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alan4908

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Everything posted by alan4908

  1. 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.
  2. From the album: Deep Sky III

    Annotated version of the image VdB 152.
  3. 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 l
  4. alan4908

    M100 (reprocessed)

    From the album: Deep Sky III

    A reprocess of my M100 image which is also in this album.
  5. 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 an
  6. 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....
  7. 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
  8. 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
  9. 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, parti
  10. 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
  11. 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 l
  12. Thanks ! Many thanks for your comment Olly.
  13. Thanks - I don't often reprocess but I'm pleased that this time. Thanks for the comment. Many thanks Dave.
  14. I decided to reprocess my M100 data from last year. This time, I decided to present the image in a much wider field of view, which has the benefit of highlighting the various background galaxies. The other notable changes are that the blue spiral arms are emphasized more and the overall brightness of the central galaxy has been increased. At just over 12 hours integration time, this was taken with my Esprit 150. Alan The original version is here:
  15. alan4908

    LDN982

    From the album: Deep Sky III

    The dark nebula LDN982. The LRGB image represents 15 hours integration time.
  16. I use NoMachine https://www.nomachine.com/ and actually prefer it over TeamViewer. Alan
  17. Thanks Yes, I really do like my Esprit 150 - given the quality, I think it represents excellent value for money. Alan
  18. My second processing attempt at the dark nebula LDN981. This time, I decided to try a more traditional LRGB rendition and so excluded the Ha I had also acquired. The image below represents 15 hours integration time and was taken with my Esprit 150. Alan LIGHTS: L:29, R:20, G:18, B:23 x 600s;. DARKS:30, BIAS:100, FLATS:40 all at -20C.
  19. alan4908

    M94

    From the album: Deep Sky III

    M94 is approximately 17 million light years distant and contains both inner and outer rings. Star formation occurs in both rings but is mainly concentrated in the inner ring which is also known as a starburst ring, within this region, the rate of star formation is occurring so fast that it will exhaust the available interstellar gas supply well before the death of the galaxy. The extensive outer ring contains about 20% of the galaxies mass and consists of spiral arms when viewed in IR/UV, however, in visible light it appears as a halo. Exactly how the outer ring formed is subject to debat
  20. My first attempt at LDN981, a dark cloud nebula located in Cygnus. I decided to try to make the image a little more colourful than the conventional rendition by capturing 10 hours of Ha data which I subsequently blended into the Red and Lum channels. This significantly increased the red parts of the image and the definition of the dark dust lanes, see below. At the bottom left on the image, an interesting object can be seen (Herbig Haro 389). This is revealed as a blue/red angular shock wave which has been created by a fast moving jet of partially ionised gas, which has been ejecte
  21. alan4908

    vdB1 (annotated)

    From the album: Deep Sky III

    Annotated version of the vdB1 image showing the location of several several herbig-haro (HH) objects. HH objects are bright patches of nebulosity which are created when high speed partially ionised gases ejected by stars collide with nearby gas and dust.
  22. alan4908

    vdB1

    From the album: Deep Sky III

    VdB1 is a small reflection nebula in the Cassiopeia constellation. It's approximately 1600 light years distant and about 5 light years across. It consists of dust and gas which are illuminated by bright nearby stars. The scattered light from these stars appears blue since scattering is greater at shorter wavelengths. Another interesting object within the field of view, is a somewhat strange looking looped nebula. This is an example of star formation and several herbig-haro (HH) objects are also located in this vicinity. HH objects are bright patches of nebulosity which are created
  23. If you end up with an integrated image that you are not happy with, you could also try realigning all the subs again but this time with the frame adaption option checked in the Star Alignment process. This option makes PI perform a linear fit of individual sub frame with respect to the reference frame. This option is recommended if you have large intensity variations from the different data sets. These intensity variations might come from a different camera, different camera angle etc.
  24. Thanks - yes, I agree about the appearance, it does look odd. In fact, everything about this galaxy seems a little strange and mysterious. Alan
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