Pan: Hidden in a dark cloud

The subject of this week’s Picture of the Week from Hubble is the spiral galaxy IC 4633, located 100 million light-years away from us in the constellation Apus. IC 4633 is a galaxy rich in star-forming activity, as well as hosting an active galactic nucleus at its core. From our point of view, the galaxy is tilted mostly towards us, giving astronomers a fairly good view of its billions of stars. However, we can’t fully appreciate the features of this galaxy — at least in visible light — because it’s partially concealed by a stretch of dark dust. A vast, narrow trail of faint gas that snakes over the southern celestial pole, this cloud overlapping IC 4633 has been called the South Celestial Serpent.