Last fall I captured several tens of hours of images on the Triangulum galaxy, Messier 33. I used the popular broadband approach (LRGB), but also gathered more than 100 hours in narrow band filters in order to see the star forming regions and rich nebulae in this neighbouring galaxy.  The image also shows some IFN around M33.
The resulting image has more than 150 hours of exposure captured from my backyard, located in a Bortle 4 dark sky in the south of Barcelona.
I highlighted a faint nebula detected in the [OIII] and Ha channels that I did not find in any catalogue.
I’ve worked with professional astronomers in order to confirm the discovery. Dr. Raúl Infante (Centro de Estudios de Física del Cosmos de Aragón) and Judith Àrdevol (Universitat de Barcelona). We three have worked hard to confirm the discovery that has been published in the Reserach Notes of the American Astronomical Society. The name of the nebula is Roig1 Prades Sky .

This is my personal tribute to my grandfather, Jaume Roig, who introduced me to astronomy when I was a little child some 35 years ago. And also a tribute to Prades and its dark sky, the village I love and live with my wife Georgina Serven. We two work at Parc Astronòmic Muntanyes de Prades, a project that works for the protection of the dark sky, for the diffusion of astronomy and the promotion of the research.


Roig1 Prades Sky coordinates:

Center (RA, hms):    01h 34m 25s
Center (Dec, dms):    +30° 20′ 17″


Thanks for taking your time on this site.

Image Details


L: 271 x 300″ (22h 35′)

Ha: 534 x 300″ (44h 30′)

RGB: (24 x 300″) x 3 (6h)



[OIII]: 969 x 300″ (80h 45′)


Calibrated with darks, flats and dark-flats.


Total exposure: 153h 50′


Moon at 30% (on average)

Image resolution: 1.46”/pixel

FOV (full image): 2º 23′ x 1º 34′


FSQ106 EDX4 + ASI2600MM + LRGB Astrodon filters + Ha3nm Antlia – with ZWO EFW 7 pos

FSQ85 + ASI294MM + SHO LRGB Baader filters – with ZWO EFW 8 pos

Mesu200 mount

Guiding with ASI120MM and ZWO Mini Guide Scope



Aleix Roig, November 2023 / April 2024
Prades (Tarragona, Catalonia – Spain).

Full HD image on Astrobin.

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