Improved astrometry for the Bohannan & Epps catalogue
  Aims: Accurate astrometry is required to reliably cross-match 20th-century
catalogues against 21st-century surveys. The present work aims to provide such
astrometry for the 625 entries of the Bohannan & Epps (BE74) catalogue of
H$\alpha$ emission-line stars. Methods: BE74 targets have been individually
identified in digital images and, in most cases, unambiguously matched to
entries in the UCAC4 astrometric catalogue. Results: Sub-arcsecond astrometry
is now available for almost all BE74 stars. Several identification errors in
the literature illustrate the perils of relying solely on positional
coincidences using poorer-quality astrometry.
