Overview

The expected Paranal Instrumentation and Facilities to be offered in Period of the call and changes foreseen for the following two periods are presented at the overview page.

Instruments and facilities

• MOONS - the Multi-Object Optical and Near-infrared Spectrograph – commissioning on UT1 Nasmyth A is planned to start in August 2026. Science Verification is preliminary planned for January 2027, pending successful commissioning. The instrument is foreseen to be available in P118 through the Fast Track Channel, or in a late P117 FTC at the earliest.
• The VLT Visitor Focus at UT1 is not available.
• FORS-Up, the FORS Upgrade project is an upgrade of FORS1. FORS2 will stay in nominal operation until the FORSup upgrade is available. First commissioning of FORS1 without the MXU is planned to occur in P117. During the second commissioning of FORS1, planned for approximately second quarter of 2027 (early P118) the Multi-Object Spectroscopy Unit (MXU) and Polarisation mode will not be available. The full operational capability of FORS-Up, encompassing all current modes, is expected to be achieved during P118.
• SPHERE: A new observation mode is foreseen that enables simultaneous observations with IRDIS’ polarimetric mode (DPI) and the IFS. In addition, it is planned to automatically offset the derotator angle during IRDIS-DPI observations in field-tracking mode to optimize the polarimetric efficiency of the observations.
• MUSE: The seeing-enhanced MUSE narrow field mode (NFM) is planned to be offered in the coming period. This new mode uses a visible wavefront sensor, which will have 70% sky coverage at Galactic Pole and deliver image quality of 0.15"-0.3".
• ERIS - the ability to perform blind offset acquisitions for AO guide stars with RP <18 mag and BP >19 mag (Gaia magnitudes) by using an offset star with BP < 19 mag within 2′ is being implemented and will hopefully be offered in a future period. If successful, this will increase sky coverage of the LGS mode, especially at high galactic latitudes.
• 4MOST: The 4-metre Multi-Object Spectroscopic Telescope (4MOST) instrument’s PAE on the VISTA telescope is expected in Q1 2025. The VISTA telescope will be upgraded to facilitate the installation of 4MOST. Operations are expected to start in Q1 2026 at the earliest.

VLTI

• After the last commissionings of ASGARD modules, updated information on the offered modes will be found on the ASGARD website.
• A project to make raw GRAVITY fringe tracker (FT) data available to GRA4MAT mode users is currently under development. This will provide science-quality FT data, and remove the need for dedicated low resolution GRAVITY observations for the same target. It is expected to have this capability available by the beginning of period 118. Users requiring such data are recommended to apply for GRAVITY for time being.
• PIONIER may be decomissioned at the end of period 118.
• Large Programmes are not offered for VLTI-UT in P118, due to ongoing Large Programme commitments.