Catalog Assistant Help

The Phase I Tool includes a catalog assistant tool which has been designed to help search for wave front sensor guide stars.

  1. Select a server and search algorithm.
    Guide star catalog servers are available at CADC, ESO and STScI (others may become available soon). Generally you will get the best performance by selecting the server that is geographically closest. Note that only the GSC-I catalog may be available, which contains stars down to about 15 mag. Work on GSC-II is well advanced but this deeper catalog may not be available.
    The only algorithm available at this time will attempt to find guide stars for the two Peripheral Wavefront Sensors (see the telescope section of the external web site for details).
  2. Advance to the next page using the arrow in the bottom right corner of the assistant.
  3. Select all or specific science targets from the target list to have guide stars found. Individual targets may be selected/deselected using the "included?" checkbox.
  4. Activate the search by clicking on the magnifying glass icon. The green LED will flash whilst the search is in progress. You can stop the search by clicking on the traffic light icon. The status for each target will change from pending to complete when finished.
    Upon completion the search results for each target are listed at the bottom of the page. The star name, coordinates, magnitude and other information are shown for each star.
    Generally the algorithm will select the brightest two stars available in the PWFS patrol field. You can override the algorithm, and view all potential guide stars from the chosen catalog that are in the patrol field, by selecting the target and using the "override?" checkbox. You may then choose alternative, or additional, stars.
  5. Complete the guide star search by clicking on the finish button. The selected guide stars will be added to each observation in the program information tree.