Most of the nebulae I image are relatively hot, but dark nebulae like the Seahorse are cold, typically in the range of  -263 to -173 degrees Celsius. They’re still regions of star formation though, although they absorb the light from newborn stars, as well as blocking light from background stars, and hence appear dark.

The official name of the Seahorse Nebula is B150. The B is from Edward Emerson Barnard, an American astronomer who studied dark nebulae. These were thought to be voids in the sky, but Barnard used photographic plates to show that they were actually dusty areas blocking background light. In 1919 he published a catalogue of 189 dark nebulae, of which the Seahorse Nebula was number 150.

Images of the Seahorse taken from proper dark skies show it with a brownish-hue, but I wasn’t able to get that. Perhaps the brown would have shown up better with a much longer integration time. Still, I’m happy to have captured the ethereal glow around the Seahorse.