Quick Review

  1. Focus the telescope using MIRA: if needed
  2. Slew to target and while slewing
  3. Fine Alignment:
  4. Start Spectroscopic Observations .

Nominal slit center is at 1042.83, 1051

Slitmask Alignment

This checklist describes the procedure for aligning a relatively bright object on a standard MOSFIRE Longslit using the Slitmask Alignment Tool (SAT). This process differs from the procedure for aligning a MOSFIRE slitmask with the SAT.

To launch the SAT:

Focus telescope

Re-focusing the telescope is recommended periodically during the night but is not required for each mask alignment. It is generally recommended to re-focus the telescope when the telescope elevation angle has changed by 30° or more.

To complete the focus:

  1. Highlight the target in the MAGIQ target list using the middle mouse button, and ask the OA to slew to the new highlighted target.
  2. Ask to OA to run MIRA in the neighborhood of your target.

Slew to Target

  1. While slewing, configure the spectrograph to image the longslit alignment mask:
  2. When the OA tells you that your target is on MOSFIRE, check the following information on FACSUM to verify that your position is correct:

Fine Alignment

In this step, we center the star within the small imaging window centered on the longslit.
  1. Confirm that MOSFIRE is configured for imaging:
  2. Click Acquire image button. The software will then:
  3. Review object centroid
  4. Send telescope moves


  1. Reconfigure the instrument for spectroscopy:
  2. Expose...phew!

Tips and Tricks