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.

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.

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 up capturing it all on my iPhone because my camera wasn’t charged.

My year in astrophotography - 2025

This astrophotography image features NGC 1499, widely known as the California Nebula, a large emission nebula located in the constellation Perseus. The nebula lies approximately 1,000 to 1,500 light-years from Earth and is one of the most impressive wide-field deep-sky objects in the northern night sky. NGC 1499 earned its nickname due to its elongated shape, which closely resembles the outline of the U.S. state of California when captured in long-exposure images. With an apparent size of nearly 2.5 degrees, the nebula spans about five times the diameter of the full Moon, corresponding to a physical length of roughly 100 light-years. The California Nebula is classified as a H-II region, consisting mainly of ionized hydrogen gas. It emits light predominantly in the H-alpha wavelength (656 nm), making it an ideal target for narrowband astrophotography. The nebula’s glow is powered by intense ultraviolet radiation from the nearby hot O-type star Xi Persei (ξ Persei, Menkib), which excites the surrounding hydrogen gas and causes it to shine. This image highlights the nebula’s delicate filamentary structures, faint outer regions, and complex dust lanes embedded within the glowing hydrogen clouds. These features reveal dynamic interactions between stellar radiation, interstellar gas, and dust - key processes linked to star formation within our galaxy. Discovered in 1885 by astronomer Edward Emerson Barnard, NGC 1499 is now considered a classic target in astrophotography. Due to its large size and low surface brightness, it is difficult to observe visually but reveals remarkable detail in long-exposure, H-alpha, and deep-sky imaging. The California Nebula is best photographed from the Northern Hemisphere during autumn and winter under dark skies.

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.

Yay, my composite image of the Lunar Eclipse above the Lulatsch in Chemnitz was just selected as a "Top Pick" on Astrobin 🎉

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 Cepheus. Though often overlooked for its visual subtlety at the eyepiece, through careful astrophotography the nebula’s intricate “lion’s head” silhouette and glowing cosmic gas clouds come to life, revealing one of the Perseus Arm’s most spectacular hidden treasures. ## Sculpted by Massive Stars At the core of Sh2-132 stand two extraordinary Wolf-Rayet stars (HD 211564 and HD 211853), alongside a hot O-type star and a cohort of youthful B-type suns. These stellar titans emit intense ultraviolet radiation and powerful stellar winds that energize, shape, and carve the surrounding hydrogen-rich nebula, forming the filaments and arc-like “mane” features for which the region is known. A pair of bubble-like shells — remnants of past stellar outbursts — can be traced in both radio and optical images, evidence of the turbulent, ongoing interplay of gas, dust, and starlight. ## A Symphony of Color and Structure The Lion Nebula’s vibrant palette is mapped in this HSO (Hubble Space Telescope) style image, pairing hydrogen-alpha (Hα) and sulfur-II (SII) emissions in warm reds and oranges with the emerald glow of doubly ionized oxygen (OIII). Dark lanes — catalogued as Barnard 369 — add striking contrast by absorbing background light, creating the illusion of the lion’s facial contours amidst the glowing background. With an apparent diameter nearing 40 arcminutes and a physical span of up to 250 light years, this region teems with architectural complexity: knots, globules, and absorption dark clouds alternate with shining clusters of newborn stars — clear evidence of a vibrant, but now mostly dormant, site of star formation. ## A Celestial Sculpture in Cepheus Located roughly 10,000 light-years from Earth in the Perseus Arm, Sh2-132 lies near the Lacerta border, in a region graced by open clusters and punctuated by enigmatic dark clouds. Though less renowned than some of its Cygnus neighbors, the Lion Nebula exemplifies the grandeur and drama of interstellar matter reshaped by massive stars — and offers a captivating canvas for astronomers and astrophotographers alike.