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Contains:  IC 3476, M 88, NGC 4501, NGC 4477, NGC 4474, NGC 4473, NGC 4461, NGC 4459, NGC 4438, The Eyes, NGC 4435, NGC 4425, NGC 4413, M 86, NGC 4406, NGC 4402, NGC 4388, M 84, NGC 4374
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Makarian's Chain and M88, 





    
        

            Andrew Klinger
Makarian's Chain and M88

Makarian's Chain and M88

Technical card

Resolution: 3389x2502

Dates:April 10, 2018

Frames:
ZWO B 1.25": 50x180" (gain: 76.00) -20C bin 1x1
ZWO G 1.25": 40x180" (gain: 76.00) -20C bin 1x1
ZWO L 1.25": 167x180" (gain: 76.00) -20C bin 1x1
ZWO R 1.25": 43x180" (gain: 76.00) -20C bin 1x1

Integration: 15.0 hours

Darks: ~64

Flats: ~30

Bias: ~200

Avg. Moon age: 24.10 days

Avg. Moon phase: 29.81%

Bortle Dark-Sky Scale: 3.00

Astrometry.net job: 2070179

RA center: 187.136 degrees

DEC center: 13.499 degrees

Pixel scale: 2.527 arcsec/pixel

Orientation: 191.794 degrees

Field radius: 1.479 degrees

Locations: Atoka dark site, Atoka, Oklahoma, United States

Data source: Unknown

Description

I'm ending this year's galaxy season with the ultimate existential crisis!
Seen here as the fish hook shape is what is known as "Makarian's Chain", a group of galaxies with an average distance of 50 million light years from Earth. These galaxies are all a part of the Virgo Supercluster, which the Local Group (containing our own Milky Way galaxy) is all a part of. But those aren't the only galaxies in this image. Every fuzzball in this picture that doesn't look like a star is a galaxy, each with 100-400 billion stars, and statistically speaking, many of those stars will have a solar system. As a little bonus, I framed the beautiful spiral galaxy M88 in the lower right corner.

Equipment:
OTA: William Optics GT81 w/0.8x reducer (382mm fl at f/4.7)
Mount: Orion Sirius EQ-G (HEQ-5)
Guidescope: Orion 50mm guidescope
Guiding camera: Orion StarShoot Autoguider
Imaging camera: ZWO ASI1600MM-Cool

Software:
SGP
PHD2
CdC
PixInsight

Acquisition:
Location: Atoka, Oklahoma (Bortle 3), and Fort Griffin State Historic Park, Texas (Bortle 3)
Dates: 4/10/2018, 4/14/2018, 4/15/2018, 5/5/2018
Gain: 76 Offset: 15
Camera temp: -20C
L: 167x180"
R: 43x180"
G: 40x180"
B: 50x180"
Total integration time: 15hrs
64x darks per calibration
30x flats per calibration
200x bias (master bias in library)

Preprocessing:
Batch PreProcessing script to generate calibrated images
StarAlignment to register all frames to a reference L
LocalNormalization on RGB frames
ImageIntegration
DrizzleIntegration
DynamicCrop each master
DBE on each master
LinearFit G and R to B

RGB processing:
PhotometricColorCalibration
SCNR green 50%
ArcsinhStretch for a small stretch
HistogramTransformation x2 to finish the stretch
SCNR green 100%
ExponentialTransformation w/ mask to push the galaxies slightly brighter
CurvesTransformation for saturation
ColorSaturation to target blue saturation

L processing:
Deconvolution
HistogramTransformation x2 to stretch image
Duplicated the image to create a starless version, using a starmask and several iterations of MMT and MT. Then pushed the faint nebulosity in the starless version using PixelMath expression: "1-(1-$T)*(1-$T)"
Combined the starless version with the image using PixelMath expression "F=0.4; (1-(1-$T)*(1-s)*F)+($T*~F)" followed by the same expression with F=0.2 (s=starless photo).
HistogramTransformation to move blacks in
LocalHistogramEqualization to improve contrast within galaxies
MultiscaleLinearTransform for slight sharpening

Combined L and RGB with LRGBCombination tool
CurvesTransformation to neutralize background color
ACDNR for slight noise reduction
HistogramTransformation to move black point in
Resampled to 40% for web posting

Comments

Author

ak_astro
Andrew Klinger
License: None (All rights reserved)
3111
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Makarian's Chain and M88, 





    
        

            Andrew Klinger