The Cocoon Nebula
The Cocoon Nebula (IC 5146) is a young stellar nursery located approximately 2,500 light-years away in the constellation Cygnus. Spanning about 15 light...
Frank Adler :: Astrophotography & Web Engineering
Hey there, I'm Frank. I create web experiences and capture the beauty of the universe.
Latest posts
The Dumbbell Nebula
Messier 27, also known as the Dumbbell Nebula, is one of the most striking planetary nebulae in the summer sky. It lies in the constellation Vulpecula...
ParallaxStarLayers: My First PixInsight Script
ParallaxStarLayers is my first PixInsight script. It separates stars from a processed astrophotography image into GAIA-based distance layers for parallax effects, videos, and interactive presentations.
An Evening About Light, Time, and the Art of Astrophotography
A behind-the-scenes look at astrophotography, from capturing faint starlight to creating the final image. Join me on June 19 in Chemnitz for questions, stories, and astronomy.
Skywarden Now Tracks the Sun
The latest Skywarden update adds the sun as a tracked object, brings golden hour planning to the app, and introduces full eclipse tracking - timed for the total solar eclipse crossing Europe on August 12.
H3X - Bringing back a gem
A nostalgic look back at Hexxagon, one of the DOS games that ran on my very first 386 PC - and why I ended up rebuilding it as a modern browser-based multiplayer game called H3X.
The Bubble Maker
WR 134 is a Wolf-Rayet star in Cygnus - a massive, extraordinarily hot star in a late and turbulent phase of its life. Wolf-Rayet stars are rare: only...
A Journey to the Stars — Astronomy Night at TU Chemnitz
I will give my first public astronomy talk at TU Chemnitz's Lange Nacht der Wissenschaften on May 9th, 2026 — a journey from comets and auroras to distant galaxies — alongside the Astro Stammtisch Chemnitz booth with solar and deep-sky observation from 14:00.
The Sunflower Galaxy
Lying roughly 27 million light-years away in Canes Venatici, M63 takes its popular name from the resemblance of its loosely wound, feathery spiral arms...
Sterne über Chemnitz - My First Exhibition
After years of sharing images online, my astrophotography is finally going on a wall. Emmas Onkel in Chemnitz, May 1st through July 31st 2026.
The Pacman Nebula
NGC 281, the Pacman Nebula, is an expansive star-forming region in Cassiopeia, roughly 9,500 light-years away. Its name comes from the distinctive shape...
The Planetarium Shines Again
On 28 March 2026, the school planetarium at Albert-Schweitzer-Oberschule in Chemnitz reopened after nearly a year of closure. A packed house, an uncooperative sky, and the clear sense that this place had been missed.
The Crescent Moon
At roughly 20% illumination, the waxing crescent reveals the Moon at its most dramatic. The terminator - the dividing line between lunar day and night...
The Leo Triplet
Some 35 million light-years away in the constellation Leo lies one of the spring sky's most iconic galaxy groups: the Leo Triplet, also known as the M66...
The Planetarium Awakens
The planetarium at Albert-Schweitzer-Oberschule Chemnitz is restarting. Join us for the Tag der Astronomie on 28 March 2026 – free planetarium shows, telescopes, and live views through the observatory. No registration required.
Messier 106
Messier 106 is no ordinary spiral galaxy. At 23.7 million light-years in the constellation Canes Venatici, a Seyfert II nucleus harbors a central black...
No Ads. No Paywall. Just a Request.
Skywarden and Theo are free and will stay that way. Here's what that means in practice — and why I ruled out every other option.
The Question Mark Nebula
Sharpless 171 is one of the most fascinating star-forming regions in the northern sky - a sprawling H II emission nebula in the constellation Cepheus,...
Meet Theo: I Just Needed a Theodolite
Skywarden gained support for detailed horizon profiles - but creating one required either expensive surveying hardware or apps that cost €20–30 for a task most astrophotographers do once or twice. So I built Theo: a free PWA that uses your phone's sensors and camera to capture azimuth/altitude pairs around the full 360° and export them as a .hrz file. This is the story of why it exists, how the…
Why I Switched Back to Claude
I spent some days on Codex after hitting Claude's limits. Then the Pentagon deal happened – and Anthropic said no while OpenAI said yes. Here's why I switched back.
AI-Assisted Development: One month in
After a month of building Skywarden with Claude Code, I've come to see AI-assisted development not as a replacement for good engineering - but as the next evolution of it.
Bye Astro Planner, hello Skywarden!
My astrophotography planning tool is growing up. Rebranding from Astro Planner to Skywarden, the app now features deep weather integration with safety alerts, a year-ahead planning mode with calendar exports, and dedicated presets for smart telescopes. Stop guessing what to shoot and start guarding your clear skies.
Astro Planner - a smarter way to choose what to shoot tonight
Astro Planner is an astrophotography planning tool that recommends deep-sky targets based on your setup, location, and sky conditions.
The Shark Nebula
LDN 1235 - better known as the Shark Nebula - is one of those targets that rewards patience more than aperture. In this new capture, the “shark” emerges...
