20 December 2023
The Chandra X-Ray Center (CXC) is pleased to announce the release of the Chandra Cycle 26 Call for Proposals (CfP). The Call for Proposals, Proposers' Observatory Guide (POG), proposal planning software, and general information are posted on the "Proposer" web page at the CXC website. Proposals are due Thursday 14 March 2024 at 6p Eastern (3p Pacific).
What's New in Cycle 26:
Statement concerning the High Resolution Camera (HRC) operation: Presently, the use of HRC is limited to observing for 14.5 ks at a time with a minimum 30 ks buffer between subsequent HRC observations. HRC observations over 14.5 ks will be split accordingly. Time-constrained HRC observations for which all splits must be completed within a short observing window will incur a high resource cost and are subject to further technical review. Uninterrupted HRC observations longer than 14.5 ks are infeasible and such requests will incur an infinite resource cost. There are also restrictions for HRC observations before and after Chandra enters radiation zones. Limits on HRC usage are subject to change over the observing cycle.
Update to the expected minimum response time for Target of Opportunity (TOO) observations: The expected minimum response time for a TOO is now 48 hours. Previously, the expected minimum response time was 24 hours. Proposers may continue to request the full range of 0-5 day response times for very fast triggers.
Updates to the Joint Program Requirements: In Cycle 25, a joint program opportunity became available with the James Webb Space Telescope (JWST). 150 hours of JWST observing time are available for this opportunity. A total of 300 ksec of Chandra observing time is available for award as part of the annual JWST Call for Proposals. For Cycle 26 onward, a proposer requesting JWST time will be required to submit additional information to STScI no later than two weeks after the Chandra deadline. This information is necessary for STScI to assess the feasibility of the requested JWST observations and is provided in Section 5.2 (of the CfP). Proposers will be notified after the deadline.