The Merope Nebula is a part of the Pleides star cluster (M45). This open cluster of stars is currently moving through interstellar dust which is what causes the wonderful blue nebulosity around the primary stars.
The Merope Nebula (which the big nebula you see in this image) shouldn't be confused with Barnard's Merope Nebula which is considerably smaller and very close to Merope (the star). In fact, in my image, you can make out Barnard's Merope Nebula, its the slightly brighter area just below the main star. The finest image I've seen of this nebula was taken with the Hubble Space Telescope.
I am very pleased with the quality of this image. The combination of low noise and high resolution probably makes it one of my finest astro images. I can't wait to make a giant print of this one.