This section describes important changes which took place during Period 103 and 104, as well as changes expected to take place during Period 105.

p1: A new tool for proposal preparation and submission:

A new tool for the preparation and submission of observing proposals is deployed in Period 105. This represents the first part of a broader re-haul of the ESO Phase 1 system (p1) that also entails a significant modernisation of the Observing Programmes Committee, refereeing process, and related tools. The new p1 system is web-based, resembles the recent p2 tool. Users are encouraged to get familiarised with the new system using the p1demo tool well before the proposal deadline.

Large Programs:

Starting in Period 104, Large Programmes are only offered in even Periods, i.e., Periods with proposal submission deadline in March/April.

Introduction of turbulence categories:

With the advent of instruments using new adaptive optics (AO) modes, new turbulence parameters need to be taken into account in order to properly schedule observations and ensure that their science goals are achieved. These parameters include the coherence time and the fraction of turbulence taking place in the atmospheric ground layer, in addition to the seeing. Such a change was initiated for the SPHERE instrument in Period 103.

In Period 105, the new turbulence constraints are standardised to the turbulence conditions required by all instruments and modes, whether they are seeing-limited or AO-assisted. Users are encouraged to read the general description of these changes for Phase 1 and Phase 2 on the Observing Conditions webpage, as well as instrument User Manuals for specifics per instrument. The Exposure Time Calculators have been updated to reflect these changes.

In addition, interested readers should refer to the article by Martinez et al. 2010 (The ESO Messenger 141, 5) "On the Difference between Seeing and Image Quality" which describes the meaning of these two quantities.

Instruments and Facilities

• NIRPS:  the Front End Adaptive Optics and the Back End of the Near Infra-Red Planet  Searcher are expected  to  be  commissioned at  the  3.6-m telescope in the fourth quarter of 2019 and the 2nd/3rd quarter of 2020, respectively. The installation of NIRPS is not expected to affect the operations of HARPS in Period 105.
• SoFI and EFOSC2:  Monitoring Programmes with SOFI and EFOSC2 are not offered in Period 105, as the installation and commissioning of SoXS - the Son of X-Shooter - is expected to start during the first quarter of 2021.
  
• 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 105. 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]sheeld.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 105 GTO target protection webpages.