9. Once the star is well positioned on the science detector, select a guide star.
* Open the guide star software (the icon of a star with a long tail).* Enter coordinates of the target field in the guide star software and click "GET IMAGE". A window should appear with a 10x10 arcmin DSS map. In order to save time, this step could have been done earlier whilst telescope was slewing.* Click on a bright brightish star '''outside''' of the green circle in the DSS image. **NOTE: this chart is centered on the coordinates. If you have substantially adjusted the position of the target to be away from the center of the acquisition frame, there will be the same offset in whatever guide star is selected.
* Under "XY Slides Control," click "GoTo GS". The star should appear in the acquisition image. If not, try a different star.
* Under “Pointer" click "Guide Star" , then click on the chosen guide star in the acquisition camera FOV. This will put a dark blue box (guide point) centered of the star.
* Press '''GUIDE''' on the '''Exposures & Guiding''' box to start guiding.
** NOTE: if the star is near a hot pixel, that could cause trouble with guiding. Click "Move XY" and click on the star: this will center it (just moving the XY stages, and not effecting the science target).