This page describes the additional (optional) flags that may apply to GO proposals; these flags include Calibration, Combined GO+AR, Future Cycles, Joint Observing, Pure Parallel, Target of Opportunity, and Treasury. Each flag has specific requirements that must be met.

There are additional (optional) "flags" that may apply to GO proposals of any size:

• Calibration proposals provide calibrations for non-standard instrumentation modes.
• Combined GO+Archival (AR) proposals are available when substantial effort (>10%) will be devoted analyzing JWST archival data and where new observations are still required to address a scientific goal.
• Proposers can request observing time in future cycles as a Future Cycles proposal when this is scientifically justified. The proposal's total time, and hence its size category, will be determined from the sum total of time for all cycles in the request.
• There are opportunities to apply for Joint Observing programs with other specific observatories to obtain multi-wavelength data.
• Pure Parallel proposals utilize instruments other than the primary instrument on observations from unrelated proposals (see also the Pure parallel observations section of JWST Proposal Types and Categories).
• Target of Opportunity (ToO) proposals are for observations of an event that may occur at an unknown time (see also JWST Target of Opportunity Observations).
• The category of Treasury proposals is designed to stimulate certain types of ambitious and innovative proposals. These typically have a significant legacy value by making high-level data products or software tools publicly available. Treasury programs may request any number of hours and hence may be any GO size category.

Each flag has additional requirements that must be satisfied.

Calibration

JWST is a complex observatory, with many possible instrument configurations. Calibrations and calibration software are maintained by STScI for the most important and most used configurations. However, STScI does not have the resources to calibrate fully all potential capabilities of all instruments. Additionally, the astronomical community has expressed interest in receiving support to perform calibrations for certain uncalibrated or poorly calibrated modes, or to develop specialized software for certain JWST calibrations. In recognition of this, STScI is encouraging users to submit Calibration Proposals, which aim to fill gaps in the calibration of JWST and its instruments.

Calibration proposals should not be linked to a specific science program, but should provide a calibration or calibration software that can be used by the community for existing or future programs. A specific science program that has special calibration requirements is not a Calibration proposal; such a proposal should be submitted as a normal GO proposal and the necessary calibration observations should be included in the science program.

Successful proposers will be required to deliver documentation, data products, and/or software to STScI to be made available to the community to support future observing programs or archival research. Funding is available to support Calibration GO proposals in the same manner as for normal science programs, with the following exception: Scientists affiliated with STScI are not eligible for any funding to support their role (as PI, Co-PI, or Co-I) in a Calibration proposal.

Investigators interested in submitting a Calibration GO proposal are encouraged to study the JWST User Documentation to determine the level at which STScI provides calibration and characterization. The data obtained for a Calibration GO proposal will nominally have no Exclusive Access Period, as is the case for regular calibration observations. Proposers may request an Exclusive Access Period (which must be explained in the "Special Requirements" section of the PDF attachment), but such a request will be subject to panel and TAC review and will only be granted in exceptional circumstances. 

The JWST GO hours request determines whether the proposal is Very Small, Small, Medium, or Large. 

Additional APT requirements

Investigators submitting Calibration GO proposals must select the "Calibration" flag on the APT Proposal Information form.

Additional PDF attachment requirements

Proposers should summarize the relevance and overall scientific utility of the calibration techniques and products described in their proposal. The "Scientific Justification" should describe what science will be enabled by the successful completion of the program, and how the currently supported core capabilities, their calibrations, and the existing data processing are insufficient to meet the requirements of this type of science. Calibration GO proposals must include both a "Description of Observations" and an "Analysis Plan" in the PDF attachment. The "Analysis Plan" should discuss what documentation, and data products, and/or software will be made available to STScI to support future observing programs. Proposers should explain how their programs complement ongoing calibration efforts by the STScI instrument groups. They must contact the relevant instrument groups to ensure that efforts are not duplicated, and if they are, justify why the duplications are necessary. Requests for a non-zero Exclusive Access Period must be justified in the "Special Requirements" section.

Calibration GO proposals should follow the page limit requirements as for regular GO proposals of the same size category.

How these proposals are reviewed

Calibration GO proposals are subject to the same review process as for regular GO proposals of the same size category.

Calibration GO proposals recommended by the TAC will be reviewed internally at STScI after the TAC Review Meeting to assess of the feasibility of the proposal, how the proposal complements/extends the existing calibration program, and the type of science impacted by the proposed calibrations.

Combined GO+AR

The Combined GO+AR option is for research programs where substantial effort (>10%) will be devoted to analyzing JWST archival data and where new observations are still required to address a scientific goal. In other words, programs that require funding for archival research alongside new observations should be submitted as a single proposal (rather than separate GO and AR proposal submissions). The Combined GO+AR category is applicable when the archival component comprises >10% of the total effort of the research program. Programs with a less significant archival component should be submitted as a regular GO program. In either case, the GO and archival science must be clearly described and justified.

Proposers should also be familiar with the requirements for AR proposals. They can select additional GO or AR flags as appropriate.

The GO time request determines if a Combined GO+AR proposal is Very Small, Small, Medium, or Large. Combined GO+AR proposals have the same default Exclusive Access Period and are subject to the same review process as for regular GO proposals of the same size category. 

Additional APT requirements

Investigators submitting Combined GO+AR Proposals must select the "GO-Archival" flag on the APT Proposal Information form.

Additional PDF attachment requirements

Combined GO+AR proposals must include a "Description of Observations" for the new data. Optionally, they may include an "Analysis Plan" for the archival data. Where the analysis of the archival data is distinct from that of the new data, an "Analysis Plan" may be appropriate. However, an "Analysis Plan" may not be needed if the new and archival data will be analyzed in the same way. Regardless, both the new observations and the archival data must be described in the proposal. 

Medium and Large Combined GO+AR proposals should follow the page limit requirements as for regular GO proposals of the same size category. Very Small and Small Combined GO+AR proposals are allowed an additional page compared to regular Very Small and Small GO proposals. Please consult JWST Preparing the Proposal PDF Attachment for details.

Future Cycles

GO proposals of any size may request JWST observing time in more than one cycle if a clear scientific case can be made. Future Cycles proposals must be limited to cases where long-baseline, multi-epoch observations are clearly required to achieve the scientific goals. Future Cycles proposals require a long time baseline, but not necessarily a large number of JWST hours, to achieve their science goals. Examples include astrometric observations or long-term monitoring of variable stars or active galactic nuclei. Proposers may request time in up to three cycles (i.e., 6, 7, and/or 8) in a regular Future Cycle proposal, or in up to five observing cycles (i.e., Cycles 6–10) under the Long-Term Monitoring (LTM) Initiative. 

Non-disruptive ToO observations are eligible to be Future Cycles proposals; Disruptive or Ultra-disruptive ToO observations may be requested in the first cycle of a Future Cycle proposal but cannot be requested in later cycles of a Future Cycle proposal. Proposers interested in ToO observations should be familiar with the differences between Future Cycles ToOs and Carry-over ToOs.

