The Wackerling Catalog contains entries for 5326 early-type emission-line stars. Of these stars, 1424 have no spectral classification but are assumed to be of early type. Some 71 percent of the stars in this catalog can also be found in the Mount Wilson and the Mount Wilson-Michigan survey catalogs. The Wackerling Catalog contains numerous cross identifications to other designations (common name, HD, DM, LS, MWC, TON, HIL, WRA, HEN, etc.), rough spectroscopic types, magnitudes (visual and blue), and positions. The version of the Wackerling Catalog on which the HEASARC database is based was obtained from the ADC and differs in some respects from the original published version, notice. This online catalog was originally ingested by the HEASARC in July 1999, based on a machine-readable table obtained from the ADC/CDS data centers. It was updated in May 2020 to reflect updates to the spect_type_code values made by the CDS for improved database compatibility. This is a service provided by NASA HEASARC .