The generic URL used in ASU follows the generic rules of the HTTP protocol (RFC 1945):
http://root_URL?arg1&arg2&...where the ampersand &) separates the arguments when there is more than a single argument. The HTTP protocol also specifies that any special character (blank, quotes, and + * < > & # ) exsiting in an argument should be encoded by a percent sign (%) followed by its ascii hexadecimal representation. The blank must therefore be replaced by %20, the + sign by %2b, etc.
The root URL to get results from VizieR is
In the root URL, the host name (vizier.cds.unistra.fr) may be replaced by one of the mirrors: vizier.ast.cam.ac.uk, vizier.cfa.harvard.edu, vizier.hia.nrc.ca, vizier.nao.ac.jp, vizier.iucaa.ernet.in, vizier.inasan.ru, vizier.bao.ac.cn, vizier.ukirt.jach.hawaii.edu.
Following the question mark (?), the ASU arguments are written in the general form name=value The following conventions about name are used:
Specifying a Choice of Catalogues: there are several ways of designating catalogues; the fastest is to use the catalog identification assigned in VizieR like -source=I/239/hip_main for the main Hipparcos catalog.
-source= | catalog(s) to query
(Several catalogs may be specified if separated by
a comma or a blank). Well-known catalog abbreviations may be used – the full list of abbreviations known in VizieR can be listed. | ||||||||
-words= | names or words of title of catalog. The words are and'ed, i.e. only the catalogues characterized by all the words are selected. | ||||||||
-kw= | keyword in any of the 3 lists by Wavelength,
Mission, or Astronomy. If several keywords are given on the line, they are or'ed; but if several lines with -kw=value exist, their content is and'ed. | ||||||||
-ucd= | designation of UCD The catalogues having one or more columns matching the specified UCD(s) are selected; the * may be used as a wild character, e.g. PHOT_*_B represents a blue photometry which can be in a lot of different photometric systems. Several -ucd=value can be used to select catalogues having simulteously the properties specified by the UCDs; in other terms, similalry to -kw, UCDs specified on the same line are or'ed, while the different lines are and'ed. | ||||||||
-pos | restricts to tables containing celestial positions | ||||||||
-phot | restricts to tables containing well-defined photometry | ||||||||
-nosurvey | restricts the choice to catalogues outside the ``survey'' list of catalogues. | ||||||||
-obsolete | asks to include the obsoleted versions of catalogues in the set. | ||||||||
-corr= | correlation for a fine-grain selection of tables:
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Target Center: the specification of a target requires a center – a position in the sky – and a geometry around the center. Only a circle/annulus, and a rectangular box, are available.
-c= | defines the center of the target There are many possibilities of specifying the center – by object name, position in sexagesimal or decimal degrees. For equatorial positions, remember that a sign must exist before the declination, and that no decimal point in the RA part implies a sexagesimal position (i.e. 15 +12 means 15h+12°, but 15.+12 means 15°+12°, or 1h+12°. |
-c.eq= | defines the equinox of the position given in
the -c argument. Note that this parameter
is not useful when the target is specified by a name. Typical examples are -c.eq=B1950 or -c.eq=Gal The default is -c.eq=J2000 |
-c.rm= | defines the radius of the target in arcminutes. Two numbers may be specified: in the case, the target is an annulus. |
-c.rd= | defines the radius of the target in degrees. |
-c.rs= | defines the radius of the target in arcsec. |
-c.bm= | defines a rectangular box of horizontal/vertical dimensions in arcmin, as e.g. -c.bm=8x6 |
-c.bd= | defines a rectangular box in degrees |
-c.bs= | defines a rectangular box in arcsec. |
-box= | defines a rectangular box using IAU-conventions, e.g.
J0000-00 for a box
in J2000 coordinates containing the positions
having their RA between 0h0m and 0h1m
and their declination between 0° and –1°
This convention is valid also with other coordinate systems:
Bhhmm...±dd... (B1950 position),
Glon...±lat... (galactic position),
S... (supergalactic)
and E (ecliptic). Finally a box may also be represented by a qbox value, the systems of cells used to access by positions (described briefly in the qbox man page) |
Output Contents: the contents and order of the result can be specified by the following arguments:
-meta | No actual query is performed, only the tables involved in the query are described. This is useful to get an idea of which catalogues exist which share e.g. a keyword. | ||||||||||||||||||||||||||||||||||||||
-meta.all | similar to -meta, but all metadata (details of columns) are listed. | ||||||||||||||||||||||||||||||||||||||
-meta.max= | specifies the maximal number of catalogs to be listed (the default is 500) | ||||||||||||||||||||||||||||||||||||||
-out= | specifies the result columns to list in the output;
-out= is normally followed by a list of column names
(separated by blanks)
to be displayed. The list may contain, in addition to standard column names:
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-out.all | Display all columns (i.e. -out.all is equivalent to -out=**) | ||||||||||||||||||||||||||||||||||||||
-out.add= | List of columns to add to the standard set, e.g. -out.add=_r lists the distance to the target | ||||||||||||||||||||||||||||||||||||||
-out.max= | Maximal number of rows to retrieve (default is 50) | ||||||||||||||||||||||||||||||||||||||
-out.meta= | Some options on the descriptions of the columns,
as a set of characters referring to the possible additional details;
the list may be preceded by + or - for addition or
removal of the following elements:
The default is huD; to get for instance the 2 UCDs, add -out.meta=+2 | ||||||||||||||||||||||||||||||||||||||
-out.form= | Some options on the output:
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-sort= | Sort order, e.g. -sort=_r to sort by increasing distance to the target. A minus sign before the column name (e.g. -sort=-_r) indicates a decreasing order. | ||||||||||||||||||||||||||||||||||||||
-oc.form | form of the computed position, as -oc.form=d for decimal degrees, or-oc.form=s for sexagesimal representations. An optional M (Main) can be added to specify that the UCD qualification main main is added to the computed position (by default this main qualification is attached to the original position) |
Joining tables: Two or more tables can be combined or joined into a single table; some details and examples can be found in the join documentation. The following argments are specific to joins:
-joincol | specifies the column used in the join (the name must be shared among the tables involved). |
-outjoin | specifies the table.column of the referent column in the case of outer joins. |
Issuing several queries: Independant queries can be issued in a single request, using a -go separator. More control can be specified in the case of votable output: