Recommissioning of UT4 with the Deformable Secondary Mirror

Published: 17 Jan 2017
UT4 and the 4 lasers of the AOF

From October to December 2016, Unit Telescope 4 (UT4) was shut down to install the new Deformable Secondary Mirror (DSM), as part of the Adaptive Optics Faciity (AOF) project. The joint planning by the AOF Project and Paranal teams allowed a very efficient re-commissioning of the telescope, and tests were also successfully performed on some of the AOF sub-systems.

The UT4 and AOF teams now have the pleasure to inform ESO users that since 19 December 2016, 5 days ahead of schedule, UT4 is back to regular operations using the new DSM in non-adaptive mode. The performance and behaviour of the unit telescope were assessed and are within the expected range. The full instrument park of UT4 has also been tested; HAWK-I, MUSE and SINFONI are performing as with the original secondary and have fully resumed science operations. The VLTI instruments have also been re-commissionned with UT4 and no problem has been reported. Regular science operations on the VLTI with the UTs will resume shortly.

The commissioning of the adaptive optics (AO) modules (GRAAL, GALACSI) and the DSM in AO mode will start during the first half of 2017. Additional information will be provided as the integration and the commissioning activities progress.