Effective 19 August 2026, XMM-Newton observing proposals are solicited in response to the Twenty-sixth Announcement of Opportunity, AO-26.
The XMM-Newton Project has joint programs with the VLT, NRAO (i.e., VLA, GBT, VLBA), HST, JWST, HESS and MAGIC, as well as with other X-ray missions: Chandra, IXPE (New!), NuSTAR, Swift and XRISM. The XMM-Newton Project may additionally award observation time to these facilities via the current AO.
A letter from ESA’s Director of Science, inviting you to participate in the Twenty-sixth Call for Proposals, is available in electronic form [PDF].
The deadline for XMM-Newton AO-26 proposal submission is Friday 9 October 2026, at 12 noon UTC (8a Eastern, 5a Pacific).
