Unlike the US state that shares its name and general shape, the California Nebula is beautiful, being a large emission nebula in the winter constellation Perseus. The nebula is large, bright and close to us, at only around 1,500 light years away, but is notoriously difficult to see through the eyepiece, since it’s brightness is spread out over nearly 3 degrees of sky, or nearly 6 full moons.
This nebula, like other emission nebulae, glows due to the stars it contains ionizing the gas around them, making it glow, mainly in H-alpha (red) and H-beta (teal-blue) wavelengths. Much of that ionization is due to the bright blue giant star close to it (directly above it in my photo), named Menkhib, a star formed from the gas and dust of the California Nebula only a few million years ago, and which has since proceeded to floor it away from home at over 144,000 mph.
Recent (2020) observations of this nebula found that it contains interesting molecules such as ethenone (C2H2O), nitroxyl (HNO) cyanoacetylene (HC3N), cyclopropenylidene (C3H2), and isocyanic acid (HNCO), as well as deuterated molecules such as deuterated cyanoacetylene (DC3N) and deuterated thioformaldehyde (D2CS), indicative of active deuterium chemistry happening in this nebula.