LDN 673 is a located about 600 light years away in Aqulia and is a dark cloud complex. The clouds have temperatures between 10 and 100K which allows hydrogen atoms to form molecular hydrogen, a common ingredient for star formation. Evidence of star formation is seen from the presence of the Herbig Haro object HH32. These objects form when high speed jets of partially ionised gas ejected by stars collide with nearby gas and dust.
The clouds tend to make the stars behind the object look reddish, whilst the densest regions completely blocks starlight. By contrast, the blue starlight from the nearer stars interacts with the dust and gas to create a bluish haze.