TCS worklists for A0V standard stars. Pick the list with the dimmest magnitude you are willing to use, load it into the TCS and you can use it to find the nearest standard stars to your science targets.   See http://snoopy.as.utexas.edu:8080/OS/manuals/2.7m-telescope/tcs/appendix/worklists for instructions on how to use worklists on TCS.