Third Announcement of Opportunity

In consideration of ESA’s contribution to XRISM, not less than 8% of the total Guest Observing Time, or an equivalent return as mutually agreed, shall be allocated to ESA. The ESA Director of Science is expected to issue an invitation to submit proposals in mid-January 2026. Cycle 3 will commence on or about 1 June 2026, and last for a period of approximately 12 months until on or about 31 May 2027.

The instructions to submit proposals are summarized in the Announcement of Opportunity for the XRISM GO program and the The XRISM Proposers’ Observatory Guide.

Proposal submission deadline was 27 February 2026.

Results from Cycle-3 can be found at official JAXA XRISM website. Congratulations to all the successful proposers!

Additional information

• Further information about XRISM can be found in this XRISM Quick Reference guide.
• Information for studies of feasibility can be found under XRISM Proposal Tools
• Response files for Cycle 2 assuming the Resolve Gate Valve Closed
• Documentation and resources are available here: https://heasarc.gsfc.nasa.gov/docs/xrism/proposals/
• The terms under which personal data are collected with the purpose of processing the proposals can be found under this: Privacy Notice
• For any questions, the European community is encouraged to make use of the European XRISM User Support Portal.