Future Cycles cannot be requested for Pure Parallel programs.

The sum of all hours requested in all cycles determines whether a Future Cycles proposal is Very Small, Small, Medium, or Large. Future Cycles proposals have the same default Exclusive Access Period and are subject to the same review process as regular GO proposals of the same size category. 

Approved Future Cycles proposals are not required to submit continuation proposals for subsequent cycles.

Additional APT requirements

Investigators submitting Future Cycles proposals must fill out the "Future Cycles" expandable menu on the APT Proposal Information form, with the cycle-by-cycle breakdown. If this field is not marked and filled out, the Future Cycles request might not be met, even if it is described in the proposal. Investigators participating in the LTM Initiative must select the "Long Term Monitoring" flag on the APT Proposal Information form. Once checked, observations for two future cycles beyond the default 3-cycle limit will be able to be requested (though not required).

The observations specified in APT should only be those corresponding to the current cycle. APT files for time awarded in future cycles will be requested at a later time.

Additional PDF attachment requirements

Future Cycles proposals should describe the entire requested program and provide a cycle-by-cycle breakdown of the number of hours requested in the "Description of Observations" section of the PDF Attachment. The review panels and TAC will only be able to award a limited amount of time in future cycles, so a detailed scientific justification for allocating time beyond Cycle 6 must be presented. Scheduling concerns are not a sufficient justification.

Future Cycles proposals should follow the same page limit requirements as regular GO proposals of the same size category. 

Joint Observing

STScI has reached agreements with several other observing facilities (ALMA, Chandra, HST, NASA Keck, NOIRLab, NRAO, TESS, XMM-Newton) to award time for joint programs in which JWST science is the prime science, but multi-wavelength observations from another ancillary observatory are critical for the science goals of the proposal. Joint proposals aim to remove double jeopardy in the review process (i.e., being subject to two independent review processes). Joint Observing programs with more than one Partner Observatory are allowed.

Joint Observing proposals should be submitted to only one facility:

• Joint JWST-ALMA, JWST-HST, and JWST-NRAO Observing Proposals should be submitted to the observatory that requires the larger charged time allocation (where 1 JWST hour of charged time is equivalent to 1 HST orbit).
• Joint JWST-Chandra and JWST-XMM-Newton Observing Proposals should be submitted to the facility that represents the prime science.
• Joint JWST-NASA Keck, JWST-NOIRLab, and JWST-TESS Observing Proposals should be submitted as a response to the JWST Call for Proposals. 

Proposers are responsible for fulfilling all necessary requirements requested by the Partner Observatories. This includes noting what information needs to be submitted, meeting the deadlines for submitting that information, and ensuring that contact details are up to date. 

Unless otherwise stated in the proposal, it is assumed that there is no requirement on the relative timing of the JWST and Partner Observatory observations. A request for contemporaneous or near-simultaneous observations can be made if scientifically justified and technically feasible, but there is no guarantee that these can/will be executed.

The only criterion above and beyond the usual review criteria is that both sets of data are required to meet the primary science goals.

Joint Observing programs can be Very Small, Small, Medium, or Large programs; proposers should determine the size category based on the JWST hours request. Joint Observing programs may be combined with other GO flags; however, proposers should note that:

• While ToOs are allowed, additional restrictions may be imposed by the appropriate mission depending on circumstances;
• Requests for observations in Future Cycles (including as part of the LTM special initiative) only apply to the JWST observations. The same is true for any ToO observations requesting carry-over status.

Joint Observing programs have the same default Exclusive Access Period and are subject to the same review process as regular GO proposals of the same size category. 

Additional APT requirements

Joint Observing programs are referred to as Multi-Observatory in APT.

Investigators submitting Joint Observing proposals must select the "Multi-Observatory" flag in the APT Proposal Information form and fill in the required "Multi-Observatory Information":

• JWST is primary if you are submitting the proposal in response to the JWST Call for Proposals. In this case, you are prompted to request time on one or more Partner Observatories in the "Coordinated Telescopes" section;
• JWST is secondary if you are applying for JWST time through the Partner Observatory Call for Proposals. You will need to submit an APT file for the JWST observations. In this case, you are prompted to identify the primary observatory and provide the primary proposal ID under "Multi-Observatory Information". Proposers should refer to Submission Process for Joint JWST Proposals where the Partner Observatory is Prime for additional details.

If this information does not appear in APT, the proposal may be disqualified or the joint program request might not be met, even if it is described in the PDF attachment. 

Additional PDF attachment requirements

Joint Observing programs should follow the same page limit requirements as regular GO proposals of the same size category.

Proposers should take care to include any partner-observatory specific justifications (detailed below) in the "Justify Coordinated Observations with Other Facilities" section of the PDF attachment.

If you have plans for conducting coordinated observations with other facilities that are not being applied as JWST Joint Observing programs but which affect the JWST scheduling, please describe them in the "Justify Coordinated Observations with Other Facilities" section of the PDF file to be uploaded into APT, including how those observations will affect the scheduling. If you have plans for supporting observations with other facilities that are not being applied for as JWST Joint Observing program and do not affect JWST scheduling, then do not describe them here. If they improve your science case, then describe them in the "Scientific Justification" section of the proposal.

Specific information and requirements by Partner Observatory

Joint JWST-ALMA Observing Proposals

By agreement with Joint ALMA Observatory (JAO), the JWST Telescope Allocation Committee (TAC) will award up to 115 hours of ALMA time on each of the ALMA arrays (12-m, 7-m, and Total Power) to highly ranked proposals that require both JWST and ALMA observations. Similarly, the JAO will be able to award up to 115 hours of JWST time to highly rated proposals awarded ALMA time in its TAC process. The only criterion above and beyond the usual review criteria is that the project must be fundamentally of a multi-wavelength nature, and that both sets of data are required to meet the science goals. ALMA time will only be awarded in conjunction with new JWST observations (and should not be proposed for in conjunction with an AR proposal).

Unless otherwise stated in the proposal, it is assumed that there is no requirement on the relative timing of the JWST and ALMA observations. A request for contemporaneous or near-simultaneous observations can be made if scientifically justified and technically feasible but there is no guarantee that these can/will be executed.

Proposals for combined JWST and ALMA observations should be submitted to the observatory with the larger time request (not to both observatories). STScI reserves the right to disallow JWST observations that duplicate those approved via any joint program unless the duplications are justified in the original proposals. 

Joint proposals requesting ALMA time: 

• Must comply with the ALMA Users' Policies and Call for Proposals guidelines (https://almascience.org/proposing/learn-more).
• Will be allowed to request array configurations offered between the time the project will enter the ALMA queue (i.e., upon project preparation subsequent to proposal approval, as indicated in the JWST Preparing the Proposal PDF Attachment document) until the end of the ongoing ALMA Cycle, as well as those offered in the upcoming ALMA Cycle.
• Cannot request ALMA time for VLBI or phased array observing modes. 
• Cannot be Large Programs, that is request > 50 hours on the 12-m array or > 150 hours on the 7-m array (see the ALMA Proposer's Guide for a definition of a Large Program). 

