Capturing a Cosmic Ghost: The Garlic Nebula (Abell 85 / CTB 1)

 

The Story Behind the Image

Hidden in the northern constellation Cassiopeia lies the expanding shockwave of a star that tore itself apart roughly 10,000 years ago. Officially cataloged as CTB 1 and Abell 85, astrophotographers affectionately call it the Garlic Nebula (or the Medulla Nebula) because its delicate, braided filaments of glowing gas look remarkably like a bulb of garlic suspended in space.

When astronomer George Abell first spotted this faint bubble on photographic plates in 1955, he assumed it was a planetary nebula—the gentle shedding of a Sun-like star. Radio astronomers later realized they were looking at something far more violent: a massive supernova remnant spanning roughly 100 light-years across, sitting over 10,000 light-years away from Earth. Even more fascinating, the stellar core left behind by that explosion—a hyper-velocity pulsar named PSR J0002+6216—was blasted out of the shell at over 1,000 kilometers per second (2.2 million miles per hour), leaving a faint trail behind it like a cosmic cannonball.

Why It’s Such a Tough Target

To the human eye—even through a massive backyard telescope—the Garlic Nebula is completely invisible. Its surface brightness is extraordinarily low, and imaging it from a light-polluted backyard means fighting an uphill battle against city skyglow.

To cut through the light pollution, this image was captured using narrowband filters—specialized pieces of optical glass that block out nearly all streetlamp and moonlight glare while isolating the exact wavelengths of light emitted by energized Hydrogen (Ha) and Oxygen (OIII) gas. In a single 4-minute camera exposure, the nebula barely registers as a smudge; it takes hours of stacking dozens of individual frames together to coax those delicate inner filaments and the faint blue outer Oxygen shell out of the background noise.

Technical & Acquisition Notes (For the Astro Nerds)

Because CTB 1 is notoriously faint at f/5.6, the focus of this project was maximizing signal-to-noise ratio (SNR) and refining guiding efficiency across multi-night sessions.

• Target: Abell 85 / CTB 1 (The Garlic Nebula)

• Location: Backyard Observatory (Bortle 6–7)

• Telescope: Astro-Tech AT102ED w/ 0.8x Reducer/Flattener (571mm focal length @ f/5.6)

• Camera: QHY163M Monochrome CMOS (cooled to -15°C)

• Mount & Guiding: Celestron CGEM, guided via PHD2

• Filters & Integration:

  • Hydrogen-alpha (Ha): 150 × 240s

  • Oxygen-III (OIII): 74 × 240s

  • Total Integration Time: about 15 hours

Capture & Processing Workflow

• Acquisition & Automation: Captured using N.I.N.A. with automated focusing via ZWO EAF. To keep sub-frame overhead low without sacrificing fixed-pattern noise rejection, dithering was configured to trigger every 2 frames with a 1.0-pixel settle tolerance and a 5-second minimum settle time—allowing the CGEM to damp out cleanly in under 10 seconds per dither. Plate-solving was handled through the Green filter for fast, reliable star detection before swapping into narrowband sequences.

• Calibration & Stacking: Calibrated with matched darks and flats, then registered and stacked separately as master Ha and OIII files in DeepSkyStacker using Kappa-Sigma Clipping (handling multi-session gain sets via File Groups).

• Post-Processing: Background gradients and residual noise were cleaned up in GraXpert before moving to Photoshop for non-linear stretching and HOO palette mapping. StarNet++ was used to separate the stars from the nebulosity, allowing selective micro-contrast enhancements and curve adjustments on the faint outer blue OIII shell without bloating the starfield, before re-combining the stars using the Lighten blend mode.

Clear skies, and feel free to drop any questions about the nebula or the capture setup in the comments below!

Capturing the Fiery Pillars of NGC 7822

NGC 7822 

NGC 7822 has always been one of those targets that demands attention. Located in the constellation Cepheus, this giant emission nebula and star-forming complex is packed with chaotic dust pillars, glowing hydrogen gas, and powerful young stars carving out deep cavities in the molecular cloud.

After spending some quality imaging time under the backyard skies, I’m thrilled to wrap up this rendition and share a look at both the target itself and how this final image came together.

About the Target: NGC 7822

Spanning a massive patch of the sky, NGC 7822 is driven by energetic O-type stars—some of the hottest and brightest stars in our galaxy—whose stellar winds and radiation sculpt the iconic, pillar-like structures reminiscent of the famous Pillars of Creation in the Eagle Nebula.

