Faculty members become faculty emeriti upon their retirement as tenured faculty members and the Board of Trustees action regarding the retirement. No action is needed on the part of a retiring faculty member for emeriti status. See AR 2:1-1, p. 3, for additional information, which includes various rights and privileges of emeriti faculty.
There is an Association of UK Emeriti Faculty, which is a membership group that holds luncheons, awards fellowships and keeps you connected to the university. This group should be in touch with newly retired faculty members regarding membership in the association. For more information about the association, see http://www.uky.edu/UKAEF/index.htm.
To be a professor emeritus of UK, one must retire from UK as a tenured faculty member. Faculty teaching at UK who then move to another institution upon retiring are professor emeriti of their last institution. Use emeritus when referring to men, and emerita for women. Emeritae is the plural feminine form; emeriti is plural for a group of men, or a group of men and women. This is an honorary title that corresponds to the faculty appointment level last held during active service.