Hemisphere:  Northern  ·  Constellation: Cassiopeia (Cas)  ·  Contains:  IC 1805  ·  Sh2-190
Getting plate-solving status, please wait...
Melotte 15 / IC 1805 - The Heart of The Heart Nebula, 



    
        

            Steve Ludwig
Powered byPixInsight

Melotte 15 / IC 1805 - The Heart of The Heart Nebula

Getting plate-solving status, please wait...
Melotte 15 / IC 1805 - The Heart of The Heart Nebula, 



    
        

            Steve Ludwig
Powered byPixInsight

Melotte 15 / IC 1805 - The Heart of The Heart Nebula

Acquisition details

Dates:
Nov. 6, 2020
Frames:
41×300(3h 25′)
Integration:
3h 25′
Avg. Moon age:
20.13 days
Avg. Moon phase:
70.83%

RA center: 02h35m01s.80

DEC center: +61°2301.2

Pixel scale: 1.596 arcsec/pixel

Orientation: -145.672 degrees

Field radius: 0.555 degrees

More info:Open 

Resolution: 2088x1375

File size: 1.7 MB

Data source: Backyard

Description

I recently imaged the center of the heart nebula when I was waiting for M42 to reach a sufficiently high altitude. That's why I only got a little more than three hours of integration time. Considering that my scope is not the fastest and that I used an unmodified DSLR without filters, the result is not too bad, I think. Please let me know what you think about it.

Equipment

- Main scope: Bresser Messier 10" Newton (254/1270)

- Main camera: Nikon D3300 (unmodified)

- Guide scope: Orion AC 50/162 Deluxe Mini

- Guide camera: ZWO ASI 290MC

- Mount: Skywatcher EQ6-R

- Explore Scientific HR coma corrector

Acquisition

- 41 lights x 300 s = 3 h 25 min

- no dark, flat, bias frames

- no filters

- ISO 800

- Bortle 4

Processing

- stacked in DSS

-> bilinear debayer method & median kappa sigma clipping

- unmodified TIF opened in PixInsight

-> STF stretch

-> crop

-> dynamic background extraction

-> background neutralization

-> color calibration

-> histogram transformation

-> SCNR green to remove greenish noise

-> use of starnet++ module to separate stars and background

Stars

-> curves transformation to increase saturation of stars

Background

-> red channel extraction

-> range selection to create a smooth mask from the red channel image that contains the reddish hydrogen alpha regions

-> application of this mask to the original (color) background image

-> masked curves transformation to increase saturation of red hydrogen alpha regions without increasing color noise of the background

-> masked local histogram transformation to increase contrast of hydrogen alpha regions

-> pixel math to recombine stars and background

-> TGV denoise to reduce noise

-> resample 50%

-> ACDNR with integrated lightness mask to reduce noise further

-> histogram transformation

-> rotation to ensure that star diffraction spikes are vertical/horizontal

-> dynamic crop

-> background neutralization to remove an overall reddish tint of the image

-> saved as jpg

Comments

Revisions

  • Melotte 15 / IC 1805 - The Heart of The Heart Nebula, 



    
        

            Steve Ludwig
    Original
  • Melotte 15 / IC 1805 - The Heart of The Heart Nebula, 



    
        

            Steve Ludwig
    B
  • Melotte 15 / IC 1805 - The Heart of The Heart Nebula, 



    
        

            Steve Ludwig
    C
  • Final
    Melotte 15 / IC 1805 - The Heart of The Heart Nebula, 



    
        

            Steve Ludwig
    D

B

Description: Added another background neutralization as final processing step. Let me know which revision you like more. Looking at my widefield image of the heart nebula, I tend to think that the original version might look a bit more natural.

Uploaded: ...

C

Description: For the latest revision I applied an additional run of "TGV Denoise" on the background and did some curves/histogram fine-tuning to bring out the nebulosity more.

Uploaded: ...

D

Description: In revision D, I applied a further instance of ACDNR to reduce the noise of the background. This in turn allowed me to increase the background brightness a bit.

Uploaded: ...

Sky plot

Sky plot

Histogram

Melotte 15 / IC 1805 - The Heart of The Heart Nebula, 



    
        

            Steve Ludwig

In these public groups

PixInsight Addicts