A night to remember
On the night of Jan 19 - 20, the strongest aurora I’ve seen so far lit up the sky in vivid green, pink, and violet. Driven by an X1.9 solar flare and an Earth-directed CME, geomagnetic activity surged beyond Kp 8,67 (G4 on NOAA’s scale) and the main show peaked between 21:45 and 23:30. With a new-moon darkness and clear, cold air, the green curtains were even visible to the naked eye - and I ended…
The Monkey Head Nebula
NGC 2175, better known as the Monkey Head Nebula, is a beautiful emission nebula and open star cluster in the constellation Orion. The object sits in ...
The Flaming Star Nebula
Sh2-229, better known as the Flaming Star Nebula or IC 405, is a striking emission and reflection nebula located in the constellation Auriga. At a distance...
The Cave Nebula
Sh2-155, commonly known as the Cave Nebula, is an active star-forming region located in the constellation Cepheus, at a distance of approximately 2,400...
The California Nebula
This astrophotography image features NGC 1499, widely known as the California Nebula, a large emission nebula located in the constellation Perseus. The...
The Rosette Nebula
The Rosette Nebula is a vast and luminous star-forming region located approximately 5,000 light-years from Earth in the constellation Monoceros. Spanning...
The Pleiades
Nearly one year after my last wide-field capture of M45 , I returned to this iconic target with a narrower field of view and a focus on fine detail. This...
The North America Nebula
The North America Nebula (NGC 7000) is a vast H II region in the constellation Cygnus, instantly familiar for its likeness to the North American continent...
How to (not) build an Allsky Camera
After two failed attempts — one drowned by rain and another cooked by dew — I set out to build a smarter, more resilient allsky camera. This post shares how I created a waterproof 3D-printed housing, automated dome heating with weather-based control, and learned a few lessons about balancing hardware, software, and patience along the way.
Blocking AI Crawler Bots using robots.txt
While I follow the development of AI with a lot of interest, I do not want my work to be used for training these models. I just learned that it's possible to (at least try to) block AI bots from crawling a website using the robots.txt file.
The Wizard Nebula
NGC 7380, poetically known as the Wizard Nebula, is an enigmatic region of stellar creation and cosmic artistry located roughly 7,200 light-years away...
My first Top Pick on Astrobin
Yay, my composite image of the Lunar Eclipse above the Lulatsch in Chemnitz was just selected as a "Top Pick" on Astrobin 🎉
The Lobster Claw and Bubble Nebulae
NGC 7635, also known as the Bubble Nebula, takes center stage in this wide-field astrophotograph — offering a vivid showcase of dramatic star formation...
The Lion Nebula
This is Sharpless 132, better known as the Lion Nebula, a vast emission nebula lying in the rich starfields at the southern border of the constellation...
HTT 2025 – Part 3: Bye And See You Again
The final morning brought a peaceful end to a weekend full of astronomy and friendship. After a much quieter night free from mosquitoes, I found myself both eager and reluctant to pack up our gear. Reviewing the night’s images while still half-asleep, I was grateful to see the skies had cleared and allowed for some last-minute shots of the Bubble Nebula. Saying goodbye to Ronald and the new…
HTT 2025 – Part 2: So Close to the Sun
This Saturday at the Herzberger Teleskoptreffen was a mix of challenges and unforgettable moments: from a restless mosquito-filled night to breathtaking views of the sun through H-alpha telescopes, and the peaceful charm of Jeßnigk’s village life. Despite weather hurdles and technical setbacks, the experience deepened my passion for astrophotography and stargazing, reminding me that each night…
HTT 2025 – Part 1: Now or Never!
In pursuit of a long-awaited father-son road trip, I found myself racing daylight to the Herzberger Teleskoptreffen — our van packed with excitement, telescopes, and hope for clear skies. As we set up camp beside familiar faces and under a darkening Brandenburg sky, a sense of adventure took over. With the Milky Way shimmering overhead and the thrill of finally capturing Sh2-132, the night blended…
Lunar Eclipse above the Lulatsch
Chemnitz Under the Blood Moon On September 7th, 2025, the skies over Chemnitz delivered an unforgettable astronomical spectacle: a total lunar eclipse...
The Clamshell Nebula
This is Sharpless 119, poetically known as the Clamshell Nebula, residing in the constellation Cygnus approximately 2,200 light-years from Earth. Often...
The Elephant's Trunk Nebula
Stepping into this frame feels like drifting through a quiet storm of gas, dust, and newborn stars. Center stage is the Elephant’s Trunk Nebula, a sinuous...
The Ghost of Cassiopeia
Floating in the royal constellation Cassiopeia, this wispy apparition is IC 63—often called the Ghost of Cassiopeia. It’s a faint, billowing cloud of ...
Astrophotography - Is it Art?
Recently, I set out on a personal quest to find an art gallery willing to showcase my images - a journey filled with both anticipation and challenges.
The Crescent Nebula
Astrophotography often leads us to stunning cosmic vistas hidden in plain sight among the stars. My latest adventure brought me face to face with the ...
The Flying Bat & Squid Nebulae
The Flying Bat Nebula, cataloged as Sh2-129, is a large, relatively faint emission nebula located in the constellation Cepheus, about 2,300 light-years...
Astronomy meets TU Chemnitz
For TUC Tag 2025, a friend and me did an astronomy roadshow at TU Chemnitz, exhibiting our photography, explaining telescopes and doing some live astronomy.
The Heart & Soul Nebulae
This is my biggest imaging project so far, I never worked with this much data before. It's a mosaic of my recent captures of the Heart and Soul Nebulae...