Establishing the technical feasibility of the ALMA observations is the responsibility of the PI, who should review the ALMA Proposer’s Guide or consult with the JAO. ALMA will not do a preliminary technical assessment (i.e., before the JWST TAC). Projects that during the preparation of the observations are deemed not to match with the initial technical justification, including requested time, may be deemed unfeasible. For proposals that are approved by the JWST TAC, detailed feasibility checks will be conducted by the JAO. The JAO reserves the right to reject any previously JWST-approved observation that proves infeasible, impossible to schedule, and/or dangerous. Any ALMA observations that prove infeasible or impossible could jeopardize the overall science program and may cause revocation of the corresponding JWST observations. Duplicate ALMA observations may also be rejected by the JAO.

Upon acceptance of a Joint Proposal by STScI, PIs will be required to submit their programs to the JAO using the ALMA Observing Tool. The JAO will prepare Scheduling Blocks and perform a final detailed technical assessment. Programs with significant technical issues may be rejected at the discretion of the JAO. Once the Scheduling Blocks have been prepared, projects will immediately enter the ALMA observing queue, unless requesting observing capabilities only offered in the upcoming Cycle. In that case the project will enter the queue at the corresponding Cycle start date. Approved programs may remain in the ALMA queue for a period of up to two years.

Additional APT requirements

In the "Coordinated Telescopes" section of APT, proposers must fill in the necessary ALMA hours request.

Additional PDF attachment requirements

In the "Justify Coordinated Observations with Other Facilities" section, proposers must provide a full and comprehensive technical justification for the ALMA portion of their program, including:

• the choice of array (12-m, 7-m, or Total Power) and the array configuration (if the 12-m Array is requested),
• the number of sources and the mapping area (Single Pointing, Multiple Pointings, Rectangular Mosaic of given area),
• the requested time including overheads calculated using the Observing Tool (OT). If the requested time was not calculated using the OT, then the proposal should include an explanation for how the time was estimated,
• the requested Band(s) and Correlator Configurations,
• the representative sensitivity for reference array (i.e. 12-m, or 7-m for ACA stand-alone projects) and aggregated bandwidth used for sensitivity calculation,
• the highest spectral and imaging signal-to-noise ratios expected in your sample,
• any time constraints, including simultaneous or coordinated observations involving multiple observatories,
• whether full-polarization is required. If so, then provide the coordinates of any source with a declination north of +30deg and the expected source linear/circular polarization fraction.
• any other requirement that would be included in the OT (extra text boxes in the technical justification section).

During proposal preparation, proposers must use the ALMA Observing Tool (OT) to validate their program. In addition, they must provide a list of OT messages. This must include any blue message reported by OT at the top of the Technical Justification section and any warning/error message when validating the project. (Exclude obvious errors, like missing title/abstract/scientific justification, which are not required for the purpose of Technical Justification.)

If the observing capabilities requested are not supported by the Observing Tool, then proposers must use other tools provided by ALMA (https://almascience.org/tools) and include a detailed explanation of the assumptions made and the process by which observing time was estimated. 

Joint JWST-Chandra Observing Proposals

By agreement with the Chandra X-ray Center (CXC), the JWST TAC will be able to award up to 300 kiloseconds of Chandra observing time. Similarly the CXC will be able to award up to 150 hours of JWST time to highly rated proposals awarded Chandra time in its TAC process. The only criterion above and beyond the usual review criteria is that the project must be fundamentally of a multi-wavelength nature, and that both sets of data are required to meet the science goals.  Chandra time will only be awarded in conjunction with new JWST observations (and should not be proposed for in conjunction with an AR proposal). Proposers should take special care in justifying both the scientific and technical reasons for requesting time on both missions.

Unless otherwise stated in the proposal, it is assumed that there is no requirement on the relative timing of the JWST and Chandra observations. A request for contemporaneous or near-simultaneous observations can be made if scientifically justified and technically feasible but there is no guarantee that these can/will be executed.

Time-constrained Chandra observations awarded in the JWST review are limited by the finite amount of Resource Cost (RC) available to the JWST review. In addition, only one rapid ToO (less than 20 days turn-around time) can be awarded. The minimum expected response time for any ToO is 48 hours after triggering a Chandra observation. JWST Cycle 6 proposers should keep their Chandra requests within these limits.

Proposals for combined JWST and Chandra observations should be submitted to the observatory that represents the prime science (not to both observatories). STScI reserves the right to disallow JWST observations that duplicate those approved via any joint program unless the duplications are justified in the original proposals. While there is multi-wavelength expertise in the review panels for both observatories, typically the JWST panels will be stronger in IR science and the Chandra panels in X-ray science.

Establishing the technical feasibility of the Chandra observations is the responsibility of the PI, who should review the Chandra documentation or consult with the CXC. For proposals that are approved by JWST, the CXC will perform detailed feasibility checks in Chandra Cycle 29. The CXC reserves the right to reject any previously JWST-approved observation that proves infeasible, impossible to schedule, and/or dangerous to the Chandra instruments. Any Chandra observations that prove infeasible or impossible could jeopardize the overall science program and may cause revocation of the corresponding JWST observations. Duplicate Chandra observations may also be rejected by the CXC.

For the health and safety of the Chandra spacecraft, the amount of Chandra exposure time available for High Ecliptic Latitude (HEL) targets with |b_Ecliptic| > 55 deg is limited. Refer to section on HEL targets in the Chandra Call for Proposals for detailed information. If you request joint time on Chandra, please avoid long exposures on such targets if at all possible. You must note explicitly the requested amount of Chandra HEL time in the body of your science justification.

Monitoring particle background requires that at least one front illuminated chip is turned on for all Advanced CCD Imaging Spectrometer (ACIS) observations. Therefore, S3-only observations are no longer permitted. Please refer to the Chandra proposers' observatory guide for details.

The High Resolution Camera (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. 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. Please refer to the Chandra proposers' observatory guide for details.

Similarly, constraints that may limit the number of days your targets are observable can be difficult to accommodate within Chandra scheduling. Chandra uses Resource Cost (RC) to represent this difficulty; please refer to the Section on Resource Cost in the Chandra Call for Proposals for more detailed information. Only a fixed total number of RC points, as calculated by Chandra’s RC calculator, may be awarded by Chandra's joint partner observatories. Every proposal requesting joint Chandra time should explicitly list the RC total of their requested Chandra time in the body of the science justification, except for ToOs where the sky position is unknown. The nominal resource cost is 1.6 RC per 1 ks of Chandra observing time, however it can vary broadly based on observing constraints, sky position and exposure times. Please refer to the section on Resource Cost in the Chandra Call for Proposals for details. Additionally, the proposers must verify that Chandra will be able to acquire suitable star fields for a given target using the Star Checker tool.

