revised 05/08/07

Auxport imaging facilities at WHT.
TEK2 is the CCD offered, 0.11 arcsec per pixel, UBVRI filters. Telescope focus 97.92 in R, or about 0.1mm higher than ISIS (5/8/07)
Using instrument AUX will report a rotator position 90 degrees offset with respect to ISIS. However, GSS does NOT take this into account even when specifying AUX as station. Therefore, for guiding there are two options: If using INSTRUMENT ISIS while observing with AUX, it generally best to use an angle of 45 degrees (or -45, 135, 225, etc) in order to align the CCD with the cardinal directions. With Rot Sky 0, INSTR ISIS, the orientations with TEK2 will be:

      |        |
North |  AUX   |
      |  TEK2  |
      |  Gen 3 |

Working with AG2

AG2 is a fast-readout frame-transfer science CCD, that works the same way as an autoguider, Gen III udas, to allow ultra-fast photometry.
It has a number of operating peculiarities that need to be recorded:
  • Observing out of focus to prevent saturation of bright stars, even with <10s exposures. Typically Telescope Focus 99.0mm.
  • This requires Autoguider focus to be adjusted near its limit: 6500 for the above telescope focus (17-Sep-2007)
  • They require very precise and reproducible positioning on the detector. This means recording Autoguider Probe positions and pixel x,y for each target.
  • Since they follow an object for many hours, you have to make sure it will not be interrupted by rotator limits. Wind off rotator if necessary.
  • Watch out for dome stopping tracking if object is in the south.