P3.17 Orient the coronagraphs

• Phase : 3
• Status : Draft
• Category : Nighttime testing (functionality and operability) (C5) + Nighttime calibration (C6)
• Recurrence : before every observing target (CI, LSS), starting from commissioning.
• Duration : 4 hours

Description

• Adjust the orientation of the coronagraphic masks with respect to the true orientation of the M2 spider by rotating the SHARK-NIR derotator.

Prerequisites

• Atmospheric conditions: should be able to see bright stars in the sky (preferably close to zenith?).
• Authorize SHARK-NIR on the SX side.
• Suitable bright enough star close to zenith to have negligible effects from flexures (including the possibility of performing AO).

Procedure

• Pointing to a star, the first coronagraph is inserted in the path. The bearing is rotated, maximizing the contrast achieved on the SCICAM. (use the pupil lens to see the pupil's alignment, maybe)?
• This operation is repeated for all the coronagraphs.

Templates

Success criteria

• All the coronagraphs are aligned to the true orientation of the M2 spider by maximizing the contrast at SCICAM.
• Note down the contrast achieved for all the coronagraphs, including the atmospheric conditions and the brightness of the on-axis star.

Notes

LBTO support

• AO support

Date performed and by whom