection nebula consisting of VbB131 and VdB132. Surrounding NGC6914 are reddish areas of hydrogen emission nebula which provide a dramatic colour contrast to the blue nebulosity. The contrast is further increased by regions dark nebulosity (LDN 899). The stars are also a notable feature of the image since embedded within the nebula is the star cluster Cygnus OB2 which consists of about 100 class “O” (yellow) and 2500 class “B” (blue-white) stars. The image was taken with my Esprit 150 and represents 16.5 hours integration time. It is an LRGB image with a Ha blend into both the Red and Lum channels.
  10. alan4908

    LBN438

    Thanks for the comment George.
  11. alan4908

    LBN438

    From the album: Deep Sky III

    LBN 438 is a dusty nebula located in the Lacerta constellation which is also known as the sand worm (from the Dune science fiction series) or the shark nebula. It doesn’t appear very often on SGL, probably because it is so faint ! It is illuminated by interstellar radiation known as Extended Red Emission (ERE). ERE is a relatively recent discovery (1975) and is a photo-luminescence process whereby hydrogenated amorphous carbon is illuminated by interstellar photons in the 500 to 1000nm spectral range. Although the nebula also contains ionized hydrogen, it only emits a relatively weak Ha signal, so I decided to only use broadband filters to acquire the target. The LRGB image shown below was captured with my Esprit 150 and represents just over 13 hours integration time. At the top of nebula is a reddish glow, which I presume is due to ERE. The nebula is surrounded by very bright blue stars which can detract from the relatively faint nebula, so these have been stretched much less than the rest of the image and then blended back into the main image. If you look closely at the background you will also be able to see various small background galaxies (eg middle left).
  12. Thanks for the comment Andrew. In terms of the colour balance, I was drawn to change this when I checked the histogram levels which shows that the original image is quite unbalanced at the lower levels, however, I also like the "more blue" effect in the original. I I think the credit for the framing goes to CCDNavigator (where you can preview the image for your given FoV) and ACP, for actually getting the object in the center of the FoV. As an aside, CCDNavigator was recently made compatible with ACP Expert which enables you select objects to image through a view mouse clicks, which I really like. Thanks Paul ! Alan
  13. Hmmm - I decided that the RGB background levels are not optimal on these images and so applied PI Background Neutralization tool to make them a little more balanced.
  14. alan4908

    VdB 152 (annotated)

    From the album: Deep Sky III

    Annotated version of the image VdB 152.
  15. alan4908

    VdB 152

    From the album: Deep Sky III

    In the constellation Cepheus, at 1400 light years from Earth, lies vdB 152, a small blue reflection nebula located at the tip of the dark Bok nebula Barnard 175. Embedded in the dark nebula is the Herbig Haro object HH 450. The faint red streak to the right of the reflection nebula is a supernova remnant known as SNR G110 + 11.3 which appears to be approaching vdB 152. Some of my notes for those that might be interested: Reflection nebulas are created when a nearby star illuminates the gas of at a nebula at an insufficient energy level to ionize the gas but strong enough to create light scattering that makes the dust visible. Reflection nebulas mostly appear blue because particles in the nebula scatter blue light more efficiently than other wavelengths. Bok nebulas are isolated and relatively small dark nebulas containing dense dust and gas from which star formation can occur. Herbig Haro objects are bright patches of nebulosity that form when fast moving narrow jets of partially ionised of gas, ejected from a newly formed star, collide with nearby gas and dust at several hundred km/s. The LRGB image below represents 12 hours integration time and was taken with my Esprit 150.
  16. alan4908

    M100 (reprocessed)

