Celestial hemisphere:  Northern  ·  Constellation: Cygnus (Cyg)  ·  Contains:  NGC 6979
Pickering's Triangle - OSC, Jonathan W MacCollum
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Pickering's Triangle - OSC

Pickering's Triangle - OSC, Jonathan W MacCollum
Powered byPixInsight

Pickering's Triangle - OSC

Equipment

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Acquisition details

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Description

OOTM Entry on /r/ap: https://www.reddit.com/cvnir4/

**Equipment:**

* Orion 8in f4.9 1000mm Flocked / replaced GSO primary mirror

* Guiding with ZWO OAG and asi178mm camera

* ASI071mc one-shot-color cam

* Hutech IDAS LPS D1 Filter

* Celestron CGEM Mount

**Acquisition:**

* Lights:

312x120.0s at -10C on 2019-08-05 and 2019-08-06

* Flats: ceiling flats for each session

* Darks: 60x120s at -10C

* Bias: None

* Bortle Dark-Sky Scale: 4.00

* Pixel scale: 0.981 arcsec/pixel

* Orientation: 0 degrees

* Captured with [N.I.N.A](https://nighttime-imaging.eu/)

**Pre-Processing with PixInsight:**

* Calibrated and stacked using [LVA PreProcessing Steps](http://www.lightvortexastronomy.com/tutorial-pre-processing-calibrating-and-stacking-images-in-pixinsight.html)

* Integrated best 312 of 400 frames selected using a combination of Blink Subframe Selector

Processing Steps:

The processing workflow is summarized with pseudocode for brevity:

```F#

/// Pre Processing

let rgb =

Image Integration

|> Dynamic Crop

|> Dynamic Background Extraction

|> Background Neutralization <| (4 Previews |> Preview Aggregator)

|> Color Calibration

|> Image Solver

|> Photometric Color Calibration

|> RGB Working Space <| (1,1,1)

/// Synthetic Luminance

let l_orig =

rgb

|> extract synthetic luminance

/// Background Noise Reduction

let l_nr =

l_orig

|> Tgvnr // Small Scale Noise Reduction

|> Mmtnr // Large Scale Noise Reduction

/// High-Signal Sharpening

let l_sharpen =

l_orig

|> Deconvolution // 5-layer regularization no deringinging

|> Replace stars <| star mask <| l_orig

|> Mmt sharpen

/// Prepare mask for combining Low-Signal background with High Signal Foreground

let l_combine_mask =

l_nr

|> stf

|> hist stretch cliping whites and blacks

|> blur

/// Combine Low-Signal background with High Signal Foreground

let l =

l_sharpen*l_combine_mask + l_nr *~l_combine_mask

|> curves for contrast enhancement

|> Starnet to produce starless version

|> Additional curves for contrast enhancements with mask protecting bright stars

/// RGB cleanup and combination

let final =

rgb

|> scnr green

|> Tgvnr // Small Scale Noise Reduction

|> Mmtnr // Large Scale Noise Reduction

|> HSV Repair Separation Script

|> Arcsinh Stretch

|> Starnet to produce starless version

|> lrgb combination(l)

|> histogram transfromation

|> local histogram equalization

|> re-add stars from starnet

|> chrominance noise reduction with ATrousWaveletTransform on layers 1-3 of 12

```

* Save as JPEG

Comments

Sky plot

Sky plot

Histogram

Pickering's Triangle - OSC, Jonathan W MacCollum