This section describes important changes which took place during Periods 109, as well as changes expected to take place during Periods 110 and 111.

Distributed Peer Review:

Starting from Period 110, ESO employs Distributed Peer Review (DPR) for approximately half of the submitted proposals. In this paradigm, first introduced by Merrifield & Saari (2009), all PIs of proposals qualifying for DPR accept to review a number of proposals (N) submitted by their peers during the same cycle. Correspondingly, they accept that their proposals are reviewed by N peers who submitted proposals in the same cycle. More details and background information on DPR at ESO can be found in Patat et al. (2019). Users should familiarise themselves with the DPR rules and guidelines.
In Period 111, N = 10, and the criteria describing the proposals which qualify for DPR are as follows:

1. All proposals requesting a total time (including overheads) less than 16 hours are assigned to DPR. This time threshold is set to have an approximate 50/50 distribution between DPR and panels, and it is based on the time request statistics compiled in recent cycles.
2. Exceptions to this general rule are proposals including at least one ToO run, and DDT proposals.
3. All other proposals submitted during a regular cycle will be reviewed in the classical way by the OPC and the panels.
   

In Period 111, the review channel (DPR vs. panels) is assigned at the time of proposal submission, based on the above rules. The PI (or delegated PI; dPI) is informed about the assigned review process and prompted to formally accept the conditions at the time of submission. At this stage the PI/dPI can delegate the reviewer’s role to one of the co-Is listed in the proposal. The delegation can also occur when the list of co-Is is specified.

By submitting a proposal qualifying for DPR, the PI/dPI commits to follow the DPR rules (see DPR rules and guidelines).

New scientific keywords:

Since Period 110, a new set of scientific keywords replaces the OPC categories. While preparing their proposals in p1, users must select at least two keywords, and at most five keywords (ten keywords for Large Programmes), except that proposals for Calibration Programmes do not require any keywords. The keywords must be selected in decreasing order of relevance (i.e., the first selected keyword is the most relevant).

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 111. 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 112.

Instruments and Facilities

• NIRPS is currently still under commissioning and is not yet fully characterised, but will be offered as of Period 111. NIRPS
   is a near-infrared (971nm-1854nmm), high-resolution (up to R = 84 000), cross-dispersed (70 orders) fibre-fed spectrograph optimised for stability and designed for the detection and characterisation of exo-planets around late-type stars. It can be used simultaneously with HARPS to collect spectra from 380nm to 1854nm (with a gap from 689nm to 971nm) in a single acquisition. Its ultimate goal is to reach a long-term stability of ~1 m/s, but for the first period a more conservative value of 3 m/s is adopted. A Laser Frequency Comb for wavelength calibrations is expected to improve further the stability from period 112 onwards.
  
• HARPS can be operated simultaneously with NIRPS starting from period 111.
  

• The Visitor (Cassegrain) focus of the 3.6-m telescope is not offered during Period 112 due to the operation of NIRPS. The possibility of offering this visitor focus will be re-evaluated in the future.
• The Visitor focus of the NTT continues to be available during P112.
• The installation and commissioning of SoXS - the Son of X-Shooter - are expected to start in Period 112. As a consequence, SoFI has been decommissioned, and EFOSC2 is expected to be decommissioned during Period 112.
  
• The multi-object spectroscopic (MOS) mode of EFOSC2 has been decommissioned in Period 111.

• ULTRACAM:
  
  • ULTRACAM is a high-speed imaging photometer designed to study faint astronomical objects at high temporal resolutions. ULTRACAM employs two dichroic beamsplitters and three frame-transfer CCD cameras to provide optical imaging with a field-of-view of 60 and at frame rates of up to 300 Hz simultaneously in the u'g'r', u'g'i' or u'g'z' bands.
    
  • This PI instrument is offered to the ESO community for up to 5% of the observing time at the NTT in Period 109. Large Programmes will not be accepted.
    
  • Operation of this PI instrument requires the presence of the instrument team, so ULTRACAM programmes will preferentially be scheduled contiguously on periods of several nights. For questions on the instrument and observation strategies, users shall contact the instrument PI, Prof. Vik Dhillon (vik.dhillon[AT]sheffield.ac.uk), at least two weeks prior to submitting their proposal.
  • The ULTRACAM consortium is committed to support the PIs and observers from the ESO community that have been awarded telescope time with ULTRACAM. The ULTRACAM team will support the execution of the observations and the subsequent data reduction to allow the scientic exploitation of the data obtained with ULTRACAM.
  • Proposers must check that their planned observations do not duplicate any protected targets specified for ULTRACAM in the Period 112 GTO target protection webpages.