This two-panel mosaic from my Texas telescope shows the central part of the California Nebula measuring around three moon widths or 90 arc minutes. In total the nebula is around 145 arc minutes visually which is pretty big.

The blue OIII signal is very weak and when I tried to capture it my light polluted London garden, I could see no trace of it in the individual sub frames. It still took 10 hours of OIII in under a Bortle 1 sky to bring out its more subtle variations.

I’ve processed this with bright colours which I don’t normally do. But in this instance I think it creates a more striking image and emphasises the details of the billowing dust.

This is also known as the California Nebula due to its similar shape to the US state.

Telescope: ZWO FF107 Camera: ZWOASI2600MM Pro

Ha 90x300 OIII 116x300 SII 104x300 Total exposure 25hrs 50mins