Celestial hemisphere:  Northern  ·  Constellation: Auriga (Aur)  ·  Contains:  IC 410  ·  LBN 807  ·  LDN 1530  ·  NGC 1893  ·  Sh2-236
Tadpoles (SHO) (Collaboration), Linda
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Tadpoles (SHO) (Collaboration), Linda
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Acquisition details



This was a collaborative effort across four people (myself, @gmadkat, @Chris Kagy@jmarinotero), four telescopes and three timezones. I was lucky enough to have access to two great systems (@gmadkat is a teammate on one) though neither is owned by me and a friends and fellow NOVAC club members in Arlington, Virginia and Washington, DC contributed data from their systems.  

Here are the links to the other collaborator's versions:
Juan's version: https://www.astrobin.com/e6b71u/
Chris's version: https://www.astrobin.com/wkq7xi/
Gowri's version: https://www.astrobin.com/qlwd88

Here are the rigs:
Location    Telescope                        Filters       Camera                Mount                                       Image Scale
California  Planewave CDK14          Astrodon  FLI PL16803        Astro-Physics 1600 GTO         0.73
Texas         Ceravolo 300                   Astrodon  FLI ML16200       Astro-Physics 1100 GTO AE   0.83
Virginia     Astrotech AT80EDT         Astrodon  ASI183mm Pro   Ioptron GEM45                       1.03
DC             Sky-Watcher Esprit 100  Astrodon  ASI1600mm Pro Software Bisque MyT             1.43

One of the Planewave subs was used as the registration reference and everything was registered to that. 

Now, from a detail point of view, adding in the Virginia and DC data doesn't really help and arguably hurts a bit but it was a fun experiment to see if we could make it work. I had to fight with StarAlignment but finally got it to register most of the subs. The end result was pretty nice! Thankfully the Tadpoles (IC 410) is fairly bright in all three filters and when all the data was integrated this produced one of the easiest OIII and SII masters to work with I've used. 

Here's how the time (in minutes)  broke down for the registered subs:
Location    H-a     OIII     SII      Total
California  510     585     660     1755
Texas         310     500     480     1290    
Virginia      470     425     485     1380
DC               600    895         0     1495
Total         1890   2405  1625     5920

The total integration time was 98 hours 40 minutes.

The California rig used 900s subs, Texas used 600s and the others used 300s.

The Tadpoles is one of those nebulae that just grab your eye. It's such an organic looking nebula. It's so distinctive looking that you instantly know what you are looking at. 

Here was my processing workflow:
I used a California sub to register all the datasets since that had the finest image scale.  Integration was normal. I considered using the NSG script but it was not happy with some of the subs probably due to when they had been calibrated (data came from over a period of months) but since I couldn't run NSG I just ran integration with PSF Weights. 

each S H and O:
dynamic crop

on copies of each S, H and O
histogram transformation
TGV Denoise

on copy of starless H alone being used for lum:
LHE (2 scales)
dark structure enhance
histogram transformation for contrast
MLT (sharpening)

channel combination original S, H and O
histogram transformation to get stars to desired level
duplicate stars and run starnet2 to generate star_mask

channel combination (SHO)
channel combination in lum
curves (color)
pixel math in stars using star_mask
a touch more TGV denoise luminance noise reduction
color mask script for yellow
slight curves boost to enhance yellow areas



  • Tadpoles (SHO) (Collaboration), Linda
  • Final
    Tadpoles (SHO) (Collaboration), Linda


Description: fixed some clipping around the "heads" of the tadpoles.

Uploaded: ...

Sky plot

Sky plot


Tadpoles (SHO) (Collaboration), Linda