The CATalog Server, or CAT, is designed to help the operator select a star in a certain region of the sky for sending to the TCS as a guide, WFS, or Science target. Given a Right Ascension/Declination or Azimuth/Elevation input from the user, it will display all the stars in a certain radius from the given point in a visual and a tabular format. It is important to remember that the search is based on RA-DEC and not AZ-EL and the conversion from AZ-EL to RA-DEC has some uncertainties. CAT does an approximate conversion which is good enough for the search purposes.

The above image is the default layout for CAT. It is separated into five components:

• User View - where the input for the search is entered
• Target View - displays the information on the selected target and allows sending to the TCS
• Image View - displays the field of view and the objects within
• Table view - a tabular display of the objects which allows sorting
• Science Target View - displays the info on the current science target accepted by the TCS

There are currently three catalogs in the database:

• FK6 Bright Star Catalog
• Tycho
• UCAC4

More details on CAT can be found in the following pages: