Cycle 3 Director's Discretionary (DD) Time Proposals

Directors' Discretionary Time proposals are discussed in this article, including the circumstances under which they are used and how to submit them.

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Time-critical DDT proposals

Time-critical Director's Discretionary Time proposals might be appropriate for:

  1. Follow-up of newly-discovered unexpected transient phenomena, or when developments since the last proposal cycle make a time-critical observation necessary;
  2. The timely follow-up of new discoveries that will provide a critical link in the understanding of the phenomena. 

Requests to reserve target of opportunity targets that have not yet been discovered are not appropriate for Director's Discretionary Proposals.

Director's Discretionary Proposals are small, typically <15 hours in size. Proposals requesting significantly more than 15 hours are better suited for the standard observing cycle and its TAC review process.

Joint JWST-HST DD proposals are permitted. Proposals should be submitted to the observatory with the larger time request. Joint DD proposals with other facilities are not permitted. Similarly, preparation for future cycle programs is generally an insufficient justification for DD time.

Please note: All scheduling requirements must be specified, including timing requirements that would require disruptive (< 14 days) or ultra-disruptive (< 3 days) turnaround times for activation. The limitations on each of these are described in JWST Target of Opportunity ObservationsThe activation timescale begins when the notification of acceptance is sent to the PI. Most proposals will be subject to external peer review after they are submitted; when considering whether a proposal is disruptive or non-disruptive, PIs should thus factor in a minimum of 5 days for this review process to complete, and longer for proposals submitted late in the week.

NIRSpec MOS programs must be finalized at least 4 weeks before execution. Consequently, NIRSpec MOS is not available for disruptive (< 14 day) DD programs.

The Special Requirements section must include an explicit statement on when the observations have to be executed.

Proposals that imply a time requirement, e.g., “as soon as possible,” but do not specify a disruptive or ultra-disruptive activation time, will be returned. There are a limited number of ultra-disruptive activations available in Cycle 2, so please justify accordingly.

Once a proposal is approved, any subsequent requests for changes may jeopardize the execution of the program and will be accepted only under highly exceptional circumstances.

Time-critical DD observations should not generally be requested if any of the following is true:

  • The observations could plausibly have been proposed in the most recent regular proposal cycle, possibly as a target of opportunity proposal;
  • The observations were proposed in a recent regular proposal cycle, and were rejected;
  • The proposed observations could wait until the next proposal cycle with no significant reduction in the expected scientific return.

The use of Director's Discretionary Time, as opposed to time awarded during the regular observing cycle by the standard TAC review process, MUST be well justified. In particular, preparation for future observing cycles is typically insufficient justification for Director's Discretionary Time.

Subject to availability of funds from NASA, STScI will provide financial support for U.S. PIs and Co-Is of approved DD programs.

More information about past and present opportunities is available at JWST Director's Discretionary Time



DDT proposal preparation

DD proposals may be submitted and will be reviewed in an anonymous format. The review process is similar to that used in the JWST Cycle 3 Anonymous Proposal Reviews, except the review of the team expertise will be done internally by the Science Policies Group. Please fill out the "Team Expertise and Background" section of the proposal, but it will not be shared with the reviewers.

Proposers should use the Astronomer's Proposal Tool (APT) to submit their DD programs and make sure to check the DD checkbox. To download and install APT, go to the APT webpage. For help on using APT to prepare and submit a JWST program, please refer to the Getting Started with JWST Proposing article. You will be providing all necessary information (including all necessary observing parameters) via the APT tool and you will attach your scientific justification and observation description as a PDF attachment to your submission, as is typical for JWST GO proposals. More detailed information is included below.

Templates for the PDF attachment of the "Scientific Justification" can be found on the current cycle's preparation of the PDF attachment article. Page limitations should follow the Page Limits for the PDF Attachment for proposals of the same-sized proposal category, as shown on the JWST Guidelines and Checklist for Proposal Preparation - Cycle 3 page. Make sure to use the template appropriate for DD proposals.

Upon completion of your DD submission, your program will be transferred to the STScI for processing by our DD team. If you run into problems submitting a DD request, contact the JWST Helpdesk for investigation and resolution.

Please refer to the section on Director's Discretionary Time proposals in JWST Proposal Categories - Cycle 3 for policies regarding DDT proposals.

Proposals for DD time must be sufficiently detailed for adequate evaluation. The required level of detail is the same as that required for proposals submitted for the regular observing cycles, as described in the current James Webb Space Telescope Call for Proposals for Cycle 3. 

Among other things:

  • both the proposed observations and the use of DD time must be explicitly justified;
  • there must be an adequate description of how the proposed observations relate to the current state of knowledge;
  • the proposed observations must be described in sufficient detail to allow technical evaluation;
  • the APT file must be telescope-ready.




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