Frequently Asked Questions (FAQ)
For the Discretionary programme (DP)

Below is a collection of Frequently Asked Questions (FAQs) and their answers, relating to the preparation and submission of proposals for CHEOPS' Discretionary Programme (DP). This webpage will be updated regularly to answer questions that come up relating specifically to the programme, including submission of proposals. If you do not find an answer to the question you have, please review the documentation provided on the DP webpage. If you still cannot find the answer, then please send an email to Please note that it may take a few days for questions to be answered, and to be put up onto this webpage.


Q1) What ideas and targets are eligible?

Full details, including constraints on the number and type of targets that can be proposed, are provided in the Policies and Procedures document which is available at this link.


Q2) What is the turn-around time?

We recomend at least 3-4 weeks. All DP proposals received in the Phase-1 system are vetted by the ESA CHEOPS Project Scientist (PS) for their eligibility and technical feasibility, and then forwarded to the Time Allocation Committee (TAC) for their review. Upon approval, the PS will be in touch with the proposers to prepare their Phase-2 input. Once all input has been crosschecked by the PS and Science Operations Centre (SOC), it can be submitted. An activity plan, or observing schedule, covering 1 week of observations is typically created by the SOC on Mondays, discussed by the Project Science Office (PSO) on Tuesdays, uplinked to the spacecraft on Wednesdays, and start to be executed on Saturdays. Generation of the activity plan itself typically takes a couple of days and starts already on Monday - it should be possible to include new observations requests (ORs) for consideration that have been completed AND have been submitted by the midnight GMT on the day before the planning starts (Sunday).


Q3) To what level of precision do I need to provide target coordinates?

Please see our dedicate webpage explaining the Coordinates format to avoid delays and disappointment. The coordinates for targets for any CHEOPS observation need to be provided in degrees (J2000, icrs) with precision of a minimum of 6 (RA) and 5 (Dec) decimal places. The correct coordinates need to be provided as part of the PHT1 input - directly into the proposal handling tool that you use to submit yiour proposal - as this information is sent directly to the cScience Operations Centre on approval of a proposal, and cannot be updated when preparing observation requests. 



Importantly, remember what the goal of dual-anonymous peer-review is. The goal is to shift the focus of the review onto the science case - and away from the PI and their team (and their names, genders, etc.). The goal is not to make it completely impossible to guess who the team is.

For example, proposals should say "A recent study showed that the period of this planet is 42.0 days (Adams et al., 1978)" instead of saying "We showed that the period of this planet is 42.0 days (Adams et al., 1978)".

To this end, it is crucial to not claim nor indicate ownership of past work, work in preparation, or proprietary data sets. If referencing such points, proposers must indicate this as "private communication" without including the names of the respective individuals or teams. It can help to use third person neutral wording for this. In most cases, it can be as simple as saying "Previous CHEOPS programmes on this target have ruled out several period aliases, leaving only the options outline here (private communication)".

Sometimes the proposers may have access to unique facilities or skills. Stating this is not against any principles of the dual-anonymous peer review as long as the identities of the team are not explicitly revealed. For example, proposals should say something like "These observations will be performed simultaneously with JWST, for which the project has been awarded 365 days of telescope time." or "The target's stellar activity will be monitored with 1-metre class ground-based facilities before/after the event."

Note that the Management Plan section of the proposal is not anonymised. This section will be removed from all proposals before the science evaluation by the TAC. Thus, it gives an excellent opportunity to add specific details to back up certain claims in the main part of the proposal. For example: "The relevant JWST programme has the number 123456 (link)." or "The proposing team leads the Tiny-ELT consortium of 1-metre class telescopes."

If in doubt, please do not hesitate nor overthing - simply send an email and examples to cheops-support at, and we will be happy to help.

Questions about CHEOPS or the GO Programme? Please email cheops-support at and we will be happy to help!
This website was last updated on 12 March 2024.