It is just a small nebula that lies about 0.06 light years from Merope star (bright one in the center). It is quite a difficult object, because it is well hidden in the bright light from the illuminating star.
Picture has been taken during Pleiades exposition – it is ten exposures, each one lasted 30 seconds. Current setup: TS 130/910 0.79x, Atik383 with L Baader filter. Image is crop resized 150%, so the scale is 1″/px.