How often is NED updated?
A.: Usually three or four times a year. A backup working copy of the database is continually updated and checked for problems and errors before being released. • Q.: How complete is NED? A.: We have tried to get all data published since 1988 into the database, but we invariably miss some and probably have errors as well. We are also constantly changing and refining the Basic Data so you may not always see the same data from month to month (although if the change is large we will generally include a note to that effect). Also, we scan the refereed literature only in the larger professional journals. Thus, if data are published only in an observatory monograph, only in preprint, only in a conference proceeding, or only in a thesis, we may well not see it. In these cases, we are happy to add the data to NED when you bring it to our attention. • Q.: Are the redshifts reported in NED spectroscopic or photometric? And what do the codes following the redshift mean? A.: We adopt spectroscopic
A.: Usually three or four times a year. A backup working copy of the database is continually updated and checked for problems and errors before being released. • Q.: How complete is NED? A.: We have tried to get all data published since 1988 into the database, but we invariably miss some and probably have errors as well. We are also constantly changing and refining the Basic Data so you may not always see the same data from month to month (although if the change is large we will generally include a note to that effect). Also, we scan the refereed literature only in the larger professional journals. Thus, if data are published only in an observatory monograph, only in preprint, only in a conference proceeding, or only in a thesis, we may well not see it. In these cases, we are happy to add the data to NED when you bring it to our attention. • Q.: Are the redshifts reported in NED spectroscopic or photometric? And what do the codes following the redshift mean? A.: We adopt spectroscopic
