Paranal: Important recent changes regarding instrumentation and facilities

This section describes important changes which took place during Periods 107 and 108, as well as changes expected to take place during Period 109.

General

Proposal anonymisation:

Period 108 marked the full deployment of the Dual-Anonymous Peer Review (DAPR) for proposals submitted to this Call. Applicants must formulate the scientific rationales of their proposals following the anonymisation rules and examples described in this link, which also gives a detailed description of the DAPR paradigm. While Period 106 was used as a dry run, both to make the community aware of the upcoming implementation of DAPR and to test its practical, procedural and policy aspects, from Period 108 proposal anonymisation is mandatory. Failure to abide by the DAPR rules may be penalised.

The fields Background and Expertise and Data Product Delivery Plan (in the case of Large Programmes) are the only fields of the proposal in which information on the proposing team can be disclosed. These fields will not be included in the material distributed to the referees during the proposal review phase and will only be accessible to them after the ranking phase is completed.

Large Programs:

Large Programmes, those that require 100 hours or more, are not accepted for Period 109. Large Programmes can only be submitted in even Periods, i.e., Periods with the proposal submission deadline in March/April. A number of instrument restrictions for Large or Monitoring Programs apply. We refer the reader to Sect. 4.4 in the Call for Proposals Period 109.

Rapid Response Mode (RRM) activation policy:

The RRM policy changed starting in Period 105: on-going observations on any VLT instrument can be interrupted by an RRM triggered on that specific UT, even if the trigger requires a change of focus, unless the relevant programme is specifically protected against an RRM trigger (in case of strictly time-critical programmes). The change is currently being tested, and is expected to be fully operational by Period 109. More information on the Rapid Response Mode can be found on the Phase 2 page.

UT instruments and facilities

UT1 - Antu

  • KMOS:
    • KMOS, is expected to be fully operational in P109 with an intervention to fix the failing arms scheduled for September/October 2021.

UT2 - Kueyen

  • VISIR:
    • The instrument will has been mounted on UT2 in August 2021.

UT3 - Melipal

  • SPHERE: 
    • For the star center observations (obs. Type=C), the WAFFLE pattern amplitude in all modes is calculated automatically and should be left as “AUTO” by default.
  • CRIRES:
    • Polarimetry as well as off-axis guiding have been successfully commissioned for the upgraded CRIRES instrument. In Period 109, CRIRES will be offered to the community with all modes.
  • XSHOOTER:
    • Starting in P108, the convention for acquisition with blind offsets from a reference star has been changed to follow the standard used by VLT instruments. Please be aware of this when preparing your observations. Carry-over OBs with blind offsets and p2fc finding charts have to be updated accordingly.

UT4 - Yepun

  • MUSE:
    • The extension of the GALACSI NFM tip-tilt limiting J-band magnitude has been commissioned. Details are available on the news page of MUSE.
    • Since Period 106, the AO supported MUSE Narrow Field Mode (NFM-AO) is offered for Monitoring and Large Programmes.
    • Target of Opportunity proposals are accepted for MUSE in all its modes.

Incoherent combined focus

  • ESPRESSO:
    • The 4-UT mode is offered in Visitor Mode only. Observations will be scheduled in groups of consecutive nights. Users must request a total time that is an integer multiple of half-nights (corresponding to 4 hours in Period 106), with a minimum duration for each individual observing slot of one half-night.
    • Proposals requesting 4-UT mode must in particular justify its use compared to the 1-UT mode.
    • Monitoring, Large Proposals, and DDT are accepted for 1-UT mode only.
    • Since P107 ESPRESSO is offered with a 4x2SLOW binning and readout scheme in high-resolution mode. This configuration is suited for science that targets very low S/N while using only one UT.

Visitor focus

  • The UT1 Nasmyth A focus is available for Visitor Instruments, but the installation of the field corrector lens for MOONS may impose limitations.
  • Potential users of a visitor focus are requested to consult the VLT Visitor Instruments page.

VLTI instruments and facilities

General:

  • For new users to VLTI needing assistance to prepare their VLTI proposals, the community supported VLTI Expertise Centres - disseminated throughout Europe - can offer in-depth support. They also offer support for advanced data reduction and interpretation.
  • VLTI+UT operations will not be available for 6 weeks at the beginning of P108 due to the first phase of the recoating of the four UT coudé trains.
  • Monitoring and Large Programme proposals on the VLTI-UTs and VLTI-ATs are accepted for both GRAVITY and PIONIER without restrictions, and for MATISSE for all modes except the HIGH+ spectral setting and the GRA4MAT mode.

VLTI-ATs:

  • In Period 109, ESO will continue a scheme to optimise operations for aperture synthesis with the VLTI. This scheme only applies to service mode proposals using ATs with PIONIER, GRAVITY and MATISSE. The reader is referred to the Period 108 VLTI manual (valid for Period 109) for further details.

Instruments

  • Two VLTI visitor foci are available in Period 109. Potential users are requested to consult the VLTI Visitor Instrument page.
  • GRAVITY is offered on all AT configurations as well as on all four UTs with the visible (MACAO) and infrared (CIAO, off-axis only) adaptive optics system in Service and Visitor modes.
    • The on-axis mode of the IR wavefront sensor CIAO cannot be offered for the time being due to critical problems that were identified during its commissioning.
    • ESO invites proposals with the goal of performing astrometric measurements, a capability of GRAVITY which is still under development (see, e.g., GRAVITY Collaboration 2017 A&A 602, A94). Proposers who wish to use the astrometric capability and contribute to its development are invited to consult the GRAVITY webpage and contact the astrometric team at least two weeks before the proposal deadline.
  • MATISSE is offered in Period 109 on the UTs (supported by the visible MACAO AO system) and on the short, medium and large AT configurations in Service and Visitor modes.
    • MATISSE is available with the GRA4MAT mode with ATs fully, and only without chopping for UTs.
    • The instrument offers the choice of various spectral resolving powers covering either L and/or M-band (depending on the resolving power) and N-band. The HIGH+ mode is only available with the GRA4MAT mode.
    • Monitoring and Large programmes are offered in all settings in Period 109, except for the new HIGH+ spectral setting. Additionally, Large or Monitoring Programmes requesting the GRA4MAT mode will not be accepted.
  • PIONIER is offered on all ATs configuration and UTs + MACAO in both service and visitor mode. The limiting magnitudes of PIONIER have been updated following the improvements thanks to the installation of NAOMI. The execution times have been adapted accordingly. See the overview or overheads pages.
 

Survey telescopes and instruments

VISTA: VIRCAM

  • Due to a reported delay in the delivery of 4MOST, the end of VIRCAM operations has been further postponed, and VIRCAM is now offered for Period 109. A large fraction of VIRCAM time in P109 is devoted to allow the completion of the remaining ongoing ESO Public Surveys, as well as Large Programmes. However, a significant amount of VIRCAM observing time is available for normal programmes within the full range of atmospheric conditions. Particularly encouraged are open time proposals requesting any weather conditions (THIN and turbulence category 85% or 100%), and avoiding RA ranges  RA=0-2h, 4h, 7h-10h, as those are allocated with remaining public survey and large programme OBs.
  • Monitoring Programmes are not accepted for VIRCAM in Period 109.