It’s an honour to be featured as the NASA Astronomy Picture of the Day. Thanks so much to all the staff behind the APOD page for all their daily work.
The chosen image was one of the last images from my former backyard observatory located in Prades where I have captured deep sky images since 2015. Last 2022 I moved to a new backyard with more space, two piers, three telescopes and a domotic roll-off roof that allows me to control all the setup remotely. I live in the same observatory that is actually our home in the Bortle 4 village of Prades. See our outreach project @ parcastroprades
In a special moment like today, I would like to thank my wife  for all her dedication towards our home observatory and my work. She is the best at DIY and solves every single problem that I can’t figure out how to deal with. A special mention to my family, friends, and all the other great astrophotographers that join the Sabadell Astronomical Club. And a big thanks to Jordi Vargas, who has been working hard in my new backyard to do a professional job with all the things we did not know how to solve.
About the image:

Not far from Sirius, the brightest star in the night sky, this cosmic scape shows the effects of several energetic events blown by the massive Wolf-Rayet star WR 6, located in the Cannis Majoris constellation.

Sharpless-308, also known as the Dolphin Nebula, seems to dive towards a Cosmic Reef, the HII region catalogued as Sh2-303. According to a 1982 study, this nebula is ionised by the Wolf-Rayet star WR 6 along with Sh2-304 and Sh2-308, also called the Dolphin Nebula. A look at this region in Ha suggests that Sh2-303 is the brightest part of a ring that appears to surround several B class giant stars, including LS92 (B2/3 III) and HD 51200 (B2 III/IV). So it seems as though WR 6 may not be the only ionising star for this nebula.

The Dolphin Nebula itself it’s a faint nebula created by a massive Wolf-Rayet star; the bright star near the center of the nebula, known as EZ Cannis Majoris, EZ CMa or WR 6. These massive stars can have 20 times the mass of the Sun, and are thought to be a pre-supernova phase.

This bubble-shaped nebula lies some 5,200 light-years away from Earth and it covers a diameter of 60 light-years. That corresponds to a similar angular diameter as the Full Moon. It can be seen towards the constellation of Canis Majoris.

This deep sky object it’s quite difficult to be captured from the northern hemisphere locations due to its low altitude. From my home location, where all the images were taken, it only rises some 24º above the horizon when it passes through the meridian. That implies being affected by the southern horizon light pollution. Even though I live in the south of Europe (Prades, Tarragona – Spain) in a quite dark location (Bortle 4), it’s at the limit of my technical capabilities.

I struggled to get as much data as I could with my dual Takahashi FSQ setup during several full moon January 2022 nights. For the nebula structure I used a 3nm Ha filter in front of my ASI2600M and FSQ106 EDX4 and also a 6,5nm [OIII] filter on the FSQ85 with the smaller ASI294MM sensor. RGB images were captured by the FSQ106 to create the starfield image in natural color.

A special mention to Astronomy Picture of the Day and for their excellent pages that helped me to document the text above.

This image has been shortlisted in the Astronomy Photographer of the Year 2022 (Stars and Nebulae).

The image got the third prize in the Astronomy Photographer of the Year 14 (2022 edition) Public’s Choice Award.

Link to the spanish edition of National Geographic:

The image has been the NASA Astronomy Picture of the Day the 29th of March 2023:

Thanks for taking your time on this site.

Image Details


Ha 167×600″ (27h50′)

RGB: (18,18,15) x 300″ (4h15′)


[OIII]: 320×300″ (26h40′)


Calibrated with darks, flats and dark-flats.


Total exposure: 58h45′


Moon at 85% (on average)

Image resolution: 1.46”/pixel

FOV (full image): 2º18′ x 1º33′


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, 29th of March 2023.
Prades (Tarragona, Catalonia – Spain).


Full HD view on Astrobin:


error: Image protected by copyright.