Here is your weekly reminder of Psalm 19 — the heart of Cygnus.

Also known as IC 1318 or the Sadr region, this nebula lies at the heart of Cygnus the Swan, a summer constellation in the Northern hemisphere. IC 1318 is an emission nebula, ionized by the radiation from a nearby hot star.

The bright star on the left is Deneb (Alpha Cygni) and the bright star on the right is Sadr (Gamma Cygni), neither of which are actually part of the nebula, but lie partway between Earth and IC 1318. These stars are clearly visible to the naked eye, but the emission nebula is too faint to be seen without long exposures on a telescope.

The pink patches are ionized hydrogen gas, and the dark streaks are dust-infused gas blocking visible light from view.

Image credit:Bill Mark.