Imaging this in pure narrowband Hydrogen-Alpha ($H\alpha$) allows you to strip away the overwhelming wash of starlight and focus entirely on the intricate, glowing architecture of the gas clouds and dark dust lanes.

Capture Details

• Telescope: AT102ED refractor paired with a 0.8x reducer/flattener

• Camera: QHY163M monochrome camera

• Filters: Narrowband Hydrogen-Alpha ($H\alpha$) and Oxygen 3 (Oiii)

• Location: Backyard observatory setup (battling local light pollution, but leaning heavily on narrowband filtering to punch through)

Because narrowband filters act like extreme gatekeepers—letting through only a razor-thin slice of the light spectrum while blocking out urban glow—the sub-exposures came in clean, framing the dense structural details of the nebula right from the start.

The Processing Workflow

Getting the most out of a narrowband dataset like this relies heavily on a disciplined post-processing pipeline. For this image, I leaned into a starless workflow to maximize dynamic range and contrast without compromising star sizes or highlights.

1. Star Extraction: Using StarNet++ early in the workflow on the linear stack, I separated the star field entirely from the nebulosity. This allowed me to stretch and process the gas clouds independently.

2. Stretching & Contrast: With the stars safely out of the way, I stretched the nebulosity to bring out the faint wisps and sharpened the micro-contrast around the central pillars, giving the complex a rich, 3D sense of depth.

3. Noise Control: To tame the high-frequency luminance noise in the deep background fields without destroying the delicate outer gas filaments, I applied a very subtle, unmasked touch of Camera Raw noise reduction. Keeping it unmasked and light smoothed the canvas gracefully without giving the nebula an artificial, over-processed look.

4. Recombination: Finally, the star layer was screened back onto the processed starless narrowband master, preserving tight, clean star profiles against a deep, velvety background.

Final Thoughts

Working on NGC 7822 is always a rewarding challenge, and this pure $H\alpha$ Oiii
rendition really highlights the dramatic, chaotic beauty of the region.

With this one officially in the books, it's time to turn my attention to setting up for some fresh $O\text{III}$ data on the Garlic Nebula (CTB 1) next. Clear skies, everyone!

Capturing the Roar of the Cosmos: Imaging Sh2-132 (The Lion Nebula) in HOO

 

Located in the constellation Cepheus, Sharpless 2-132 (Sh2-132)—commonly known as the Lion Nebula—is a vibrant, complex emission nebula sitting approximately 10,000 light-years away from Earth. Powered by massive, hot Wolf-Rayet and OB stars, this cosmic beast features massive interstellar dust clouds, sweeping arcs of ionized oxygen OIII, and dense pockets of glowing hydrogen gas H alpha.

While the bright central body of the nebula dominates the frame, revealing the full extent of its faint outer envelopes and subtle structures takes patience and dedicated integration time.

Acquisition & Target Info

• Target: Sh2-132 / The Lion Nebula

• Constellation: Cepheus

• Distance: ~10,000 light-years

• Total Integration Time: ~8 Hours  (4 hrs Ha, 4 hrs Oiii)

• Filter Configuration: Narrowband HOO H Alpha mapped to Red, OIII split across Green & Blue)

With 8 hours of narrowband data collected, the primary goal for this target was to capture a high signal-to-noise ratio in both the heavy H alpha filaments and the fainter, delicate $\text{OIII}$ loop sweeping through the lower region of the frame.

Processing Workflow & Lessons Learned

Processing Sh2-132 presented a great opportunity to refine a starless-assisted workflow in Adobe Photoshop. Here is how the final image came together:

1. Star Removal & Background Prep

• Extracted the starless base using StarNet to allow dedicated local processing on the nebulosity without bloating the starfield.

• Cleaned up minor pixel-level red artifacts and star remnants left behind by StarNet before working on contrast stretches.

2. Preserving Natural H\alpha Falloff

• The Challenge: High-contrast narrowband stretches can sometimes create harsh, abrupt boundaries where dense gas meets background space.

• The Solution: Rather than over-clipping the black point, careful curve adjustments were used on the starless base to preserve the smoky, continuous transition of outer H alpha wisps as they dissolve into deep space.

3. Star Integration & Taming Halos

• Stars were extracted from the narrowband stack and screen-blended back over the starless nebula layer.

