Crescent Nebula Region

I absolutely love the milky way region in Cygnus! It is rich in open clusters and spectacular nebulae.

Since my last post I've acquired a wide field refractor to be able to capture a wider field of view. It brings me the most joy to see the astronomic diversity in seeing so many different things going on in one picture.

About the Crescent Nebula

The Crescent Nebula (NGC 6888) is a 25-light year wide emission nebula in the constellation Cygnus. This “cosmic bubble” in space owes it's striking appearance to a central Wolf-Rayet star that pushes the hydrogen and oxygen atoms outward. 

-  https://astrobackyard.com/ngc-6888-crescent-nebula/ 

The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. 

- https://apod.nasa.gov/apod/ap160610.html

Constellation: Cygnus

Image Center RA = '20 14 14.527'

Image Center DEC = '+38 44 19.335' 

Distance: ~ 5,000  lys

Magnitude: 7.4

Hubble Palette

RGB with Ha added

RGB

Ha

CAPTURE INFO

-------------------

Scope Centering:

Image Center RA = '20 14 14.527'

Image Center DEC = '+38 44 19.335' 

Bandwidths:

R, G, B, Ha

Bias: Yes

Darks: Yes

Flats: Yes

Flat Darks: Yes

Dates Captured:

August 4, 2021

August 13, 2021

August 14, 2021

August 15, 2021

August 16, 2021

GUIDING NOTES:

excellent, averaging ~0.7 RMS

EQUIPMENT

Optics: 

William Optics ZenithStar 61ii Doublet Refractor @ 360mm FL

William Optics Adjustable Field Flattener 61A for Z61

Camera: ZWO 294mm Pro (mono)

Filter Wheel: ZWO 8 position, .36" filters

Filters: 

 - L (Baader Planetarium LRGB 36 mm Round CCD Filter )

 - R (Baader Planetarium LRGB 36 mm Round CCD Filter )

 - G (Baader Planetarium LRGB 36 mm Round CCD Filter )

 - B (Baader Planetarium LRGB 36 mm Round CCD Filter )

 - Ha (ZWO 36 mm Round @ 7nm wavelength)

 - Sii (ZWO 36 mm Round @ 7nm wavelength)

 - Oiii (ZWO 36 mm Round @ 7nm wavelength)

Mount: 

- Losmandy GM811

- RAEXT EXTENSION DOVETAIL

- Losmandy 12" Tripod Extension

- Losmandy SADDLE PLATE FOR G-11 MOUNT

- Losmandy LW Tripod

- Alt-AZ/Elevation Tensioning bolts and washers (Michael Herman's)

Guiding: 

- ZWO 120mm mini (red filter)

- William Optics 32mm f/3.75 UniGuide Guidescope

- PHD2 Software (2.6.9 Dev 5)

  - Multistar option

  - RA algorithm:  Predictive PEC

  - Dec algorithm: Resist Switch

- Used previous calibration

- Dither: Small, every 2 frames

  

Acquisition: 

- ASI Air Polar Alignment

- Mini PC Beelink T4 @ scope

- MS Windows Remote Desktop to mini PC

- Sequence Generator Pro 3.2.660

- Flats & FlatDarks using NINA Flat Wizard