Discretionary programme (DP)

This webpage provides prospective proposers with all information required to prepare and submit proposals to the CHEOPS Discretionary Programme (DP). The DP runs throughout the year and may have up to 25% of the total science observing time of the Guest Observer (GO) Programme, with the remaining at least 75% dedicated to the annual Announcements of Opportunity (AOs).



DP proposals have to be submitted at the latest 3-4 weeks before the date of the first possible observation. We highly recommend already alerting us via email to cheops-support at cosmos.esa.int before you start preparing your DP proposal, as this will allow our team to prepare for the incoming submission.



An eligibile DP proposal for early-career scientists (i.e., before or within 2 years from PhD award) must meet the following criteria:

  1. Contain a single target of high scientific interest
  2. Contain a target/event that is observable by the date by the end of the running AO observing cycle and that is not on the Reserved Target List

An eligibile DP proposal for mid- and late-career scientists (i.e., more than 2 years after PhD award) must meet the following criteria:

  1. Contain a single target of high scientific interest
  2. Demonstrate that the target was either (a) discovered, or (b) declared to be of high scientific interest since the closure of the previous AO
  3. Contain a target/event that is observable by the date by the end of the running AO observing cycle and that is not on the Reserved Target List


Important Notes

Prospective observers must take note of the following points:

  1. Read the Policies and Procedures document carefully before starting any proposal preparation, as it is the definitive document for the DP. It contains details of CHEOPS' science programme, available time for the community, observing strategy and constraints, and required contents of observing proposals. It also lists information about the tools and documents available to support observers in their proposal preparation and submission. Also thoroughly consult the Observers Manual and all relevant documentation on this website.
  2. All proposal material and file names must be fully anonymous. Failure to comply with this rule will lead to automatic rejection on formal grounds.
  3. Register to the CHEOPS GO Programme immediately if you do not already have a user account. Waiting with this step until the deadline might cause you to miss the opportunity.
  4. Consult the Target Checker, Archival Data, Visibility Checkers, and Exposure Time Calculator. Make sure your target is eligible by checking the publicly available list of all of CHEOPS' targets (reserved and unreserved ones) and the GTO programme information. Ensure that your observations will contribute something new by checking the CHEOPS Mission Archive to see what data CHEOPS has already gathered. Verify that your target is observanle with the visibility maps, visbility checkers, and the Scheduling Feasibility Checker. Finally, make sure you can achieve the desired signal-to-noise by using the exposure time calculator.
  5. Submit your proposal via the Proposal Handling Tool for Phase 1 (PHT1). You can now simply follow the streamlined proposal submission process step-by-step.

Please also note that:

  • Updates related to the DP and its material will be published at the bottom of this webpage.
  • Note the special case of Alpha Cen (including Alpha Cen A and Alpha Cen B): The system is currently on the RTL but due to its high proper motion and orbital motion, the Target Checker will not resolve its RTL coordinates if querying by name. Alpha Cen’s RTL coordinates are given in the RTL csv file, please use these for any Target Checker queries for this system.
  • We list detailed examples helping you with making your proposals dual-anonymous on the FAQ pages. Please read these carefully and do not hesitate to contact us with any questions.
  • The CHEOPS team will do everything we can to observe and complete awarded programmes if possible. However, it is important to appreciate that an award of observing time does not guarantee that the observations can be conducted, even if a programme is considered to be high priority science. Due to the nature of the science that CHEOPS addresses, time pressure can be high, unforeseen events can occur, and some observations might not be feasible to schedule.
  • CHEOPS is a small mission, with a correspondingly small team to support the GO Programme. Never leave proposal preparation to the very last moment, as it may take a couple of days to answer your questions.


Key Documentation



No updates yet. Happy proposing!


Are You Ready?

Have you read all the above information and key documents carefully and are ready to start the submission process? Then go to the Proposal Submission webpage or click the button below to follow the step-by-step guide.



Questions about CHEOPS or the GO Programme? Please email cheops-support at cosmos.esa.int and we will be happy to help!
This website was last updated on 26 February 2024.