Full specification of approved observations will be requested during the Chandra Cycle 29 period. For proposals that are approved, the Chandra team will perform detailed feasibility checks. Chandra reserves the right to reject any approved observation that is in conflict with safety or mission assurance priorities or schedule constraints, or is otherwise deemed to be infeasible.

Additional APT requirements

In the "Coordinated Telescopes" section of APT, proposers must fill in the necessary Chandra kiloseconds request.

Proposers must specify in the "Team Expertise" section whether they were awarded Chandra time in a previous Chandra cycle for similar or related observations.

Additional PDF attachment requirements

In the "Justify Coordinated Observations with Other Facilities" section, proposers must provide a full and comprehensive technical justification for the Chandra portion of their program. This justification must include:

• the choice of instrument (and grating, if used),

• the requested exposure time and justification for that exposure time,

• target count rate(s) and assumptions made in its determination,

• the exposure mode and chip selection (ACIS) or instrument configuration (HRC),

• information on whether the observations are time-critical; indicate whether observations must be coordinated in a way that affects the scheduling of either Chandra or JWST observations,

• information about nearby bright sources that may lie in the field of view,
• a demonstration that telemetry limits will not be violated,
• a description of how pile-up effects will be minimized (ACIS only).

Technical documentation about Chandra is available from the Chandra X-ray Center (CXC) webpage, which also provides access to the Chandra Help Desk. The primary document is the Proposer’s Observatory Guide, available from the Chandra Proposal Information webpage. Proposers should review this document or consult with the Chandra Guest Observer Facility. Establishing the technical feasibility of the proposal is the responsibility of the PI.

Joint JWST-HST Observing Programs

By agreement with the HST Project, the JWST TAC may nominally award 300 orbits of HST observing time. Similarly, the HST TAC may nominally award 150 hours of JWST time. The time will be awarded only for highly ranked proposals that require use of both observatories and shall not apply to Archival or Theory Proposals. The only criterion above and beyond the usual review criteria is that both sets of data of the same target(s) are required to meet the primary science goals. Proposers should take special care in justifying both the scientific and technical reasons for requesting observing time on both missions. (All Joint JWST Observing Programs are GO - no Joint JWST-HST AR proposals are offered at this time.) 

HST recently transitioned to Reduced Gyro Mode. The main impact for users is that the field of regard is reduced to approximately 40%–45% of the sky, comparable with JWST. Further information can be found in the Reduced Gyro Mode Tips and Resources.

Unless otherwise stated in the proposal, it is assumed that there is no requirement on the relative timing of the JWST and HST observations. A request for contemporaneous or near-simultaneous observations can be made if scientifically justified and technically feasible but there is no guarantee that these can/will be executed.

If a science project requires observations with both HST and JWST, then a single proposal may be submitted to request time on both observatories to the JWST Announcement of Opportunity, so that it is unnecessary to submit proposals to two separate reviews. The proposal should be submitted to the observatory that requires the larger time allocation time including overheads (where 1 JWST hour is equivalent to 1 HST orbit). Since STScI operates both HST and JWST, the amount of time for JWST-HST Joint Proposals could be revised upwards if the demand is high. 

Target of Opportunity observations are allowed. Target of Opportunity (ToO) proposals must state explicitly whether the HST observations require a non-disruptive or a disruptive ToO (the latter for observations within 21 days of notification). No more than one (1) disruptive HST ToO of the joint program will be performed per HST Cycle. Furthermore, Ultra-rapid HST ToO requests (reaction time 2 days or less) will not be accepted for this program; proposals asking for Ultra-rapid HST ToO observations must be submitted in response to the HST Call for Proposals, with HST as the primary observatory. It is mandatory that the PI informs both observatories immediately if the trigger criterion is fulfilled. For this solicitation, no HST time will be allocated without the need for JWST time on the same target to complete the proposed investigation.

Joint JWST-HST proposals are permitted to be multi-cycle in nature for both JWST and HST observations, either as a Future Cycles or LTM program, with some caveats. Programs may only request Future Cycle observations with HST if the program also requests Future Cycle observations with JWST. The total time requested on each observatory determines the overall size of the program and should be used to determine where to submit the program (1 hour on JWST is equivalent to 1 orbit with HST). Additionally, the overall Future Cycle baseline of the JWST observations may not exceed the Future Cycle baseline of the HST observations. Proposers should enter the total amount of HST time needed in APT, and describe the breakdown by Cycle in the PDF attachment. Failure to describe the breakdown correctly may result in disqualification.

Establishing the technical feasibility of the HST observations is the responsibility of the PI, who should review the HST Call for Proposals, Instrument Handbooks, and/or contact the HST Helpdesk. The HST Helpdesk offers new features, to search our documentation and to send your question directly to the appropriate team of experts. For proposals that are approved by JWST, STScI will perform detailed feasibility checks. STScI reserves the right to reject any previously JWST-approved observation that proves infeasible, impossible to schedule, and/or dangerous to the HST instruments. Any HST observations that prove infeasible or impossible could jeopardize the overall science program and may cause revocation of the corresponding JWST observations. Duplicate HST observations may also be rejected by the STScI.

Successful proposers will be contacted to provide an HST Phase I and Phase II for their program.

Exclusive Access Periods for JWST data and HST data will be set independently following the policies for each observatory according to proposal size and type (for example, if the JWST observations are "large" and thus non-proprietary, but the HST observations are small, the HST data could be proprietary). If a user has a Joint JWST-HST or HST-JWST program and they request a waived or reduced Exclusive Access Period, it will apply to both missions. 

Additional APT requirements

In the "Coordinated Telescopes" section of APT, proposers must fill in the necessary HST orbits request.

Additional PDF attachment requirements

In the "Justify Coordinated Observations with Other Facilities" section, proposers must provide a full and comprehensive technical justification for the HST portion of their program, including

• the choice of HST instrument and mode,
• the requested exposure time, justification for the exposure time, target count rate(s), and assumptions made in their determination,
• health and safety checks if needed,
• information on whether the observations are time-critical; indicate whether the observations must be coordinated in a way that affects the scheduling (of either HST or JWST observations) and if they are feasible with respect to scheduling, 
• any other Special Requirements, if necessary.

Technical documentation about HST is available online.

Joint JWST-NASA Keck Observing Proposals

By agreement with NASA HQ, the NASA Exoplanet Science Institute (NExScI) and the Space Science Telescope Institute (STScI), the JWST Telescope Allocation Committee (TAC) will award up to 10–15 nights of NASA Keck time during observing semesters 2027B (August 1, 2027–January 31, 2028) and 2028A (February 1, 2028–July 31, 2028) to highly ranked proposals that request observations from both JWST and NASA Keck. The only criterion above and beyond the usual NASA Keck review criteria is that the project must require both data sets to meet the science goals. NASA Keck time will only be awarded in conjunction with new JWST observations (and should not be proposed for in conjunction with an AR proposal).

Unless otherwise stated in the proposal, it is assumed that there is no requirement on the relative timing of the JWST and NASA-Keck observations. A request for contemporaneous or near-simultaneous observations can be made if scientifically justified and technically feasible but there is no guarantee that these can/will be executed.

