CALIFORNIA NEBULA (NGC 1499) in NARROWBAND

The California Nebula (NGC 1499) is an emission nebula located in the constellation Perseus. It is so named because it appears to resemble the outline of the State of California. It is almost 2.5° long on the sky, yet extremely difficult to observe visually. It's located about 1000 light years from earth in the Orion spiral arm of the Milky Way galaxy (where our Solar System is also located).

The California Nebula contains a hot blue-white star named Menkib (top right), by far the brightest star in this image. Menkib is one of the hottest stars visible in the night sky; its surface temperature is about 37,000 Kelvin (about 66,000 degrees Fahrenheit, or more than six times hotter than the Sun).

Menkhib, which is receding from us at about 20 kilometers per second, is part of an association of very hot stars that were born from the California nebula only a few million years ago. These massive and luminous stars are lighting up the nebula, as well as heating and ionizing it. In visible light, the ionized gas glows red, while in infrared light we see the heated dust.

I spent several nights capturing the image, just over 15 hours total of data acquisition. Seeing was quite good all evenings, as there was great transparency to see through to the nebula. The image was color assigned using Hubble Palette, preliminary processing and calibration was done with APP and final processing was done with Pixinsight and Lightroom.

OTA: Askar 140APO Triplet Refractor (140mm aperture, using 1x flattener, f/7, 980mm focal length)
Mount: iOptron CEM70
Camera: ZWO ASI6200MM Pro (full frrame)
Gain: 100
Cooling Temperature: -10 degrees celsius

Filters (Chroma 3nm):
Sii 🟢 74 x 180s = 3.7 hrs
Ha 🔴 89 x 180s = 4.5 hrs
Oii 🔵 138 x 180s = 7 hrs
15.2 hours total acquisition time

Auto-guiding: ZWO ASI174MM Mini and ZWO OAG-L
Auto-focusing: ZWO EAF
Control: ZWO ASIAIR Pro

Calibrated in Astro Pixel Processor with flats, darks and dark flats. Processed in Pixinsight and Lightroom.