When authors omit specific source positions from their articles, they must presume that the position is common knowledge, to be found in the appropriate standard catalog. When no such position can be obtained by the editors, all such entries are sorted alphabetically by source name and are listed at the end of the catalog. LII The galactic longitude of the object. The galactic latitude of the object. Edition Edition Number.
Nominal positions indicate a general area in the sky.
Aperture beam size. In addition to being a factor in source brightness calculation, beam size can be used as an aid in determining positional coincidences and identifications with other sources, and as a first-order indication of positional accuracy. Aperture beam units. For spectra the starting wavelength of the spectrum. Note that some entries have a wavelength range outside the 1 micron-1 mm range.