- Focus the telescope using MIRA: if needed
- Slew to target and while slewing
- Configure MOSFIRE to image the alignment slitmask
Start Spectroscopic Observations .
- Click on "Bright Long" tab of the SAT.
- Click on "Acquire Image" to image the object.
- Click on "Move to Center" to center the object on the slit.
- Click on "Acquire Image" to check centering.
- Iterate acquisition and centering until star is center
on the box.
Nominal slit center is at 1042.83, 1051
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:
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:
- Highlight the target in the MAGIQ target list using the
middle mouse button, and ask the OA to slew to the new
- Ask to OA to run MIRA in the neighborhood
of your target.
- If you plan to observe the field for two hours (or more),
you may ask the OA to run MIRA one hour west of your target
- MIRA is always run using the J band filter.
In this step, we center the star within the small imaging window
centered on the longslit.
- While slewing, configure the spectrograph to image the
longslit alignment mask:
- Configure the CSU with the alignment longslit
- Click the Pre Config Filter button on the SAT
Bright Long tab to set filter and grating to
- When the OA tells you that your target is on MOSFIRE, check
the following information on FACSUM to verify that your
position is correct:
- Target name and coordinates
- Position angle (skypa)
- Pointing origin (should be SLIT)
- Confirm that MOSFIRE is configured for imaging:
- A longslit alignment mask has been setup and executed
on the CSU.
- A default instrument configuration is set on the
Options tab and will override the current
configuration if the selections are not set to
(with the exception of the filter, which will be
NB1061 regardless of what you select).
- Click Acquire image button. The software will
- Reconfigure the spectrograph as needed to image the
mask (ideally, you did this already while slewing to
the target to save time).
- Acquire an image of the target.
- Read, analyze, and display image.
- Mark measured object position with red cross.
- Mark slit center position with blue X.
- Review object centroid
- If the automatic fit was not correct, then click on the
correct center. The software should re-mark the object
centroids with a new red cross.
- Send telescope moves
- Click the Move to Center button to offset the
telescope and center the slit on the object.
- Return to Acquire Image step above and iterate
until the star is centered on the slit.
- Please note that if seeing is variable, it may not be
possible to center within better than a few pixels.
- Reconfigure the instrument for spectroscopy:
- Configure the CSU for spectroscopy.
- Set obsmode (grating and filter).
- Set the exposure parameters.
- Load an image from the data directory using Actions ->
Load Longslit Image.