NGC 4490 is a galaxy colliding with the smaller NGC 4485 galaxy, and both are about 25 million light years away. This image was taken with a monochrome camera through filters for luminance (all visible light), red, green, blue, and Hydrogen-alpha (656nm), which were combined into a color image. The Hydrogen-alpha was combined with red (described below) to make the HaLRGB image. The pink Ha regions are star forming nebulae within the galaxies. This got cropped out of the final pic, but I ended getting some gorgeous diffraction spikes on this star near the edge of the full FOV

Places where I host my other images:

Flickr | Instagram

Equipment:

• TPO 6" F/4 Imaging Newtonian

• Orion Sirius EQ-G

• ZWO ASI1600MM-Pro

• Skywatcher Quattro Coma Corrector

• ZWO EFW 8x1.25"/31mm

• Astronomik LRGB+CLS Filters- 31mm

• Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm

• Agena 50mm Deluxe Straight-Through Guide Scope

• ZWO ASI-120MC for guiding

• Moonlite Autofocuser

Acquisition: 27 hours 37 minutes (Camera at half Unity Gain, -15°C)

• Ha - 128x360"

• Lum - 464x60"

• Red - 152x60"

• Green - 150x60"

• Blue - 123x60"

• Flats- 30 per filter

• 24 JimmyFlats per broadband filter

Capture Software:

• Captured using N.I.N.A.

PixInsight Processing:

• BatchPreProcessing (with premade JimmyFlats)

• StarAlignment

• Blink

• ImageIntegration

• DrizzleIntegration (2x, Var β=1.5)

• DynamicCrop

• DynamicBackgroundExtraction

duplicated each image and removed stars via StarXterminator. Ran DBE to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)

$T * med(model) / model

Luminance:

• BlurXTerminator

• ArcsinhStretch + histogramtransformation to bring nonlinear

RGB:

• ChannelCombinaiton to combine monochrome R, G, B stacks into color image

• SpectroPhotometricColorCalibration

• BlurXTerminator (correct only mode)

• HSV Repair

making clean Ha

loosely following this guide

This basically subtracts any broadband signal from the Ha pic, leaving only the Ha emission, which is then combined in with the red and a little bit of the blue channels

• PixelMath to isolate just Ha

Ha-Q * (Red-med (Red)), Q=0.75

• PixelMath to add Ha into RGB image

Red = $T+B*(Ha_Clean - med(Ha_Clean))

Green = $T

Blue = $T+B0.2(Ha_Clean - med(Ha_Clean))

B variable = 0.6 (this controls how strongly the Ha is added)

Nonlinear

• ArcsinhStretch + histogramtransformation to bring HaRGB image nonlinear

• MLT for large scale chrominance noise reduction

• shitloads of curve transformations to adjust lightness, contrast, saturation, etc (with various luminance and star masks)

• slight SCNR to remove some greens

• LRGBCombination with stretched Luminance

• DeepSNR

• more curves

• ColorSaturation to slightly desaturate the Ha regions (they were very pink compared to the rest of the galaxy

• slight noisexterminator

• LocalHistogramEqualization

• even more curves

• Resample to 75%

• DynamicCrop onto just the galaxy

• annotation

Iirc the original goal was ‘at least 10’ but maybe up to 100 flights for a booster. No way to really know without flying them a lot

It may not be as big or well known as the other well known cluster in Hercules (M13), but it sure looks nice. Captured over 4 nights in July/August 2024 from a Bortle 9 zone

Places where I host my other images:

Instagram | Flickr

Equipment:

• TPO 6" F/4 Imaging Newtonian

• Orion Sirius EQ-G

• ZWO ASI1600MM-Pro

• Skywatcher Quattro Coma Corrector

• ZWO EFW 8x1.25"/31mm

• Astronomik LRGB+CLS Filters- 31mm

• Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm

• Agena 50mm Deluxe Straight-Through Guide Scope

• ZWO ASI-120MC for guiding

• Moonlite Autofocuser

Acquisition: 6 hours 55 minutes (Camera at half Unity Gain, -15°C)

• Lum - 209x60"

• Red - 78x60"

• Green - 62x60"

• Blue - 66x60"

• Flats- 30 per filter

• 24 JimmyFlats per filter

Capture Software:

• Captured using N.I.N.A.

