Emission-line stars in the LMC: the Armagh survey and a metacatalogue

Aims. Accurate astrometry is required to reliably cross-match 20th-century photographic catalogues against 21st-century digital surveys. The present work provides modern-era identifications and astrometry for the 801 emission-line objects “of stellar appearance” in the Armagh survey (the largest of its nature to date). Methods. Targets have been individually identified in digital images using the Armagh Atlas and, in most cases, unambiguously matched to entries in the UCAC astrometric catalogues. Results. Astrometry with sub-arcsecond precision is now available for all the major photographic spectroscopic surveys of the LMC. The results are used to compile an annotated metacatalogue of 1675 individual, spectroscopically identified candidate Hα-emission stars, including detailed cross-matching between catalogues, and resolving many (though not all) identification ambiguities in individual primary sources