Northern Logoon Nebula (NGC 7538)
NGC 7538 (Sh2-158), near the more famous Bubble Nebula, is located in the constellation Cepheus. It is located about 9,100 light-years from Earth. It is home to the biggest yet discovered protostar (NGC 7538 S) which is about 300 times the size of the Solar System. It is located in the Perseus Spiral Arm of the Milky Way and is probably part of the Cassiopeia OB2 complex. It is a region of active star formation including several luminous near-IR and far-IR sources. Stars in NGC 7538 are mainly low-mass pre-main-sequence stars.
This image was created combining long exposed Ha images together with luminance images as luminance. North is up in this image. You can find an annotated version here.
[description from Wikipedia]