APOD: 2024 September 19 - The Dark Seahorse of Cepheus

Good morning, Rallypoint, and welcome to the September 19th edition of Astronomy Picture of the Day (APOD). The Seahorse Nebula is ~1,200 light years from Earth in the constellation Cepheus. It is a dark (or absorption) nebula, and is so dense that it obscures the visible wavelengths of light from objects behind it. Dust particles within the nebula are coated with frozen carbon monoxide and nitrogen, which effectively blocks the passage of light at visible wavelengths.

Also known as Barnard 150, the Seahorse Nebula is one of 182 such dark nebulae cataloged by American astronomer Edward Emerson Barnard in 1919.