M63 - Sunflower galaxy

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VPR
Posts: 8
Joined: Sat May 09, 2020 3:40 pm

M63 - Sunflower galaxy

Post by VPR » Sun Jun 28, 2020 8:21 pm

M63 – Sunflower galaxy.

This is my fist serious attempt at AP. I have tried different things here with the goal of working out some of the bugs in many areas. Wanted to share this image given our discussion of Internal vs External calibration. This is all Internal SC calibration.

Eq used: TEC140, G11, PHD2, SharpCap, ZWO 1600MC cooled, ZWO 1600MM cooled, Triad Ultra NB filter, PixInsight.

Location: Backyard in Irvine, CA – Bortle 8; SQM of around 17.5.

Acquisition: Data was gathered over 6 nights. The first 4 nights were OSC subs (using the MC) and LUM subs (using the MM). No filters were used here. Last 2 nights were again using the MC and MM but this time with the Triad Ultra NB filter screwed on. Note that each night, 10darks and 20flats were shot before imaging. The SharpCap created master Dark and master Flat, were then used to calibrate each Light sub (before output). These calibrated Light subs were shot in blocks of 50 and saved for subsequent processing using PixInsight exclusively.

I am no expert at using PI given that this is my first attempt. I still question color saturation and have processed many versions looking for the ‘ideal’ color (you know how that goes…..). Processing was done using a Ryzen9 3950 with 16cores.

Calibrated Light Sub acquisition as follows:

1600MC (no filters)
OSC = 31 x 50 subs = 1550 subs
Sub Exposure = 15sec
Total Exposure = 6.45hrs
Gain = 60
Temp = -15deg

1600MM (no filters)
Lum = 25 x 50 subs = 1250 subs
Sub Exposure = 15sec
Total Exposure = 5.2hrs
Gain = 101
Temp = -15deg

1600MC (with Triad Ultra)
NB Triad OSC = 10 x 50 subs = 500 subs
Sub Exposure = 30sec
Total Exposure = 4.1hrs
Gain = 240
Temp = -15deg

1600MM (with Triad Ultra)
NB Triad Lum = 10 x 50 subs = 500 subs
Sub Exposure = 30sec
Total Exposure = 4.1hrs
Gain = 240
Temp = -15deg

Based on the short exposer time, very few subs had to be thrown out. I am estimating around 98% of the subs acquired are in the image below. This is a low quality JPEG (have not posted at any other site yet).
Attachments
M63 - 0.50.jpg
M63 - 0.50.jpg (212.94 KiB) Viewed 77 times

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oopfan
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Joined: Sat Jul 08, 2017 2:37 pm
Location: New York
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Re: M63 - Sunflower galaxy

Post by oopfan » Sun Jun 28, 2020 8:28 pm

Very nice detail. Great guiding!

EDIT: Now I see why the great guiding: short exposures.

Brian

VPR
Posts: 8
Joined: Sat May 09, 2020 3:40 pm

Re: M63 - Sunflower galaxy

Post by VPR » Sun Jun 28, 2020 9:31 pm

Brian ……. PHD2 total RMS was 0.49 to 0.77arcsec for the duration. Second factor is short exposure. The third factor is that I deployed differential stretch (small stars as opposed to using Star Reduction script). So, I think all three attributed to this. …… V.P

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