Paranal: Foreseen Changes regarding Instrumentation and Facilities


The expected Paranal Instrumentation and Facilities to be offered in Period 112 and changes foreseen for Periods 113 and 114 are presented at the overview page.


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

UT 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. It is planned that ObsPrep will in the future allow users to verify the availability of Gaia stars with synthetic photometry already during Phase1, so that they can request additional standard star observations if needed (In P113 all FORS2 IMG observations will be accompanied with a STD field, whereby from P114 users will have to request this in Phase 1).
  • 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): Following the implementation of GPAO (natural guide star modes only), VLTI-UT (MACAO and CIAO) operation should be restarted as early as October 2024, in a consortium-assisted period where the probability of technical problems is non-negligible. Regular operations should resume in December 2024, to be confirmed. The Laser Guide Star modes of GPAO installation is currently planned for January 2026 to March 2026 (P116B). The current plan is to offer it to the community from P117.
  • In order to improve observability, functionality and baseline-complementarity between configurations, we plan to modify the definition of the standard AT medium configuration from K0-G2-D0-J3 (old medium) to A0-B5-D0-G1 (new medium) in a future period.