AO-4: Approved Programmes

Announced on 14 July 2023

The 4th Announcement of Opportunity (AO-4) for the CHEOPS Guest Observers (GO) Programme opened on 4 April 2023 and closed on 26 May 2023. The opportunity marks the start of the first extended mission and covers observing time in the period from 25 September 2023 until 30 September 2024. Notably, the available GO share of the science observing time was recently increased from 20% (in the Nominal Mission) to 30% (in the first Extended Mission).

A total of 29 proposals were received in reply to AO-4, requesting 1811.1 orbits (with each orbit circa 99 minutes in duration). The requests represented 120% of the available science observing time foreseen in the AO-4 observing cycle (circa 1505.5 orbits).

The CHEOPS Time Allocation Committee (TAC) met on 19 - 20 June 2023. Based on the TAC's recommendations, the Director of Science has awarded CHEOPS observing time to the proposals listed in the table below. In the end, 24 proposals were awarded observing time totaling 1472.1 orbits. Of these, 19 proposals were on exoplanet science, 3 on stellar science, and 2 on other science/goals. The TAC-recommended allocation of observing time represents up to 98% of the available GO science observing time foreseen in the AO-4 observing cycle (circa 1505.5 orbits). Of these, 3 pairs of programmes have duplicate targets, for which the TAC recommends sharing observing time. We will be in contact with the teams and liaise the next steps.

Succesful proposals will be implemented as GO programmes. Targets that are part of these GO programmes can generally not be included in other observing programmes unless in specific cases. All programmes have been assigned a priority from 1 (high) to 3 (low), in some cases at the level of individual targets. This priority is taken into account by the automated planning tool used in the weekly/biweekly planning, and is a strong indicator of the likelihood that observations will be scheduled. Observers are reminded that the award of observing time provides no guarantee that the observations can be executed, and that generally more observing timeis awarded than can be physically scheduled to minimise idle time.

Principal Investigators (PIs) of proposals that have been awarded time will be contacted by email, and are required to complete and submit observation requests at their earliest convenience. Guidelines on how to prepare observation requests will be posted on this webpage shortly. The TAC feedback will be provided to all PIs of proposals.

A fraction of up to 25% of the GO Programme time will remain available to the community to apply for time via the Discretionary Programme (DP), which is foreseen to continue running throughout the mission lifetime. This is in line with a possible over-allocation of up to 133% to facilitate the efficient scheduling of time critical observations. 

*/**/*** These 3 pairs of programmes marked with asterixis have duplicate targets, for which the TAC recommends sharing observing time. We will be in contact with the teams and liaise the next steps.