This summer, the WEAVE rotator was delivered by IDOM
to the William Herschel Telescope (WHT).
At the WHT, the rotator was mounted on a 'telescope simulator',
i.e. a rig allowing it to be positioned at any elevation angle, for a
campaign of tests. The main aim of the tests was to verify the
functionality and performance of the rotator before integrating
it with the rest of WEAVE.
The new rotator will be mounted at the WHT's prime focus, and will deliver a non-rotating field to the ~1000 optical fibers positioned over the focal plane (diameter 410 mm, corresponding to a 2-degree field of view).
The residual field rotation after a one hour exposure will be less than 5 arcsec (with closed-loop guiding), i.e. less than 0.1 arcsec on-sky at the edge of the field of view. The rotator includes a cable wrap via which the optical fibres are routed through the telescope structure down to the WEAVE spectrograph in its enclosure at the Nasmyth focus.