Acquiring Objects on the nirspec Guider

Dim target acquisition (blind offsets from star brighter than 15th mag, position angle mode)

  1. Ask OA to slew to your offset star
  2. While slewing, give the OA the RA/Dec offsets to your science target
  3. Ask the OA to acquire the offset star on SCAM
  4. Once the offset star is centered in the slit, ask the OA to switch to the annular guider. The OA will change guide cameras and try to find a suitable guide star.
  5. Once guiding on the annular guider, verify that the offset star remained in the middle of the slit. Use the Slit-nod widget to correct if necessary.
  6. Ask the OA to mark the current position as base and then apply the offset.
  7. Observe

For very dim science objects requiring 15-20 minute integrations, many observers prefer to nod the offset star along the slit manually instead of relying on ABBA scripts. In this case, the observing procedure will be:

  1. Once guiding, move the offset star along the slit to the first nod position.
  2. Ask the OA to mark base
  3. Take a short spectrum for trace purposes
  4. Offset to the science target
  5. Take a single long spectrum on the science object
  6. Undo the offsets (return to base)
  7. Nod the offset star along the slit to the second nod position.
  8. Ask the OA to mark base
  9. Take a short spectrum for trace purposes
  10. Offset to the science target
  11. Take a single long spectrum on the science object


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Last modified: Mon Jun 5 13:43:20 HST