Abell 426 - 15.2 hrs integration time

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Dunmunro
Posts: 326
Joined: 10 Jan 2019, 01:11

Abell 426 - 15.2 hrs integration time

Post by Dunmunro » 01 Jan 2026, 20:21

I did this image on December 16/17 2025 using my 10in F5 SCT (F6.3 native reduced to F5 via a Starizona LF SCT reducer) on an CEM60 mount. I used an OAG guided ASI071 camera using 91 x 10min subs for a total integration time of 910 minutes or approximately 15.2 hours. I used an ASI small OAG and a Meade LPI Advanced GM camera (Sony mono 178 CMOS sensor) for autoguiding in 2x2 bin mode and 2x2 software binning. This OAG setup will find useable guidestars in ANY random field - it has never failed yet!

All aspects of image acquisition, centring, FF autoguiding and FF autofocusing were done with Astroart9 SP2. The target field was acquired robotically starting with the mount in the parked position. Using a script AA9 slewed to the approximate image centre, then took a 5 second exposure, and auto-platesolved the image, than automatically centred the OTA and camera on the target centre. AA9 then commanded the autoguider to acquire stars, autocalibrate, and then begin guiding. AA9 then did an initial FF autofocus and repeated the autofocus after each 600sec sub exposure; this held accurate focus over the entire ~16 hours of imaging.

Processing history
12:41:32 White balance 4 -1 -1 -1 2 -1 -1 -1
12:40:28 Flip vertical
12:34:54 Multiscale Lowpass 40 30 0 80
12:30:22 DDP 95 20 0 30 50 0 0
12:29:31 Histogram stretch 65535 11894 129046 -5 0
12:29:05 Deconvolution Richardson Lucy 20 2 100 25
( Sigma-sum stacking plus flats and darks)

Dunmunro
Posts: 326
Joined: 10 Jan 2019, 01:11

Re: Abell 426 - 15.2 hrs integration time

Post by Dunmunro » 02 Jan 2026, 15:40

Here I reprocessed 149 x 5min subs (12.4 hrs) of Abell 426 taken through my 10in F8 (F10 reduced to F8 using a Starizona LF SCT reducer) SCT on a CEM120 mount and an ASI071 OSC camera.

processing history:
08:18:46 Remove gradient adaptive sub. 95
01:21:48 Flip vertical
01:21:33 Rotate 90
01:21:08 White balance 4 -1 -1 -1 2 -1 -1 -1
01:20:51 DDP 95 20 0 30 50 0 0
01:20:33 Histogram stretch 65535 167873 1253951 -3 0
01:20:04 Deconvolution Richardson Lucy 25 2 95 20

I've improved my flat fielding techniques since, and here I had to use a weak gradient filter in lieu of better flats.

This image shows the effect of a longer focal length using the same OSC camera (unfortunately with a different camera orientation):

Dunmunro
Posts: 326
Joined: 10 Jan 2019, 01:11

Re: Abell 426 - 15.2 hrs integration time

Post by Dunmunro » 02 Jan 2026, 17:59

Dunmunro wrote:
02 Jan 2026, 15:40
Here I reprocessed 149 x 5min subs (12.4 hrs) of Abell 426 taken through my 10in F8 (F10 reduced to F8 using a Starizona LF SCT reducer) SCT on a CEM120 mount and an ASI071 OSC camera.

processing history:
08:18:46 Remove gradient adaptive sub. 95
01:21:48 Flip vertical
01:21:33 Rotate 90
01:21:08 White balance 4 -1 -1 -1 2 -1 -1 -1
01:20:51 DDP 95 20 0 30 50 0 0
01:20:33 Histogram stretch 65535 167873 1253951 -3 0
01:20:04 Deconvolution Richardson Lucy 25 2 95 20

I've improved my flat fielding techniques since, and here I had to use a weak gradient filter in lieu of better flats.

This image shows the effect of a longer focal length using the same OSC camera (unfortunately with a different camera orientation):
Abell426NGC1275C60D2024B.jpg
This image is processed as above but with the addition of a multiscale low pass filter to reduce noise:

10:50:59 Multiscale Lowpass 50 50 51 90

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