California Nebula in Ha + SII

November 15, 2020 - Reading time: ~1 minute

Tuesday night I captured 50 x 4-minute sub-exposures in Hydrogen-alpha for NGC 1499 (California Nebula) and last night I captured 60 x 240 second exposures in Sulfur 2 (SII), combining them here into a color image, with Ha in red, SII in blue, and each shared equally across the green channel of an RGB image. There just isn't any OIII (Oxygen) in the mix for this massive emission nebula in the Constellation Perseus. Gear notes: SkyWatcher EQ6-R Pro mount, William Optics GT81 Apochromatic Refractor 392mm at f/4.7, ZWO ASI1600MM-Pro monochrome camera, Astronomik 6nm filters, Raspberry Pi 4 4GB / 128GB running INDI/KStars/Ekos