PixInsight Processing:

• BatchPreProcessing (with premade JimmyFlats)

• StarAlignment

• Blink

• ImageIntegration

• DrizzleIntegration (2x, Var β=1.5)

• DynamicCrop

• DynamicBackgroundExtraction

duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)

$T * med(model) / model

Luminance:

• BlurXTerminator (correct only mode)

• ArcsinhStretch + histogramtransformation to bring nonlinear

RGB:

• ChannelCombinaiton to combine monochrome R, G, B stacks into color image

• BlurXTerminator (correct only mode)

• SpectroPhotometricColorCalibration

• HSV Repair

• ArcsinhStretch + histogramtransformation to bring nonlinear

• Curves to saturate it a little

• MLT for large scale chrominance noise reduction

Nonlinear:

• LRGBCombination with stretched L as luminance

• DeepSNR Noise reduction

• Several CurveTransformations to adjust lightness, contrast, colors, saturation, etc.

• Invert > SCNR > invert > SCNR to remove some greens and magentas

• More curves

• A little bit of noiseXterminator

• DynamicCrop in on the clustert

• Resample to 75%

• Annotation

Oh no! Where will I go to see OF spam bots now???

Only 7 years ago!

https://www.youtube.com/watch?v=qU7FuAswPW0

I love procrastinating on processing my images! I got set up early at a dark site last month and decided to shoot the sun while it was still up. There were a shitload of sunspots, including AR3697 in the bottom right. This sunspot group was the one that gave us the wonderful aurora back in May (back when it was known as AR3664)

Places where I host my other images:

Flickr | Instagram

Equipment:

• TPO 6" F/4 Imaging Newtonian

• Orion Sirius EQ-G

• ZWO ASI1600MM-Pro

• Skywatcher Quattro Coma Corrector

• ZWO EFW 8x1.25"/31mm

• Astronomik LRGB+CLS Filters- 31mm

• Moonlite Autofocuser

• Astrozap BAADER AstroSolar Density 5 filter

Acquisition:

• Green filter - 5000 frames at gain 139 and 0.324ms exposure

Capture Software:

• Captured using sharpcap

Processing:

• Stacked the best 25% of frames in Autostakkert, 2X resample and autosharpened

• Colorized using curves in Photoshop

• More lightness/Hue Adjustments

• Astrosurface wavelets to remove some grid artifacts from stacking

• STF applied in pixinsight

• Annotatation

I’m guessing it’s called that because it’s kinda headphone shaped. It was discovered in the 30’s so I’m assuming only the brightest parts of the nebula were visible to the astronomers.

This image is a combination of false color narrowband images for the nebula itself, plus true color RGB stars (the nebula is mostly red and a little blue in true color). If you zoom in to the center you can see the very blue white dwarf that caused the planetary nebula to form. Also for those curious this is what a single 10 minute long Ha exposure looks like (image total is 83.5 hours exposure). Captured over 33 nights from Jan-May 2024 from a bortle 9 zone.

Places where I host my other images:

Flickr | Instagram

Equipment:

• TPO 6" F/4 Imaging Newtonian

• Orion Sirius EQ-G

• ZWO ASI1600MM-Pro

• Skywatcher Quattro Coma Corrector

• ZWO EFW 8x1.25"/31mm

• Astronomik LRGB+CLS Filters- 31mm

• Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm

• Agena 50mm Deluxe Straight-Through Guide Scope

• ZWO ASI-290mc for guiding

• Moonlite Autofocuser

Acquisition: 83 hours 30 minutes (Camera at -15°C), NB exposures at unity gain and BB at half unity

• Ha - 238x600"

• Oiii - 247x600"

• R - 54x60"

• G - 53x60"

• B - 54x60"

• Darks- 30

• Flats- 30 per filter

Capture Software:

• Captured using N.I.N.A. and PHD2 for guiding and dithering.

