IAU Meteor Database of photographic orbits – version 2003

The IAU Meteor Data Center in Lund has acted as a central depository for meteor orbits obtained by photographic, video and radar techniques. The database of precisely reduced photographic meteors contains data on 4581 meteor orbits obtained by 17 different stations or groups in the period 1936–1996. The orbital and geophysical data are available in two separate files as well as in an alternative file with the merged data. In various studies of meteoroid streams as well as in studies of the sporadic meteor background, it is often necessary to utilize both the orbital and the geophysical data files. Since the database is a compilation of partial, not perfectly compatible catalogues from many observing stations, the merging of parameters from one data set to another may sometimes present problems. The present contribution is a note on some problems encountered in the merging procedure. Moreover, it is evident that the database includes a small amount of erroneous data – either in the observations or in the subsequent data reductions. The latter error is not surprising in view of the lack of modern computers at several stations in the past. A final, corrected version of the IAU MDC Lund photographic meteor orbits (eq. 2000.0) can now be requested through the homepage of the Astronomical Institute, Slovak Academy of Sciences (http://www.astro.sk/~ne/IAUMDC/Ph2003/database.html).