How is GALEX Object Nomenclature determined?
The GALEX Project generates a 19-digit GALEX “object identifier,” which is not unique for a given object. For example, it may be named twice if it lies within an overlap region of two sky tiles or has been observed in two visits. Since the GALEX pipeline software does not have a unique name for a given extracted object, it cannot associate it with a stable name over multiple data deliveries. The names MAST denotes are taken from the RA/Dec position from the centroid position in the current data release and are truncated to 0.1 second in RA and to the second in DEC. Thus, there is a finite probability that the coordinates within a given object’s “name” will change minutely for a subsequent delivery. Final names will be given to GALEX objects when a final catalog of object positions is generated after the end of the mission. In the meantime, MAST recommends that authors utilize its posted names in publications for which a GALEX name is needed.
