The California Nebula is a large emission nebula stretching across almost 2.5 degrees of the night sky in the constellation Perseus. It has an apparent magnitude of 6.0 and lies approximately 1,000 light-years away. It was named the California Nebula because its shape is reminiscent of the outline of the US State of California on a map. The nebula has the designations NGC 1499 in the New General Catalogue and Sharpless 220 (Sh2-220) in the Sharpless catalogue of emission nebulae. The California Nebula stretches about 100 light years across. Even though it is large and has a visual magnitude of 6.0, the nebula is very difficult to observe visually because it has a low surface brightness. Its bright integrated magnitude is spread over a large area.

MENKIB...
The California Nebula is formed of gases that are ionized and made fluorescent by high-energy ultraviolet photons emitted from a young, hot, blue star in the vicinity. The massive star in question, Menkib (Xi Persei), is one of the hottest stars visible to the unaided eye. It shines at magnitude 4.04 from a distance of about 1,200 light years. Menkib is a blue giant of the spectral type O7.5III. It has a mass 26 – 36 times that of the Sun and has expanded to a size of 14 solar radii as it evolved away from the main sequence. The star shines with 263,000 solar luminosities (bolometric) with a surface temperature of 35,000 K. It is a member of the Perseus OB2 association. Menkib is an exceptionally fast spinner, with a projected rotational velocity of 220 km/s. The star’s estimated age is only 7 million years. Menkib has evolved quickly due to its high mass and will likely meet its fiery end as a supernova in the next million years.

Strange Fact: The California Nebula lies at declination 36° 25’ N, which matches the geographical latitude of the State of California. The nebula, therefore, transits in the zenith in the central part of California.

A SHOUT OUT TO MY GOOD FRIEND...
This image is a collaboration using 3 sets of data...
The aim of combining our data was to try and produce an image of NGC1499 that went beyond the usual presentation of mainly that part of nebula that resembles a map of California. We were interested in teasing out the surrounding dust and gas structures to get a more dynamic and scientifically more interesting panorama.
Two sets of data are from 2 of my NGC1499 projects using the widefield Redcat 51 and the 550mm Focal Length Esprit 100ed
The other is from my good friend Russell Discombe at Russell's Astrophotography using an Askar FRA400…
The image was created by matching the data whilst linear then processing individually. After star aligning the 3 completed images the stars were removed and the starless images carefully blended in Adobe Photoshop before adding the stars back…
Using this method I was able to combine the best parts of each dataset, about 8 hours work went into processing
There is a total of around 66 hours Narrowband data in total across the Ha, Oiii and Sii wavelengths...
Sii 19hrs
Ha 26hrs
Oiii 21hrs
The result was extremely satisfying and well worth the effort. The surrounding areas of NGC1499 proved to be full of interesting and dynamic structures including dust and gas lanes that appear to ‘sweep’ across the main nebula.

We named the image ‘Ignited by Menkib’ to celebrate the Blue Giant Xi Persei that ionises the gases of the surrounding nebula and makes them such an amazing spectacle to observe.

Clear Skies!
Olly

Image C - Starless