Keck Call & Proposal Instructions


Participating in The Pilina and Kōkua Initiative

Starting in 2024B UC is partnering with Caltech and Keck Observatories to create The Pilina and Kōkua Initiative, a pilot project to facilitate observers from our constituencies to travel to Hawaiʻi, observe at WMKO headquarters, meet and perhaps give informal talks to WMKO staff about science and their scientific program, and most importantly participate in Hawaiʻi community activities. The Pilina (relationship to people and place) and Kōkua (to help in ways that are called for) Initiative will provide travel support for observers for the period of their observations in addition to two extra days to provide time for connection and service to people and place. Participants will spend at least one full day devoted to community engagement programs while at WMKO.

For more information about this program please visit the UC Pilina and Kōkua Initiative  page.

Latest Keck Call for Proposals

Call for Proposals: UC time on the Keck telescopes

Semester 2024A (Feb. 1, 2024 through July 31, 2024)

Deadline: Proposals are due on Thursday, Sept. 21, 2024 by 5:00pm PT

1.1 Due Date

Proposals for UC observing time on the Keck Telescopes for Semester 2024A are due by 5:00 pm PDT on Thursday, September 21st, 2024.  There will be 58.5 nights available on K1 and 55.5 nights available on K2 spread evenly across the semester and lunar phase.  There are 7 one-hour Partnership ToO interrupts available.    A PI may ask for a larger number of UC-time only ToO interrupts as well.   

1.2 Proposal Process

NOTE:  Changes for new LMAP proposals:   Once a proposal has been granted LMAP status, the team must submit a Collaboration Management Plan to the Director’s Office within 2 months. It is not the intent of this policy to require specific terms in CMPs, but  to ensure that collaboration policies are known to members and clearly defined.  The plan should include:

  • Publication Policy indicating how authorship and co-authorship is determined/merited.   This should include when this policy will no longer apply, ie. what will the publication policy be once the LMAP data collection is over or proprietary periods have expired.
  • How collaboration leadership is structured, e.g. a single PI, committee, rotating spokesperson, etc.
  • How membership in the collaboration is determined
  • Code of Conduct for the collaboration members and how issues with code of conduct violations will be arbitrated.
  • An acknowledgement that the policy has been shared with all members of the collaboration (including early career researchers.)

This plan can mirror or reference other research organization’s plans/codes, e.g. SDSS, AAS, KSM; or can be entirely new.  The Collaboration Management Plan can take as many pages as required, but may be as short as 1-2 pages.   The UCO Director will appoint a group to review the Collaboration Management Plan (CMP) for completeness.  If clarification or changes are recommended by the review committee the LMAP team will have adequate time to respond before the next semester.  The final accepted CMP will be published on the UCO LMAP web pages.

NOTE:   PIs should generally ask for only the number of nights (or portions of nights) needed to complete their experiment and be sure to fill out and update the cover sheet with the number of nights needed to complete the experiment beyond this request.   If your experiment has a compelling reason to include extra time (such as weather losses) be sure to explain this clearly in

Section 2.1 of the proposal.

NOTE:   Since the weather losses at Keck are typically low and rare, the PIs should request for only the time they need to complete their experiment.   However, if the PI has a compelling argument about why they must inflate their request by the weather losses (such as sharing the weather losses across several programs in a mini-queue) then the PI could make an argument for its inclusion for the TAC to consider.

The principal consideration in evaluating proposals will be the scientific merit of the proposed project. Projects that take maximum advantage of the unique capabilities of the Keck Telescopes will be given high weight. A brief description should be given of backup programs that will be carried out if conditions are not suitable for the primary program. Please see which describes the UC online proposal submission process, and which describes the required sections and their page limits. The Time Allocation Committees take page limits very seriously, so please pay close attention as you draft your proposal.

Keck is continuing the login-password system to allow you to retrieve and modify your coversheets. Returning observers should use the same account information as last semester. New observers may request an account from the page

The coversheet form is available through the login page link above. Once you have created a coversheet and you are logged in, please go to the instructions for submitting Keck proposals at: to create the rest of your proposal as a PDF file to upload to the UC proposal server. Note that the coversheet has been modified again this semester, so please pay close attention when filling it out.

You may use the extra page allocated to the project update if this is a resubmission to respond to the previous TAC comments, even if the previous submission was unsuccessful.  It would be useful to mention the previous proposal title (if different), PI (if different) and proposal number.    

1.3 Be Kind to your TAC Members

Please read the page limits carefully on the keck-guidelines web page ( and adhere to them. TAC members will be instructed to stop reading any text beyond the stated page limits. Note that the text format is 12 point font; single-spaced; one-inch margins.

Although there is not a formal limit on the number of Keck proposals that one PI can submit, experience has shown that TAC members view one PI submitting numerous proposals as a real burden on the reviewing process; it generally does not increase the odds of a PI getting Keck time. Please use moderation.

1.4 Time Domain Astronomy (TDA)

Observers will continue to have the ability to propose both Target of Opportunity (ToO) and Cadence programs using the Keck Cover Sheet. Keck policies related to Target of Opportunity (ToO) and Cadence proposals can be found at and

If your project involves both Classical and TDA observing, you MUST put in two separate cover sheets so that the Keck TDA software can clearly distinguish between the two. Instead of submitting the same text twice, please submit the actual proposal text under the Classical cover sheet; the text submitted under the TDA (ToO or Cadence) cover sheet should merely include the proposal title, PI, and proposal number, together with a sentence stating that the main text can be found under the proposal number of the Classical cover sheet. The Cover Sheet form will not let you submit one proposal requesting both Classical and TDA observing time.

