The Shark Nebula

A shark glides through the luminous current of the Milky Way. Its silhouette stands out dark against a teeming background of stars: that is what earned it its nickname. In reality, this predator is a great cloud of cold dust, set in the constellation of Cepheus.

It is a dark nebula: its dust is so dense that it hides the stars behind it, and it is this shadow that draws the shark's body. Its distance remains poorly known, somewhere around 650 light-years according to the most common estimates, for a beast some fifteen light-years long.

But the shark is not entirely black. In places, where young hot stars are buried in the dust, it reflects their light in a bluish veil: small reflection nebulae that light up the creature's neck and head. A very faint object that reveals itself only through long hours of exposure under a dark sky.

Far behind the shark, the long exposure also brings out a galaxy: PGC 67671, a barred spiral seen face-on, millions of light-years away.