Joint proposals for JWST and NASA Keck observations should be submitted to STScI as a response to the JWST Call for Proposals. STScI reserves the right to disallow JWST observations that duplicate those approved via any joint program unless the duplications are justified in the original proposals. 

For joint proposals requesting NASA Keck time:

• May request observations in the 2027B and/or 2028A semesters. NASA Keck time awarded to a joint program will be scheduled after the start of the 2027B observing semester (August 1, 2027).
• NASA Keck data collected as part of a Joint Program will have the same Exclusive Access Period (EAP) as the JWST data.
• Keck observations approved through this joint program will be scheduled in a similar fashion to all other NASA Keck programs. NASA Keck observations lost to weather or instrument/telescope issues will not be rescheduled.
• Requests for contemporaneous/simultaneous JWST/Keck observations will be considered but cannot be guaranteed.
• Although teams may propose a similar or the same program to both the NASA Keck and JWST TACs, STScI and NExScI personnel will examine approved programs to avoid duplication of proposals/programs in the use of NASA Keck time.
• Up to 2 partner Keck Target of Opportunity/cadence interrupts can be awarded by the JWST TAC for the time period covered by the 2027B and 2028A observing semesters.
• Major results from these programs should be credited to both JWST and NASA Keck.
• NExScI will not provide funding to successful Joint Program PIs.
• Questions related to NASA Keck time specifically may be directed to keckcfp@ipac.caltech.edu

Some of the instruments available for NASA Keck 2026B observations are expected to be the same for 2027B and 2028A, but proposers should check the above website for the most up-to-date information.

Establishing the technical feasibility of the NASA Keck observations is the responsibility of the PI. NExScI will perform a technical review of the Keck portion of the joint proposals approved by the JWST TAC and reserves the right to reject any approved observation determined to be infeasible, impossible to schedule, and/or dangerous to the telescopes or instruments. Any Keck observations that prove infeasible or impossible could jeopardize the overall science program and may cause revocation of the corresponding JWST time allocation. We, therefore, urge proposers to discuss technical concerns with appropriate staff at both observatories.

Successful proposers for joint JWST-NASA Keck time will be required to submit a WMKO coversheet:

• For observations scheduled in 2027B, the WMKO coversheet must be submitted by mid-April 2027.
• For observations scheduled in 2028A, the WMKO coversheet must be submitted by mid-October 2027.
• Programs with observations scheduled in both semesters must submit both coversheets.

The program title and abstract on the WMKO coversheet must be the same as was submitted in the JWST proposal;  “JWST Joint Program” should be chosen as the allocating institution to make sure that the WMKO proposal ID starts with a "J". It is a WMKO requirement that first-time users of an instrument have at least one lead observer present at Keck for the initial observing run.  Questions related to NASA Keck time specifically may be addressed to keckcfp@ipac.caltech.edu.

Additional APT requirements

In the "Coordinated Telescopes" section of APT, proposers must fill in the necessary NASA Keck nights request.

Additional PDF attachment requirements

In the "Justify Coordinated Observations with Other Facilities" section, proposers must provide a full and comprehensive scientific and technical justification for the NASA Keck portion of their program, including:

• the telescope(s), instrument(s), mode(s), and wavelengths on which time is requested,
• the requested integration time per telescope/instrument, sensitivity, and source of this information,
• a specification of the number of nights for each semester during which time will be required, a breakdown into dark, grey, and bright time, and an explanation of how the required exposure time was estimated,
• information on whether the observations are time-critical, and whether the observations must be coordinated in a way that affects the scheduling (of either the NASA Keck or the JWST observations),
• a description of any special scheduling or implementation requirements (e.g., optimum and acceptable dates),
• the results of the Keck Observatory Archive (KOA) data check. If appropriate archival Keck data exist in the KOA, proposers must provide clear scientific and technical justification for any new Keck observations of previously observed targets. 

Joint JWST-NOIRLab Observing Proposals

The Joint JWST-NOIRLab time is intended to provide investigators with complementary ground-based observations that are necessary in support of their JWST programs. By agreement with the National Science Foundation's National Optical-Infrared Astronomy Research Laboratory (NOIRLab), STScI will be able to award time on NOIRLab facilities to highly ranked proposals that request time on both JWST and NOIRLab telescopes. The award of time on NOIRLab facilities will be subject to approval by the NOIRLab Director, after nominal review by the NOIRLab TAC to avoid duplication of programs. Joint proposals for JWST and NOIRLab observations should be submitted to STScI as a response to the JWST Call for Proposals.  The important additional criterion for the award of NOIRLab time is that both the JWST and the ground-based data are required to meet the science goals of the project. Under this agreement, NOIRLab time will only be awarded in conjunction with new JWST observations (and should not be proposed for in conjunction with an AR proposal). Major results from these programs would be credited to NOIRLab and JWST.

Unless otherwise stated in the proposal, it is assumed that there is no requirement on the relative timing of the JWST and NOIRLab observations. A request for contemporaneous or near-simultaneous observations can be made if scientifically justified and technically feasible but there is no guarantee that these can/will be executed.

NOIRLab has offered up to 5% of its available time to proposals meeting the stated criteria. NOIRLab observing time will be implemented during the NOIRLab observing semesters 2027B and/or 2028A, due to scheduling constraints. Time cannot be requested for the preceding semester, 2027A. Time may be requested only for those facilities listed on the most recent Call for Proposals webpage. In addition, time on heavily-subscribed resources may be limited by the NOIRLab Director.

Establishing the technical feasibility of the proposed NOIRLab observations is the responsibility of the PI, who should review the NOIRLab documentation or consult with NOIRLab directly. All PIs of joint proposals MUST submit the technical description through the standard NOIRLab process by the nominal April 1, 2027 deadline for semester 2027B. For Gemini proposals, a Gemini PIT proposal must be submitted. For all other telescopes, the standard NOIRLab Time Allocation Proposal form must be submitted. Detailed information for Gemini and other telescopes can be found in the Call for Proposals for the 2027B semester (specific semester calls are not posted until 30 days before the next proposal deadline). Proposals not received by the April 1, 2027 deadline may not be scheduled for NOIRLab time.

NOIRLab will perform feasibility checks, and reserves the right to reject any approved observation determined to be infeasible, impossible to schedule, and/or dangerous to the telescopes or instruments. Any NOIRLab observations that prove infeasible or impossible could jeopardize the overall science program and may cause revocation of the corresponding JWST time allocation.

Successful proposers who receive time on Gemini Observatory will have to prepare a Phase II proposal which includes a more detailed description of each observation. Phase II submission instructions will be forthcoming following notification of the results of the JWST review.

Additional APT requirements

In the "Coordinated Telescopes" section of APT, proposers must fill in the necessary NOIRLab nights request.

