An example of the effect of the cross-matching step that is carried out on source catalogs of fields in which potential stellar overdensities have been identified. Sources in the field are cross-matched with Gaia and SDSS catalogs in order to identify and remove contaminating foreground objects (Galactic stars) and background objects (galaxies and AGNs) from our star lists. Sources that are retained are shown with black points, and sources that are removed are shown with red points. In this example field, approximately one-third of the objects in our original source list were removed as likely Galactic stars and ∼10% were removed as likely background galaxies or AGNs; these percentages are fairly typical, although the exact proportions of foreground and background objects and remaining point sources depend on quantities like the Galactic latitude and exact detection limits of each set of images.