The area reproduced on the picture above lies just on the border between the constellations Cassiopea and Cepheus. Many objects are imaged here: at the center is NGC7635 (The Bubble Nebula). At upper left is M52 (NGC7654), an interesting open cluster containing 120 stars. At right of the Bubble is visible NGC7538, another emission nebula. At lower right are located Sh2-157, a large and faint emission nebula, of wich the brightest part is Sh2-157a (the red knot embedded into the nebulosity), and NGC7510, an open cluster formed by 100 stars. The border between Cassiopea and Cepheus pass vertically in the middle of Sh2-157.