Additional PDF attachment requirements

In the "Justify Coordinated Observations with Other Facilities" section, proposers must provide a full and comprehensive scientific and technical justification for the NOIRLab portion of their program, including:

• the telescope(s) and instrument(s) on which time is requested,
• the requested observing time per telescope/instrument, a specification of the number of nights for each semester during which time will be required, a breakdown into dark, grey and bright time, and an explanation of how the required exposure time was estimated, including information on filters, gratings, and observing conditions
• information on whether the observations are time-critical, and whether the observations must be coordinated in a way that affects the scheduling (of either the NOIRLab or the JWST observations),
• a description of any special scheduling or implementation requirements (e.g., optimum and acceptable dates).

Technical documentation about the NOIRLab facilities is available from the NOIRLab webpage. Questions may be directed to the NOIRLab Proposal Help Desk by e-mail to proposal-help@noirlab.edu.

For Gemini proposals, in addition to the JWST proposal, this information must be included in a NOIRLab Phase I proposal submitted using the Gemini PIT through the regular NOIRLab submission process. Detailed information for Gemini and other telescopes can be found in the Call for Proposals for the 2027B and 2028A semesters. Gemini proposals not received by the 31 March 2027 (for semester 2027B) or 30 September 2027 (for semester 2028A) deadlines will not be scheduled for NOIRLab time.

Joint JWST-NRAO Observing Proposals

By agreement with the National Radio Astronomy Observatory (NRAO), STScI will be able to award time on NRAO facilities to highly ranked proposals that request time on both JWST and NRAO telescopes. NRAO has offered up to 5% of the available time on its North American facilities, namely the Robert C. Byrd Green Bank Telescope (GBT), the Very Large Array (VLA), and the Very Long Baseline Array (VLBA), for allocation by the JWST TAC in Cycle 6. In return, STScI has offered 50 hours of JWST time for allocation by the NRAO TAC to proposals submitted on or before either of the two NRAO semester deadlines. These time allocations could be updated in future cycles, subject to agreement between both partners. 

GBT MUSTANG-2 is a shared risk instrument and proposals using it should include the instrument team.

Joint observing proposals will be available starting with NRAO Semester 27B (proposal deadline February 3, 2027, with observations commencing in August 2027) and with JWST Cycle 6 (proposal deadline September 2026, with observations commencing in July 2027). Joint proposals will be permitted for the main call for JWST and both semester calls for NRAO. A VLA configuration schedule is published at https://science.nrao.edu/facilities/vla/proposing/configpropdeadlines.

Joint JWST-NRAO Proposals should be submitted to the observatory that requires the larger time allocation. STScI reserves the right to disallow JWST observations that duplicate those approved via any joint program unless the duplications are justified in the original proposals. 

NRAO observing time awarded through the JWST Cycle 6 review will be implemented during the 27B and 28A observing semesters. The award of time on NRAO facilities will be subject to approval by the NRAO Director, after nominal review by the NRAO TAC to avoid duplication of programs. The important additional criterion for the award of NRAO time is that both the JWST and the radio data are required to meet the science goals of the project. Under this agreement, NRAO time will only be awarded in conjunction with new JWST observations (and should not be proposed for in conjunction with an AR proposal). Major results from these programs would be credited to NRAO and JWST.

Starting this cycle, the PI must fill out the following NRAO short form, consisting of high-level metadata, within one week of the JWST Cycle 6 proposal deadline.

Unless otherwise stated in the proposal, it is assumed that there is no requirement on the relative timing of the JWST and NRAO observations. A request for contemporaneous or near-simultaneous observations can be made if scientifically justified and technically feasible but there is no guarantee that these can/will be executed.

Establishing the technical feasibility of the proposed radio observations is the responsibility of the PI, who should review the NRAO documentation or consult with NRAO directly. If approved for NRAO time, the PI must submit detailed observing information appropriate to the relevant NRAO facility. 

NRAO will perform a technical review of proposals approved by the JWST TAC, and reserves the right to reject any approved observation determined to be infeasible, impossible to schedule, and/or dangerous to the telescopes or instruments. Any NRAO observations that prove infeasible or impossible could jeopardize the overall science program and may cause revocation of the corresponding JWST time allocation. We therefore urge proposers to discuss technical concerns with appropriate staff at both observatories. Discussions with NRAO staff should occur via the NRAO helpdesk.

Proposers must always check whether appropriate archival data exist, and provide clear scientific and technical justification for any new observations of previously observed targets. Observations awarded time that duplicate observations already approved by JWST or NRAO for the same time period may be canceled, or data sharing and cooperation among different groups may be necessary, as determined by the two observatories. This includes ToOs with similar trigger criteria, with or without previously known coordinates.

Be aware that some JWST targets might not require new NRAO observations because the joint science goals can be met using non-exclusive access archival data from the VLA, VLBA, or GBT that are available at http://data.nrao.edu. Also note that VLA continuum images from sky surveys at a wavelength of 20 cm and at a FWHM resolution of 45 arc seconds (see http://www.cv.nrao.edu/nvss/) or 5 arc seconds (see http://sundog.stsci.edu/top.html) are available.

All scientific data from NRAO telescopes have an exclusive access period where the data are reserved for the exclusive use of the observing team. This policy applies to NRAO data taken through the joint JWST-NRAO program.

If approved for NRAO time, successful PIs will be contacted by the NRAO Scheduling Officers (schedsoc@nrao.edu for the VLA/VLBA and gbtime@nrao.edu for the GBT). The successful PIs for GBT projects will be responsible for organizing the project's information in the GBT Dynamic Scheduling Software and for carrying out their GBT observations. For the VLA and VLBA, the PIs will be responsible for submitting scheduling blocks to the telescopes' dynamic queues. Projects requiring simultaneous JWST-NRAO observations will be performed on fixed dates. In conjunction with JWST, the NRAO Scheduling Officers will inform the PIs of those dates and times, and the PIs will be responsible for submitting scheduling blocks two weeks prior to the observations.

Additional APT requirements

In the "Coordinated Telescopes" section of APT, proposers must fill in the necessary NRAO hours request.

Additional PDF attachment requirements

In the "Justify Coordinated Observations with Other Facilities" section, proposers must provide a full and comprehensive technical justification for the NRAO portion of their program, including

• the choice of NRAO telescope(s) (VLA, VLBA and/or GBT), and
• the total estimated NRAO observing time in hours.

Detailed technical information concerning the NRAO telescopes can be found at:

• http://science.nrao.edu/facilities/vla
• http://science.nrao.edu/facilities/vlba
• https://greenbankobservatory.org/portal/gbt/

Since the JWST deadline is before the NRAO 2027B call for proposals, please assume the capabilities listed in the NRAO 2027A Call for Proposals. For the VLA, joint proposals may only use capabilities defined as “general observing.” Technical questions about proposing or observing for NRAO telescopes (whose answers are not found in the above links) should be posted to the NRAO helpdesk.

