Foreseen Changes regarding La Silla and Paranal Instrumentation and Facilities

La Silla

  • A NIR Laser Frequency Comb for NIRPS has been delivered in 2023 and is currently under test. It  should be available on best effort basis for P114.
  • EFOSC2 will be decommissioned once Son of X-shooter (SoXS) enters regular operation on the NTT. It is expected to be decommissioned during Period 114.



The expected Paranal Instrumentation and Facilities to be offered in Period 113 and changes foreseen for Periods 114 and 115 are presented at the overview page.


  • Further improvements of the new Phase 1 system (p1) will take place in the following Periods.

Instruments and facilities

  • MOONS - the Multi-Object Optical and Near-infrared Spectrograph – is expected to be installed at the UT1 Nasmyth A focus during the second or third quarter of 2024.
  • The VLT Visitor Focus at UT1 will be available, but the installation of the field corrector lens for MOONS may pose restrictions.
  • FORS1,  the upgraded FORS instrument, is expected to be installed and see first commissioning in P116. FORS2 will thus be decommissioned in P116, and  first commissioning of FORS1 without the MXU is planned to occur in P116. Subsequent semesters will see the retrofit of the MXU to FORS1 together with subsequent commissioning.
  • FORS2: The FORS2 Absolute Photometry (FAP) will be decomissioned by early 2024, which means that users from P113 onwards can no longer rely on the zeropoints and extinction coefficients to photometrically calibrate their data. The pipeline is currently being prepared to calibrate imaging data observed with the standard BVRI filters using Gaia synthetic photometry. About 10%-15% of the FORS2 imaging may not have suitable Gaia stars in the FoV, because there are either none or only saturated ones. ObsPrep will soon allow users to verify the availability of Gaia stars with synthetic photometry already during Phase1. If this is needed, the users are expected to provide their standard OBs together with the science observations.
  • UVES: In order to recover a progressive degradation in resolution in UVES blue arm camera, an intervention is foreseen, indicatively planned for Q4 2024, that should put UVES out of operation for a few weeks.
  • VISIR: Due to a very low demand, it is planned to decomission the instrument after P114, well in advance of the arrival of CUBES at Paranal.
  • ERIS - Pupil tracking for NIX imaging and IFS observations may be offered in subsequent semesters.
  • ESPRESSO - A maintenance of the LFC is scheduled for Oct/Nov. 2023 aimed at improving the LFC current performance. The LFC status and performance will be updated in the ESPRESSO news webpage and in the user manual.
  • GRAVITY+ Adaptive Optics (GPAO): More technical acitivies on GRAVITY+ AO will talke place in P115. The next and last major step will be the installation and commssioning of Laser Guide Star systems for VLTI-UTs during the middle of P116. It is foreseen to offer this new capability in P117.
  • We sucessfully tested a new standard AT medium configuration A0-B5-D0-G1 that improves observability, functionality and baseline-complementarity between configurations. It is planned to put it in operations from P115.
  • The VLTI Visiting Instrument Asgard is planned to arrive in 2025 on Paranal. After commissioning, access to observing time for the community will be orgnized by the consortium on a best effort basis.