This is a molecular cloud in the Andromeda constellation. There is a faint reflection nebula, VDB 158, at the top end of the checkmark structure. The entire area is difficult to image unless done away from significant light pollution. There are a couple galaxies that show up in the background, seen easier in the starless version. Speaking of the starless version, it really shows the faint dust in the surrounding area, and thumnail used for this is a grayscale version.
Click the image for a larger version
Taken with my Z61, ASI 183MC Pro, and GEM28 mount
Starless version of above image