Target Status Checks


With the start of the first Extended Mission, the Guaranteed Time Observation (GTO) Programme’s Reserved Target List (RTL) contains only up to 50 targets. All other targets are generally open for Guest Observer (GO) proposals.

Proposers must:

  • check the status of all your proposed targets via the PHT2 interface's Target and Programme Information webpage and its Target Checker. The tool indicates whether a target is on the RTL, part of an existing programme but unreserved (i.e., open for GO proposals), or not part of any existing programme (i.e., open for GO proposals). 
  • consult the Mission Archive for past observations on this target, and verify that new observations yield sufficient scientific merit.

Concatenate screenprints of the Target Checker and Mission Archive results for all your proposed targets into a single PDF, and upload this file in the submission step.

Note that if you query by target name, SIMBAD is used to retrieve its coordinates. Please always double-check the target coordinates, as not all target names (e.g., TESS Objects of Interest) are correctly resolved.


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.