Tom Bisque explains this.
Peter M.
"The pattern is caused by the diffraction spikes of the telescope used to create the data.
http://www.bisque.com/tom/catalog/catalog.asp
"Specifically the link GSC diffraction Spikes shows an example of this. However the GSC data is not the only stellar catalog with this issue. Even the NOMAD dataset used with TheSkyX is prone to this but in that case there is a flag used to indicate when the data is in fact not valid but rather caused by the telescope's diffraction spikes which hold the secondary optics."
DSS image (60x60 arc min) attached.
PS also look for the non real stars that form the outer halo in a screenshot from SkyX.