Celestial hemisphere:  Northern  ·  Constellation: Draco (Dra)  ·  Contains:  FI Cep  ·  HD198737  ·  HT Cep  ·  HU Cep  ·  HW Cep  ·  LBN 468  ·  LBN 483  ·  LDN 1147  ·  LDN 1148  ·  LDN 1152  ·  LDN 1155  ·  LDN 1157  ·  LDN 1158  ·  PGC 2708838  ·  PV Cep  ·  V0335 Cep  ·  V0336 Cep  ·  V0448 Dra
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LBN 468, Two Reflection Nebulae, Alan Brunelle
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LBN 468, Two Reflection Nebulae

Revision title: LBN 468 Revision

Getting plate-solving status, please wait...
LBN 468, Two Reflection Nebulae, Alan Brunelle
Powered byPixInsight

LBN 468, Two Reflection Nebulae

Revision title: LBN 468 Revision

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Description

Revision 1/3/2023: 
Still another revision using the newer functions now available.  Here I tried to remain close to faithful of the original image dynamic range.  However, it is a bit brightened and a somewhat greater dynamic range is achieved.  I can see more of the faint molecular clouds, while still retaining some of the darkest background of the Universe beyond.  This only possible with the new functions.  Or at least in my hands!  As seen for previous revisions of some of my other posts using these methods, I can certainly tease out more details on the fine scale.  The original image, which is retained, was beginning to suffer from posterization effects around the brighter reflection nebulae.  Not a huge problem at normal scale, but if there is more to be had, they why suffer with posterized images?  Also fixed the stars from edge effects of backspacing, etc.  I am posting a revised starless image since this clearly illustrates improved image clarity even in the dust regions.  I have come to a best approach of star fix, noise reduction and image sharpening.  It is a little more work than what I have seen others claim to use, but I have learned that some features, while designed to work together as a single button push, yield poor results.  While probably not noticable at normal scale, it bugs me to lose any details at any scale.  Yes I expect that these images will be viewed at a reasonable magnification, if I did not care about the details, I wouldn't be breaking my back using 11 and 12 inch telescopes.

Original Description:
Not too much to be said about this dark nebula, which is a continuation of my targeting dust in the Cepheus region. LBN 468 rises just ahead of NGC 7023, the Iris, and likely is part of the same complex of clouds and reflection nebulae. The two small ones here are evidently illuminated by single stars visible in this image. Both are identified on the plate solve. This field of view is entirely filled with dust, though with highly variable densities. In some places dense enough to completely block light from any stars behind them. Yet there are numerous very small galaxies that can be seen through the less dense regions.

I am adding the StarNet++ image of this because StarNet actually did a very good job this time and to demonstrate the full extent of the dust. I did not massage the starless image so there are a

couple of the brighter, larger stars that left their mark. However, the starless image particularly highlights the reflection nebulae and if you look closely it captures some of the galaxies as lighter tiny smudges! So congratulations on that capability!

My incremental tweaking of my backspacing took a slight turn for the worse on this, so will need to back it out just a hair. It is amazing how sensitive this setup is to slight adjustments! Once done, then I will deal with the slight tilt. I could have spent a night dealing and solving this issue, but with so few nights to image and such short nights, I would rather image than get my edge stars just perfect.

For QHY268C users, I used the High Gain capture mode at a gain of 60, offset of 12. This offers the lowest read noise. I also solved the raster line issue I had from a couple of months ago. It turns out that the lines were not a result of my using low offsets, but rather is a function of the USB setting. I bumped that up to 20 and away they went! Would be nice if QHY actually told me that. In any case, I can't complain about the signal I am getting with 90 sec subs...

Comments

Revisions

  • LBN 468, Two Reflection Nebulae, Alan Brunelle
    Original
  • LBN 468, Two Reflection Nebulae, Alan Brunelle
    C
  • LBN 468, Two Reflection Nebulae, Alan Brunelle
    D
  • Final
    LBN 468, Two Reflection Nebulae, Alan Brunelle
    E

C

Title: LBN 468, starless

Description: Replaced old starless version with the new. Improvement was much more significant with the latest StarXTerminator in PI. No additional improvements to the image were made.

Uploaded: ...

D

Title: LBN 468 Revised Starless

Uploaded: ...

E

Title: LBN 468 Revision

Description: See updated Description for details.

Uploaded: ...

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LBN 468, Two Reflection Nebulae, Alan Brunelle