Hemisphere:  Northern  ·  Constellation: Cassiopeia (Cas)  ·  Contains:  IC 1805  ·  IC 1831  ·  IC 1848  ·  Part of the constellation Perseus (Per)  ·  The star 11Per  ·  The star 4Per  ·  The star 53Cas  ·  The star 8Per  ·  The star 9Per  ·  The star γPer  ·  The star εCas  ·  The star ηPer  ·  The star ιCas  ·  The star τPer
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Heart & Soul Nebulas (IC 1805 and 1848) and the Perseus Double Cluster (NGC 869 and 884), 



    
        

            Doug Gray
Heart & Soul Nebulas (IC 1805 and 1848) and the Perseus Double Cluster (NGC 869 and 884)
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Heart & Soul Nebulas (IC 1805 and 1848) and the Perseus Double Cluster (NGC 869 and 884)

Getting plate-solving status, please wait...
Heart & Soul Nebulas (IC 1805 and 1848) and the Perseus Double Cluster (NGC 869 and 884), 



    
        

            Doug Gray
Heart & Soul Nebulas (IC 1805 and 1848) and the Perseus Double Cluster (NGC 869 and 884)
Powered byPixInsight

Heart & Soul Nebulas (IC 1805 and 1848) and the Perseus Double Cluster (NGC 869 and 884)

Technical card

Imaging telescopes or lenses: Nikon 35mm f1.8

Imaging cameras: ZWO ASI294MM-Pro

Mounts: iOptron CEM70  ·  iOptron Tri-Pier

Guiding telescopes or lenses: ZWO 30mm f/4 Mini Guide Scope

Guiding cameras: ZWO 290MC

Software: PHD2 Guiding

Filters: Antlia SII 3.5nm 36mm  ·  Antlia OIII 3.5nm 36mm  ·  Antlia Ha 3.5nm 36mm

Accessory: ZWO ASIAir Pro  ·  ZWO EFW 7x36mm


Dates:Dec. 19, 2020Dec. 20, 2020Dec. 21, 2020

Frames:
Antlia Ha 3.5nm 36mm: 40x300" (gain: 120.00) -10C bin 2x2
Antlia OIII 3.5nm 36mm: 45x300" (gain: 120.00) -10C bin 2x2
Antlia SII 3.5nm 36mm: 26x300" (gain: 120.00) -10C bin 2x2

Integration: 9.2 hours

Darks: ~30

Flats: ~30

Bias: ~60

Avg. Moon age: 6.00 days

Avg. Moon phase: 35.68%


Basic astrometry details

Astrometry.net job: 4117280

RA center: 2h 37' 27"

DEC center: +59° 22' 26"

Pixel scale: 26.802 arcsec/pixel

Orientation: 268.164 degrees

Field radius: 11.014 degrees


Resolution: 2450x1659

Locations: Backyard, Redwood City, CA, United States

Data source: Backyard

Description

Heart Nebula, Soul Nebula, Fishhead Nebula, and the Perseus Double Cluster, all in one narrowband shot with room to spare.

Long list of learnings on this project. After seeing the coma in my previous 35mm shots with the aperture wide open, I managed to create a 4mm plastic spacer out of a zip-tie to keep the speed set to around f/2-and-a-half-ish. That, and some cropping, seems to have done the trick.

Prior to this project I had only taken flats in the Luminance channel and could not figure out why I had these strange glowing patterns in very long exposures in the Ha channel. These Antlia filters are not parafocal (Ha & SII are close), so I should have guessed this would be a big deal. Getting those flats right makes much more of the image usable (although I still cropped quite a bit in this case).

The other thing that I learned on this project was the wisdom of editing each color channel separately in monochrome before combining. It takes more time for sure, but I can't see as much detail in the red and blue channels otherwise. This really helps when trying to remove the gradients.

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Heart & Soul Nebulas (IC 1805 and 1848) and the Perseus Double Cluster (NGC 869 and 884), 



    
        

            Doug Gray