    From the album: Deep Sky III

    A reprocess of my M100 image which is also in this album.
  17. Located in the Cygnus constellation about 6000 light years distant, NGC6914 is a blue reflection nebula consisting of VbB131 and VdB132. Surrounding NGC6914 are reddish areas of hydrogen emission nebula which provide a dramatic colour contrast to the blue nebulosity. The contrast is further increased by regions dark nebulosity (LDN 899). The stars are also a notable feature of the image since embedded within the nebula is the star cluster Cygnus OB2 which consists of about 100 class “O” (yellow) and 2500 class “B” (blue-white) stars. The image was taken with my Esprit 150 and represents 16.5 hours integration time. It is an LRGB image with a Ha blend into both the Red and Lum channels. Alan LIGHTS: L:21, R:17,G:12, B:16 x 600s; Ha:11 x 1800s. DARKS:30, BIAS:100, FLATS:40 all at -20C.
  18. Thanks Glad you liked it - it is a pity that it doesn't appear a little more often here. Thanks Noddy - yes, it is quite amazing what the brain sees when you star at nebula's for a while....
  19. LBN 438 is a dusty nebula located in the Lacerta constellation which is also known as the sand worm (from the Dune science fiction series) or the shark nebula. It doesn’t appear very often on SGL, probably because it is so faint ! It is illuminated by interstellar radiation known as Extended Red Emission (ERE). ERE is a relatively recent discovery (1975) and is a photo-luminescence process whereby hydrogenated amorphous carbon is illuminated by interstellar photons in the 500 to 1000nm spectral range. Although the nebula also contains ionized hydrogen, it only emits a relatively weak Ha signal, so I decided to only use broadband filters to acquire the target. The LRGB image shown below was captured with my Esprit 150 and represents just over 13 hours integration time. At the top of nebula is a reddish glow, which I presume is due to ERE. The nebula is surrounded by very bright blue stars which can detract from the relatively faint nebula, so these have been stretched much less than the rest of the image and then blended back into the main image. If you look closely at the background you will also be able to see various small background galaxies (eg middle left). I hope you like it. Alan LIGHTS: L:31, R:17, G:15, B:17 x 600s; DARKS:30; BIAS:100; FLATS:40 all at -20C.
  20. Thanks - I believe my imaging resolution of 0.7 arc seconds per pixel helps to bring out the details but it also makes imaging capture more challenging, particularly as I image unguided. Alan
  21. Thanks Peter. Thanks for the comment Dave. Hmmmmm..... I had a look in Aladin but cannot see anything marked so I presume it must be a faint reflection nebula, although the shape suggests some form of shock wave. While I can see the object in other images, most scientific attention has been directed towards on the other side of Barnard 175 where the various remnants of the supernova explosion can be seen. Thanks Steve . Thanks - yes, the Esprit 150 is an excellent scope - if anyone is in the market for a large refactor, then it is definitely worth considering, particularly given the price compared to the competition.....
  22. Thanks Adrian ! I'm glad you liked it Paul - and you are correct in that the wide dynamic range of this object makes it a challenge Thanks for the comment. Alan
  23. In the constellation Cepheus, at 1400 light years from Earth, lies vdB 152, a small blue reflection nebula located at the tip of the dark Bok nebula Barnard 175. Embedded in the dark nebula is the Herbig Haro object HH 450. The faint red streak to the right of the reflection nebula is a supernova remnant known as SNR G110 + 11.3 which appears to be approaching vdB 152. Some of my notes for those that might be interested: Reflection nebulas are created when a nearby star illuminates the gas of at a nebula at an insufficient energy level to ionize the gas but strong enough to create light scattering that makes the dust visible. Reflection nebulas mostly appear blue because particles in the nebula scatter blue light more efficiently than other wavelengths. Bok nebulas are isolated and relatively small dark nebulas containing dense dust and gas from which star formation can occur. Herbig Haro objects are bright patches of nebulosity that form when fast moving narrow jets of partially ionised of gas, ejected from a newly formed star, collide with nearby gas and dust at several hundred km/s. The LRGB image below represents 12 hours integration time and was taken with my Esprit 150. An annotated image is also shown. Alan LIGHTS: L:28, R:13, G:14, B:17 x 600s, BIAS:100, DARKS:30, FLATS:40 all at -20C.
  24. Thanks ! Many thanks for your comment Olly.
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