Celestial hemisphere:  Northern  ·  Constellation: Taurus (Tau)  ·  Contains:  10 Hygiea  ·  10.41  ·  11 Tau  ·  11.00  ·  11.96  ·  12.65  ·  16 Tau  ·  17 Tau  ·  18 Tau  ·  19 q Tau  ·  20 Tau  ·  21 Tau  ·  22 Tau  ·  23 Tau  ·  24 Tau  ·  26 Tau  ·  27 Tau  ·  28 Tau  ·  32 Tau  ·  33 Tau  ·  36 Tau  ·  37 A01 Tau  ·  39 A02 Tau  ·  41 Tau  ·  416 Vaticana  ·  44 p Tau  ·  47 Aglaja  ·  52 phi Tau  ·  56 Tau  ·  88 Thisbe  ·  And 43 more.
Molecular Cloud in Taurus: LBN777 with The Pleiades, Jonathan W MacCollum
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Molecular Cloud in Taurus: LBN777 with The Pleiades

Molecular Cloud in Taurus: LBN777 with The Pleiades, Jonathan W MacCollum
Powered byPixInsight

Molecular Cloud in Taurus: LBN777 with The Pleiades

Equipment

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Acquisition details

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Description

So after over a year attempting to shoot this region I've finally completed a revision of the dark molecular clouds that cover the taurus region near the Pleiades. This is but one panel of a larger 8-panel mosaic that I've planned and hope to complete before summer gets here. But this region in particular is one that I am a huge fan of. it is home to the very popular and bright star cluster M45 the Pleiades that sits behind the molecular cloud, but it's radience shines through the dust. Through the dust structures one can find LBN777, a "ghost like" molecular cloud that to my eyes looks like it's about to eat that bright yellow nearby star is more commonly known as the Vulture Nebula or Baby Eagle Nebula.

Also, I've finally launched an early version my own personal website for hosting my images and detailed information over at https://darkflats.com which includes step-by-step processing details with screenshots. Hope to expand on it soon, and that you enjoy the content!

Follow Me on [Instagram](

https://www.instagram.com/jonathanmaccollum/) | [Astrobin](https://www.astrobin.com/users/eigenVector/)

Equipment:

* Celestron CGEM Mount

* Self tuned / hacks to get guiding stable include:

* Intentional offset polar alignment so dec always pulses in one direction



* Balance "west" heavy (rather than the recommended east) so that the ota "falls" onto the gear teeth rather than get "lifted"



* Factor Reset hand-controller daily (to prevent cgem from being possessed and forgetting where the meridian is on subsequent night)



* Dither in RA only

* Rokinon 135mm f2 at f2

* asi071mc PRO at -15 C

* Astronomiks L3 UV/IR filter

* Widefield Rig + AF3 by Deep Sky Dad

Acquisition:

* 123x120s at unity gain (4 hours) taken across four nights in 2019 Dec: 01 - Dec 04. The Moon went from 20%-50% illuminated during these nights but all data taken while moon was below or near the horizon.

All pre-processing and post-processing was done in PixInsight and final touches added with Affinity photo. Full details below.

The resulting image is a combination of the following steps:

* Inspected all subs for bad images with Blink, discarding subs containing clouds

* Calibrated all subs with a master flat and master dark

* Used subframe selector to weight all images based on the following weighting

```C

(10*(1-(FWHM-FWHMMin)/(FWHMMax-FWHMMin))

+ 20*(1-(Eccentricity-EccentricityMin)/(EccentricityMax-EccentricityMin))

+ 30*(1-(Median-MedianMin)/(MedianMax-MedianMin))

+ 10*(SNRWeight-SNRWeightMin)/(SNRWeightMax-SNRWeightMin)

+ 10*(Stars-StarsMin)/(StarsMax-StarsMin))

+ 30

```

* Selected the best sub from subframe and blink to use as a reference frame for aligning and integration

* Cropped the stacking edges of the integrated image

* ![Cropped with Unlinked Screen Transfer Function](/Widefield/Taurus/P3.Step00.Crop.PNG)

* Dynamic Background Extraction

factor](/Widefield/Taurus/P3.Step01.DBE.PNG)

* Background Neutralization using 5 small preview windows aggregated as a background reference

* Color Calibration |> Solved |> Photometric Color Calibration

* RGBWorking Space to 1,1,1

* Noise Reduction was done using TGV Denoise with a low contrast mask and an autostretched local support and MMT with a very protective luminance mask

* Stretched using Arcsinh Stretch followed by Masked Stretch

Luminance Processing

* A synthetic luminance was extracted prior to the stetching of the RGB data for separating luminance processing ``L``

* Stretched using Masked Stretch and Histogram Transformation

* Created a ``Starless`` version of the luminance using [starnet++](https://sourceforge.net/projects/starnet/) and a **StarsOnly** image by subtracting the starless from the luminance ``Starless-L``

* Performed two rounds of Local Histogram Equalization on the starless image

* Kernel Radius 128 | Contrast 4 | Amount 0.100 | 8-bit | Circular

* Kernel Radius 256 | Contrast 8 | Amount 0.030 | 8-bit | Circular

* Performed large scale sharpening and noise reduction with Multiscale Linear Transformation 6 levels

* Recombined the enhanced Starless with the Stars only image with Pixel Math ``Starless+StarsOnly``

Bringing the Enhanced Details back into the Color Data and Final Steps

* Used ChannelCombination in CIE L\*A\*B mode to apply Luminance to Color

* Stars in this image were reduced by using two rounds of morphological selection with a luminance based contours mask created with the following steps:

* Extract a new luminance from the color image

* Apply the following pixel math expression to a new extracted luminance to create a contours version using the ``StarsOnly`` image created earlier: ``StarsOnly/$T-$T``

* Curves transformation was used to increase contrast and saturation with a luminance mask

* Over saturated stars were magenta and were fixed by inverting and applying SCNR green before re-inverting

* An ICC Profile was applied to enable Black Point Compensation

* The image was exported as a 16bit TIFF file and loaded into Affinity Photo

* Final round of noise reduction was applied with Affinity

* HSL enhancements were applied to shift the dust colors to emphasize their golden brown color

* The final image from Affinity Photo and the final image from PixInsight was blended together to ensure a more natural reduction of noise levels

Comments

Sky plot

Sky plot

Histogram

Molecular Cloud in Taurus: LBN777 with The Pleiades, Jonathan W MacCollum