Joint JWST-TESS Observing Proposals

By agreement, STScI will be able to award a limited number of short cadence target slots from the Transiting Exoplanet Survey Satellite (TESS) mission. Currently in its third extended mission, TESS will be observing fields in both the northern and southern ecliptic hemispheres in addition to parts of the ecliptic plane. TESS operates by staring at one part of the sky for two spacecraft orbits (2x approximately 14 days) with the boresight of the four-camera array pointed nearly antisolar. During each of these continuous pointings, referred to as Sectors, TESS collects 200 second Full Frame Images (FFIs) which cover a 24 × 96 degree field of view, and 120-second or 20-second cadence Target Pixel Files (TPF—postage stamps for selected targets of interest. After this ~27 day coverage, TESS slews to observe a different Sector of sky for another ~27 days. All TESS observations are collected in a single, broadband, red- optical bandpass.

Information about the specific TESS pointings for upcoming sectors will be released around September 15, 2026 and will be available on the TESS General Investigator (GI) Program Office website and the MIT TESS website.

TESS 120-second and 20-second targets selected for postage stamps are pipeline processed for background subtraction, and are delivered to MAST as both pixel products and time-series light curve products with no proprietary period. Calibrated TESS FFI’s are observed at a 200 second cadence, provide no target apertures, and have not had scattered or background light subtracted. TESS FFIs are available to the community via MAST with no proprietary period. Programs requiring finer time sampling than the FFI data and/or pipeline processed time-series products should propose to the joint JWST-TESS program and request specific TESS targets. Proposals relying solely on the TESS FFI data do not need to be proposed for through the JWST-TESS joint program.

The joint JWST-TESS program can allocate 120-second cadence observations for up to 1,000 targets and 20-second cadence observations for up to 50 targets. Proposers should identify which targets should be considered for TESS observations and provide an explicit justification that a 120-second or 20-second cadence is sufficient to achieve their science goals. TESS observations will only be obtained for approved JWST targets. There is no guarantee that the JWST and TESS observations will be simultaneous. Joint program targets will be observed by TESS no earlier than the beginning of JWST Cycle 6 observations. Accepted targets will be passed to the TESS GI Program Office by STScI. Additional information about TESS can be found on the TESS GI Program Office website.

Additional APT requirements

In the "Coordinated Telescopes" section of APT, proposers must fill in the necessary TESS targets request.

Additional PDF attachment requirements

In the "Justify Coordinated Observations with Other Facilities" section, proposers must provide a full and comprehensive technical justification for the TESS portion of their program, including:

• the suitability of using TESS survey data products,
• a justification for the selection and number of targets,
• and justification that the 120-second or 20-second cadence will sufficiently meet their science goals.

Technical information on the TESS General Investigator (GI) Program is available on the TESS GI website. 

Joint JWST-XMM-Newton Observing Proposals

By agreement with the XMM-Newton Observatory, the JWST TAC may award up to 200 kiloseconds of XMM-Newton observing time. Similarly, the XMM-Newton Observing TAC may award up to 40 hours of JWST time to highly rated proposals. The only criterion above and beyond the usual review criteria is that the project must be fundamentally of a multi-wavelength nature, and that both sets of data are required to meet the science goals. XMM-Newton time will only be awarded in conjunction with new JWST observations (and should not be proposed for in conjunction with an AR proposal). Proposers should justify the scientific and technical reasons for requesting time on both missions.

If your science project requires observations from both JWST and the XMM-Newton Observatory, you can submit a single proposal to request time on both observatories to either the JWST Cycle 6 or the XMM-Newton Cycle AO-27 review. Joint JWST-XMM-Newton proposals should be submitted to the observatory that represents the prime science facility (not to both observatories). 

Unless otherwise stated in the proposal, it is assumed that there is no requirement on the relative timing of the JWST and XMM-Newton observations. A request for contemporaneous or near-simultaneous observations can be made if scientifically justified and technically feasible, but there is no guarantee that these can/will be executed. 

No XMM-Newton observations with a reaction time of less than five working days from the trigger date will be considered. Target of Opportunity (ToO) proposals must state explicitly whether the JWST observations require a disruptive ToO. No more than one disruptive ToO will be allocated per proposal. It is the responsibility of the PI to inform both observatories immediately if the trigger criterion is fulfilled.

STScI reserves the right to disallow JWST observations that duplicate those approved via any joint program unless the duplications are justified in the original proposals. While there is multi-wavelength expertise in the review panels for both observatories, typically the JWST panels will be stronger in IR science and the XMM panels in X-ray science.

Establishing the technical feasibility of the XMM-Newton observations is the responsibility of the PI, who should review the XMM-Newton Instrument Handbooks. All standard observing restrictions for both observatories apply to joint proposals. For proposals that are approved, both projects will perform detailed feasibility checks. Both projects reserve the right to reject any approved observation that is in conflict with safety or schedule constraints, or is otherwise deemed to be non-feasible.

Additional APT requirements

In the "Coordinated Telescopes" section of APT, proposers must fill in the necessary XMM-Newton kiloseconds request.

Additional PDF attachment requirements

In the "Justify Coordinated Observations with Other Facilities" section, proposers must provide a full and comprehensive technical justification for the XMM-Newton portion of their program, including

• the choice of prime instrument,
• the requested exposure time, justification for the exposure time, target count rates, and assumptions made in their determination,
• information on whether the observations are time-critical.

Technical documentation about XMM-Newton is available from the XMM-Newton webpage.

Pure Parallel

Pure Parallel programs may not include ToO or Future Cycles components.

The JWST GO hours request determines whether the proposal is Very Small, Small, Medium, or Large. Pure Parallel proposals have the same default Exclusive Access Period as regular GO proposals of the same size category.

Proposers are required to use the jwst-pure-parallel package to assess whether their specific observing scenario would have been viable in previous cycles. More information can be found on the JWST Parallel Observations page.

Additional APT requirements

Investigators submitting Pure Parallel proposals must select the "Pure Parallel Proposal" flag on the APT Proposal Information form.

Additional PDF attachment requirements

Proposers should address the value of the data products that will be generated by the Pure Parallel program to the astronomical community in the "Scientific Justification" section of the PDF attachment.

Pure Parallel proposals should follow the same page limit requirements as regular GO proposals of the same size category.

How these proposals are reviewed

All Pure Parallel programs, regardless of size, are evaluated by the Executive Committee; further details on the review process are given in JWST How Your Proposal is Evaluated.

Target of Opportunity (ToO)

A target for JWST observation is deemed a Target of Opportunity (ToO) if it is associated with an event that may occur at an unknown time or in an unknown location. ToOs are distinct from time constrained observations. ToO targets include objects that can be identified in advance, but which undergo unpredictable changes (e.g., some dwarf novae), as well as objects that can only be identified in advance by class (e.g., novae, supernovae, gamma ray bursts, newly discovered comets, etc.). ToOs are generally not suitable for observations of periodic phenomena (e.g., eclipsing binary stars, transiting exoplanets, etc.).

A ToO activation may consist of a single observation or of a set of observations executed with a pre-specified cadence. Information on activating an approved target of opportunity program is in JWST Target of Opportunity Program Activation.

