Capturing the Cosmos from the City: Carlos Butrón’s Astrophotography Journey

I’m Carlos Butrón (@urbanmajortom), based in Barcelona. With a background in Computer Science, I recently discovered astrophotography and quickly became fascinated by the possibility of capturing the universe from the city.

Like many others, I had always been curious about the cosmos, but it wasn’t until September that I bought my first telescope and took my first step into this world. I started capturing images in November, learning from scratch and trying to understand both the sky and the data behind it.

In January, I began using the Seestar S30, followed shortly by the S30 Pro in February. Coming from other ZWO equipment within the same ecosystem, the transition felt natural. What impressed me most was how accessible and efficient the process became, especially under urban skies.

Imaging from Barcelona under Bortle 8 skies is challenging, but that is also part of the motivation. I am particularly interested in exploring what can be achieved under these conditions by pushing integration time and improving processing techniques with PixInsight.

For me, astrophotography is not just about images, but also about understanding and learning. It is a way of approaching the cosmos and reflecting on who we are, and on how small, fragile, and precious our place within it really is.

Horsehead Nebula (Barnard 33 / IC 434)

The Horsehead Nebula is a dark nebula in the constellation Orion, located about 1,375 light-years away. Seen in silhouette against the bright hydrogen emission of IC 434, it is one of the most recognizable dark nebulae in the night sky.
Captured over multiple nights from Barcelona under Bortle 8 skies | Seestar S30 | 456 × 30 s exposures — 3 h 48 m total integration | Stacked, calibrated, and processed with PixInsight.

The Orion Nebula is a vast H II region in the constellation Orion and one of the nearest massive star-forming regions to Earth. Located about 1,350 light-years away, it is illuminated by the young stars of the Trapezium Cluster and shows bright hydrogen emission mixed with dark dust lanes and extended surrounding nebulosity.
Captured from Barcelona under Bortle 8 skies | Seestar S30 Pro | 212 × 30 s exposures — 1 h 46 m total integration | Stacked, calibrated, and processed with PixInsight.

M45 — The Pleiades

The Pleiades, also known as Messier 45, is a bright open star cluster in the constellation Taurus and one of the closest and most recognizable deep-sky objects in the night sky. Located approximately 440 light-years away, it is surrounded by faint blue reflection nebulosity caused by interstellar dust scattering the light of its hot young stars.
Captured over three nights from Barcelona under Bortle 8 skies | Seestar S30 | 460 × 30 s exposures — 3 h 50 m total integration | Stacked, calibrated, and processed with PixInsight.

Whirlpool Galaxy (M51)

The Whirlpool Galaxy is a grand-design spiral galaxy in the constellation Canes Venatici, located about 25–31 million light-years away. Its gravitational interaction with NGC 5195 distorts the spiral arms and triggers regions of active star formation.
Captured over three nights from Barcelona under Bortle 8 skies | Seestar S30 | 541 × 30 s exposures — 4 h 30 m total integration | Stacked, calibrated, and processed with PixInsight.

M101 (NGC 5457) — The Pinwheel Galaxy

M101 is a grand-design face-on spiral galaxy in the constellation Ursa Major. Located about 21 million light-years away, it is one of the largest and most prominent spiral galaxies in our nearby universe. Its vast disk contains numerous bright H II regions and young star clusters spread along its asymmetric spiral arms.
The Seestar is also capable of capturing several other galaxies across the field, including distant background galaxies such as NGC 5422, located around 100 million light-years away.
Captured over 10 h 10 m total integration: 8 hours from Barcelona under Bortle 8 skies, and 2 hours from Observatori de Pujalt under darker rural skies (approximately Bortle 4) | Equipment: Seestar S30 Pro | 1220 × 30 s exposures — 10 h 10 m total integration | Stacked, calibrated, and processed with PixInsight.

Rosette Nebula (NGC 2237–2246)

The Rosette Nebula is a large H II region in the constellation Monoceros, associated with the young open cluster NGC 2244. Located about 5,200 light-years away, this stellar nursery is dominated by hydrogen emission, with oxygen and sulfur structures present in the inner regions.
Captured over three nights from Barcelona under Bortle 8 skies | Seestar S30 Pro | 582 × 30 s exposures — 4 h 51 m total integration | Stacked, calibrated, and processed with PixInsight.

All images were acquired in Live Preview mode with dew control enabled, saving individual 30-second sub-exposures for subsequent calibration, stacking, and processing in PixInsight.