PixInsight Preprocessing:

• BatchPreProcessing

• StarAlignment

• Blink

• ImageIntegration per channel

• DrizzleIntegration (2x, Var β=1.5)

• Dynamic Crop

• DynamicBackgroundExtraction 3x

duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)

$T * med(model) / model

Narrowband Linear:

• Blur and NoiseXTerminator

• StarXterminator to completely remove stars (to be later replaced by the RGB ones)

• ArcsinhStretch to slightly stretch nonlinear

• iHDR 2.0 script (low preset) to stretch each channel the rest of the way.

here’s the link to the repo if you want to add it to your own PI install.

RGB Linear:

• ChannelCombination to combine monochrome R G and B frame into color image

• SpectroPhotometricColorCalibration

• BlurXTerminator for star sharpening (correct only)

• HSV Repair

• StarXterminator to generate a stars-only image

• ArcsinhStretch + HT to stretch nonlinear (to be combined with starless narrowband image later)

• Invert > SCNR > invert to remove magentas

• Curves to saturate the stars a bit more

Nonlinear:

• PixelMath to combine stretched Ha and Oiii images into color image (/u/dreamsplease’s palette)

R = iif(Ha > .15, Ha, (Ha*.8)+(Oiii*.2))

G = iif(Ha > 0.5, 1-(1-Oiii)*(1-(Ha-0.5)), Oiii *(Ha+0.5))

B = iif(Oiii > .1, Oiii, (Ha*.3)+(Oiii*.2))

• NoiseX again

• Background Neutralization

• Shitloads of Curve Transformations to adjust lightness, hues, contrast, saturation, etc

• even more curves

• Pixelmath to add in the stretched RGB stars only image from earlier

This basically re-linearizes the two images, adds them together, and then stretches them back to before. More info on it here)

mtf(.005,

mtf(.995,Stars)+

mtf(.995,Starless))

• Couple final curves

• Resample to 65%

• DynamicCrop

• Annotation

Sh2-64 is the red nebula to the right of the image. It frames up pretty well with the more golden stars seen in the milky way core. I probably should’ve gotten more exposure time to help bring out some of the dark nebula details, but it was only clear for one night at the dark site (at least the night went perfectly, which is rare for trips out to the middle of nowhere). Captured on June 7th, 2024 from a Bortle 3 zone (Deerlick Astronomy Village)

Places where I host my other images:

Flickr | Instagram

Equipment:

• TPO 6" F/4 Imaging Newtonian

• Orion Sirius EQ-G

• ZWO ASI1600MM-Pro

• Skywatcher Quattro Coma Corrector

• ZWO EFW 8x1.25"/31mm

• Astronomik LRGB+CLS Filters- 31mm

• Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm

• Agena 50mm Deluxe Straight-Through Guide Scope

• ZWO ASI-290mc for guiding

• Moonlite Autofocuser

Acquisition: 5 hours 44 minutes (Camera at half unity gain -15°C)

• L - 76x120"

• R - 32x120"

• G - 32x120"

• B - 32x120"

• Darks- 30

• Flats- 30 per filter

Capture Software:

• Captured using N.I.N.A. and PHD2 for guiding and dithering.

PixInsight Preprocessing:

• BatchPreProcessing

• StarAlignment

• Blink

• ImageIntegration per channel per panel

• DrizzleIntegration (2x, Var β=1.5)

• Dynamic Crop

• DynamicBackgroundExtraction

Luminance Linear:

• BlurXterminator (Correct only)

• NoiseXterminator

• HistogramTransformation + sketchpad’s iHDR script (low preset) to stretch to nonlinear

RGB Linear:

• ChannelCombination to combine monochrom R G and B stacks into color image

• SpectrophotometricColorCalibration

• BlurXterminator (correct only)

• HSV repair

• ArcsinhStretch + iHDR script (low preset) to stretch to nonlinear

Nonlinear Processing:

• LRGBCombination using stretched L as luminance

• DeepSNR

• Various curve adjustments for lightness, contrast, hue, saturation, etc (with varying lum/star masks)

• Slight SCNR green

• ColorSaturation to boost the saturation of the Ha region

• More curves

• NoiseXterminator

• invert > SCNR > invert to remove some magentas

• LocalHistogramEqualization

two rounds at scale 16 and 132 to target different sized structures

• LOTS more curve adjustments

• MultiscaleLinearTransform for chrominance noise reduction

• Even more curves

• Resample to 60%

• Annotation