The JWST GO hours request determines whether a ToO proposal is Very Small, Small, Medium, or Large. ToO proposals have the same default Exclusive Access Periods as regular GO proposals of the same size category.

Types of ToOs

The minimum turn-around time for activation defines whether a ToO is Non-disruptive, Disruptive, or Ultra-disruptive. Triggering or activation times are measured from the time when the activation request is submitted to start of the first observation. Due to their significant impact on the JWST schedule, the number of Disruptive and Ultra-disruptive activations are restricted in each cycle.

†This number includes any Ultra-disruptive activations.

*This is the maximum totaled over all accepted programs, not the maximum number of activations that can be requested in any given proposal.

Carry-over ToOs

Standard ToO proposals terminate at the end of each cycle. "Carry-over" status extends the ToO activation window to two cycles (i.e., the current and subsequent cycles); longer activation windows are not possible. Proposers may only apply for carry-over status if the target phenomena have a low probability of occurrence during a single cycle.

If the carry-over ToO activates in the first cycle, the program will terminate after the activation and not be valid in the next cycle. If the carry-over ToO does not activate in the first cycle, it will remain active through the subsequent cycle until activated. If the carry-over ToO does not activate by the end of the second cycle, it will terminate at the close of that cycle.

The request for carry-over status must be made when the proposal is submitted. There is no mechanism for requesting an extension during the cycle. An estimate of the likely probability of occurrence in Cycle 6 (i.e., an annual probability) should be included in the "Special Requirements" section of the PDF attachment. Requests for carry-over status must also be marked with the appropriate flag in APT.

Carry-over status is allowed for Non-disruptive and Disruptive ToOs, but not for Ultra-disruptive ToOs as this would prohibit any new Ultra-disruptive ToOs activations in the subsequent cycle. 

ToOs requesting observations in Future Cycles are not eligible for carry-over status. 

Combinations with other flags

In general, ToO proposals may include additional GO flags, except:

• ToO observations cannot be included in Pure Parallel programs;
• Disruptive or Ultra-disruptive ToOs cannot request Future Cycles observations.

More information about ToO proposals requesting observations in Future Cycles is given below.

Future Cycles ToOs

Future Cycles programs are intended for proposals where observations are required in multiple cycles to achieve the science goals (e.g., the science requires multi-epoch observations with a baseline longer than a single cycle). In the case of Future Cycles ToO proposals, observations are for specific ToO triggers in each cycle (e.g., the trigger for a specific ToO activation is expected to occur beyond the current cycle.). If a ToO is not triggered in the stated cycle, then that time will be dropped from the program.

ToO proposals may not request observations in future cycles if:

• the ToO is Disruptive or Ultra-disruptive;
• the timing of the trigger is uncertain or rare and may or may not occur in the current cycle. Such proposals should request carry-over status instead (proposals may not request both Future Cycles and carry-over status);
• the observations beyond the current cycle are associated with follow-up observations for an object triggered in a prior cycle. Such proposals should be submitted to the corresponding future Call for Proposals.

The proposal size category (and hence the exclusive access period and page limit requirements) is determined by the sum of all hours requested, including those in the future cycles. 

Requests for Future Cycle time should be justified in the "Special Requirements" section of the PDF attachment.

The APT Proposal Information form should indicate the number of ToO activations per observation (using the expandable menu) for each cycle under consideration. Proposers should use the "Future Cycle" drop-down menu to enter the future cycle time and use the "Request custom time allocation" to override the APT calculated allocation for the current cycle. For more information, see JWST Filling Out the APT Proposal Form.

Additional APT requirements

Investigators submitting ToO proposals must fill out the "Number of Target of Opportunity Activations" expandable menu on the APT Proposal Information form; for more information, see JWST Filling Out the APT Proposal Form.

Minimum and maximum ToO response times must be specified in the APT Special Requirements.

Additional PDF attachment requirements

ToO proposals must provide a clear definition of the trigger criteria and present a detailed plan for the observations to be performed in the "Description of Observations" section of the PDF attachment if the triggering event occurs.

The "Special Requirements" section of the PDF attachment must include:

• identify whether the ToOs are (ultra-)disruptive or non-disruptive;
• clearly state how soon JWST must begin observing after formal activation;
• the likely probability of occurrence in Cycle 6 (i.e., an annual probability) if carry-over status is requested; and
• any requests and justifications for observations in Future Cycles.

ToO proposals should follow the same page limit requirements as regular GO proposals of the same size category.

How these proposals are reviewed

All ToO proposals, regardless of size, are evaluated by the Discussion Panels; further details on the review process are given in JWST How Your Proposal is Evaluated.

Treasury

Treasury proposals are those designed to create JWST datasets of lasting scientific value. A Treasury program is defined by the following characteristics:

• The program should focus on the potential to solve multiple scientific problems with a single, coherent dataset. It should enable a variety of compelling scientific investigations.
• The program should produce data products that are processed or calibrated significantly beyond the capabilities of the JWST Calibration Pipeline to maximize the scientific impact of the program. Examples include tiled images, multi-band object catalogs, or coordinated observations on other facilities (for which some funding can be provided for US investigators). Funding for the proposed data products will depend on their timely availability. They should be delivered to STScI in suitable digital formats for dissemination via the Mikulski Archive for Space Telescopes (MAST).
• Data taken under a Treasury program will usually have no Exclusive Access Period, although a brief Exclusive Access Period may be requested if it will enhance the public data value; that request must be justified in the "Special Requirements" section of the PDF attachment and will be subject to TAC review. 

The following additional characteristics are particularly encouraged:

• Development of new techniques for data reduction or analysis.
• Creation and dissemination of tools (software, Web interfaces, models, etc.), beyond what is offered to the community by STScI, for the scientific community to work with the data products.

The emphasis will be on observations whose value is maximal if taken in the current cycle. However, Treasury proposals may request observing time to be distributed in future cycles if scientifically required (as a Future Cycles proposal). 

Treasury programs can be Very Small, Small, Medium, or Large proposals.

Additional APT requirements

Investigators submitting Treasury proposals must select the "Treasury" flag on the APT Proposal Information form and include additional technical details on the scheduling aspects of their program in the “Proposal Observing Description” section in APT.

Additional PDF attachment requirements

The "Scientific Justification" section of the proposal's PDF attachment should include a description of the scientific investigations that will be enabled by the final data products, their importance, and value to the astronomical community. The "Description of Observations" section should not only include a detailed rationale of the observations, but also plans for data analysis and a description of how the data products will be made available to STScI and the community, the method of dissemination, and a realistic time line. Requests for a non-zero Exclusive Access Period must be justified in the "Special Requirements" section.

Because of their scale, Treasury programs have increased page limits, as detailed in JWST Preparing the Proposal PDF Attachment.

How these proposals are reviewed

All Treasury GO proposals, regardless of size, are evaluated by the Executive Committee; further details on the review process are given in JWST How Your Proposal is Evaluated.

Next: JWST Survey Proposals