• Applied localized mid-tone burn adjustments to tame brighter star halos along the outer edges, keeping the viewer's focus on the nebula's core details.

A New Final Rendition of a Distant Spiral Galaxy

 

NGC 7331, the Deer Lick Group

I’ve spent the past several nights slowly shaping this image, refining the stars, balancing the colors, and bringing out the faint outer halo of the galaxy. This final rendition is the version I’m happiest with — everything feels like it sits naturally in the same universe.

My main goal was to present the galaxy in a way that feels both natural and true to the data. I focused heavily on star color separation without over‑reducing them, lifting the halo using controlled mid‑low curves, and matching the background noise so the entire field blends smoothly. The core and dust lane were handled with care to avoid clipping or artificial sharpening, keeping the structure crisp but realistic.

The last tweak I made helped the halo settle more gently into the background, giving the galaxy a sense of depth and presence without introducing glow or artifacts. It’s a subtle change, but it made a noticeable difference in how the whole image feels.

This is the version I’m calling final — a balanced, cohesive presentation of the data and a satisfying end to this particular processing journey.

Equipment • SkyWatcher AL55i Pro mount • Astro-Tech AT102ED refractor • Astro-Tech 0.85× reducer/flattener • QHY163M monochrome camera • RGB

Acquisition • Captured with N.I.N.A • No luminance channel • Calibrated with 25 flats per color and 25 darks

Processing • Star color separation and controlled saturation • Halo lift using mid‑low curves • Background noise matched for natural blending • Core preserved without clipping • Final refinement in Photoshop

Thanks for following along with my astrophotography journey — more images coming soon.

Another Cosmic Flower, This One in Cygnus

 

I spent a few clear nights recently photographing one of my favorite deep‑sky objects: the Tulip Nebula (SH2-101), a beautiful cloud of glowing gas tucked away in the constellation Cygnus. It’s called the Tulip because of its curved, petal‑like shape — and once you see it, the name makes perfect sense.

This nebula is about 6,000 light‑years away, but with the right equipment and a little patience, you can capture its delicate structure from right here on Earth.

How I Captured It

For this image, I used a small refractor (AT102ED) telescope and a monochrome astronomy camera (QHY163M) paired with special filters that isolate two types of glowing gas:

• Hydrogen‑alpha (Ha): shows the bright red “petals”

• Oxygen‑III (OIII): reveals the softer blue wisps around the edges

These filters let me photograph the nebula even when the Moon is bright, because they cut through most of the skyglow.

I took many long exposures over several nights, then combined them into a single image. It’s a slow process, but that’s part of the fun — watching the nebula slowly emerge from the darkness.

A Little Processing Magic

To keep the image clean and balanced, I used a tool called StarNet, which separates the stars from the nebula. This lets me work on each part independently:

• The nebula gets careful stretching and contrast adjustments to bring out the fine details.

• The stars get their own gentle processing so they stay natural and not overpowering.

Once both look right, I blend them back together. It’s a simple step that makes a big difference in clarity.

The Final Result

The finished image shows the Tulip Nebula glowing softly in red and blue, surrounded by a dense field of stars. The hydrogen forms the bright central bloom, while the oxygen adds a cool halo around it. It’s one of those objects that feels both delicate and powerful — a cosmic flower floating in the Milky Way.

Astrophotography is a mix of science, patience, and a little artistic touch, and this nebula is a perfect example of how all three come together.

Eastern Veil Nebula – New Process, New Results

 

I finally had a chance to revisit the Eastern Veil Nebula with a fresh set of processing tools and a more refined workflow, and I’m really happy with how this one turned out. This is one of those targets that never gets old — the delicate filaments, the shock‑wave structure, and the way the colors weave together make it a perfect playground for narrowband imaging.

For this version, I leaned into a cleaner Ha/OIII balance to keep the structure crisp without pushing the colors too far. I also was able to capture a few, much cleaner Oiii frames. The OIII really shines in the outer arcs, giving that electric blue glow, while the Ha brings out the warm, detailed filaments running through the center.

This was captured with my AT102ED and QHY163M using Ha and OIII filters, and processed in Photoshop with my usual blend of curves, selective color, and star control. It’s always fun to see how much detail can be pulled out with just a bit of patience and a careful stretch.

I think this is my favorite Eastern Veil so far.