The ADC archive contains data in the form of numerical tables. It does not contain pictures. (Links to several useful sources of astronomical pictures are included on the Amateur page .) At present, it contains very little solar data. It contains little about the planets except for positions and motions. It contains no text except that useful for understanding the tabular data. It is not possible to search for a specific set of data such as the 100 nearest stars. (However, see the ADC FAQ.)
Words in Catalog Descriptions search: You can search the contents of all the ReadMe files, using our archive search engine, Isite Z39.50 software from CNIDR. This includes the complete reference and author list. However, the names of the journals and some other words are abbreviated in the references using the standards in Astronomy and Astrophysics Abstracts. Thus, the complete name of the journal will not be found. Although the names of authors will be found, it may be more satisfactory to use the search against the lead author's last name to avoid listing catalogs by someone referenced in the document who is not the author. A catalog may be searched by title. However, as words such as "the" or "astronomical" add little to narrow the search, it may be easier to use just one or two words. Users can select whether all terms must be matched (the default) or at least one term must match (a Boolean "or" operation). Users can specify right truncation (wildcards) by ending a word with the ('*') wild card character. This tells the search engine to search on words matching the characters before the '*' and to ignore any trailing characters. For example, you might use right truncation in a query such as "spec*", which may retrieve documents containing the words: spectra, spectrophotometric, spectroscopic, spectrum, etc. It is often difficult to guess the exact form in which words will appear in a document. Therefore, each document contains one or more key words from a restricted set, called ADC_Keywords . Using one or more of these will normally make the search more efficient. There is also an author index . Clicking on one or more of these will provide a list of the appropriate catalogs and will often make the search more efficient. Most catalogs contain many objects. These are not normally listed in the document and hence will not be found by a search. A few, mainly in journal files, that refer to only one or several objects may be found. Thus, a search for P Cyg or P Cygni is more likely to return a list of catalogs of objects with P Cygni lines than those that contain the star itself. Newer documents have BibCodes that can be used for the search, e.g. 1993SAAOC..15...78K, K is the first letter of the last name of the first author. Also remember "stop words", words so common that they occur in almost every document are not used for searching a document.
Lead Author's Last Name: By taking advantage of the structure of the CDS/ADC standard document format, we added an option to search against the lead author's last name.
Year Published (e.g., 1993): This option allows the year of publication to be searched either by itself or in any combination with the lead author's last name and/or a text search of the entire document.
To help users easily refine their search terms, the search results page includes the search form with the terms as entered. If your search query results in zero matches, try again with a less specific search. One quick way to do this is to switch to the "Find Items with at Least One Search Word" option. If your search still does not turn up the data you want, try different terms, use your browser's "find" command on the holdings list , or ask for assistance by e-mail to webmaster@adc.astro.umd.edu.