Accessing catalogues

Most of the CURSA applications prompt you to enter the name of at least one catalogue. You should reply with the name of the file containing the catalogue. The file name of a CURSA catalogue comprises the `catalogue name' followed by the `file type', for example:

perseus.FIT

where `perseus' is the catalogue name and `.FIT' the file type. The catalogue name is restricted to contain only: upper or lower case alphabetic characters (a-z, A-Z), numeric characters (0-9) and the underscore character (`_'). The file name may optionally be preceded by a directory specification.

CURSA uses the `file type' of the file name to determine the format of the catalogue (FITS table, TST or STL) and therefore the file name must end in the appropriate file type. The file types for the three catalogue formats are:

FITS table:	.FIT .fit .FITS .fits .GSC .gsc
TST:	.TAB .tab
STL:	.TXT .txt

The .GSC and .gsc file types for FITS tables are provided in order to allow regions of the HST Guide Star Catalog to be accessed easily. Other FITS tables obtained from an external source, such as those mentioned in Section , may have a different file type. They must be renamed (with the Unix command mv) to have a recognised file type before they can be accessed with CURSA.

A few additional details which are specific to the individual catalogue formats are described below. The peculiarities and limitations of the three catalogue formats are described in full in Appendix .