For Semester 2024A, two types of ToO requests can be made.  TAC- approved ToO projects which are able to interrupt observers at any of the four institutions, to increase the utility of the ToO process. These are called Partnership ToO proposals. There is a limit to the number of Partnership ToO interrupts.   The second kind of TAC approved ToO program (Institutional) can only interrupt UC programs.   Note that there is not a limit to the number of “Institutional” ToO interrupts of fellow UC observers. But because UC nights are only a fraction of the total available Keck nights, the probability of a successful ToO interrupt using UC time alone is smaller than for Partnership ToOs. Also note that UC Institutional ToO time can be interrupted by a Partnership ToO, so think through your strategy carefully.   Both Partnership and Institutional ToO interrupts are counted in full 1 hour increments even if less than 1 hour of time is used.  All ToO proposal requests should be made in units of 1 hour interrupts.

In 2024A, partial-night observations can be interrupted. The Keck guidelines state that “Individual TACs may designate a few nights (partial or whole) as exempt from ToO interrupts. This designation must be scientifically motivated, namely that such interruptions would seriously compromise the scientific return of the entire observing time. Proposers should make any such requests to their individual TACs as part of their observing proposal. Use of these exemptions is expected to be rare.” So if you think your project deserves, for scientific reasons, to have one of these rare exemptions from interruptions, please state so in your proposal and give a very strong justification for your request.

1.5 Cadence Observations

Keck’s policies for Cadence observing ( are reasonably complicated. These include a new category called “Partnership Snapshot” observatories. If you are contemplating applying for Cadence time, please read the guidelines carefully.

Keck continues to reconcile cross-institutional cadence and ToO allocations. Scheduled cadence time is returned to the institution at a one to one rate, and ToO time is returned at a rate of two hours for every one hour interruption because the ToO PI will not choose to call for a trigger if the weather is unacceptable.

1.6  Twilight Cadence Observations

In 2024A, institutions will continue to be able to allocate one twilight observing program per telescope, for a total of up to two programs.  On Keck I, OSIRIS-NGS (imager only) will be available, and on Keck II, NIRC2-NGS will be available.  Please note that due to ongoing AO upgrades, there will be times in the semester when AO is unavailable for cadence observations (see above). Cadence program PIs are responsible for development of instrument scripts, providing documentation, and training of staff needed to make the cadence program a turnkey operation.

1.7 Large Multi-Year Projects

UC LMAP observing projects with well-defined scientific objectives that require a large number of nights to bring to completion (normally 10 or more nights per semester). The UC LMAP program allows projects extending for more than one semester to be carried out with multi-year approval from the beginning. LMAPs should generally be directed toward obtaining a high quality, coherent, homogeneous data set that will allow scientific questions of major importance to be addressed in a thorough, systematic manner. Please consult for current policies regarding LMAPs.   Please note the additional requirement of inclusion of a Collaboration Management Plan listed at the top of section 1.2.

1.8 At-Home (pajama mode) Observing

At-home observing will continue to be available to observers.  Please see for information about remote observing, including at-home observing.

2.0 Notes on Instruments and Availability

See the following web page for detailed notes on the availability of instruments for 2024A:


KPF:  KPF will be unavailable for 3 weeks in February while the instrument undergoes a service mission. 

Keck I AO: Keck I AO (Osiris) may require periods of downtime in 24A to help facilitate KAPA work. Observing programs may be moved from preferred to acceptable observing periods to provide time for this work.

NIRSPEC: Nirspec will be unavailable from February 1- March 9 for routine servicing to remove ice from the dewar window.

Keck II AO:  Keck II AO (Nirc2, Nirspao) will be unavailable for 3 weeks in late February – mid March.

DEIMOS: Please see for the latest DEIMOS detector performance status.

KPIC: KPIC will be unavailable until April, and will only be available for shared-risk science in collaboration with and supported by the KPIC team.

ESI:  ESI will be scheduled in campaign mode to limit the number of reconfigs through the semester.

NIRSPEC/NIRSPAO:  Nirspec and Nirspao nights may be scheduled in campaign mode to limit the number of reconfigs into AO during the semester.

NIRC2:  The vortex coronagraph in LGS mode is not available. Please, see the NIRC2 manual ( for information about vortex operations.

Notes regarding Subaru facility and instrument availability in 24A:

– From 2024A, Subaru will charge 30% of weather factor for the allocation of HSC queue mode programs, to increase the average completion rate of the programs. This means that 1 night is defined as 7 hours (including overhead) in the case of HSC queue mode. Accordingly, the requested time in HSC queue mode should not exceed 3.5 nights (requesting 3.5 nights science time corresponds to 5.0 nights total request, which is the maximum request allowed for Subaru “normal” programs). HSC programs requesting classical allocation do not need to consider this weather factor.

– There may be 14-27 nights of downtime due to the inspection of the hydraulic system of the telescope and dome drive system renewal (most likely in June-July).

– For facility instruments, HSC, HDS, IRCS(+NGSAO/LGSAO), FOCAS, MOIRCS will be available. LGS+AO with TBAD (Transponder Based Aircraft Detector) is available with a shared-risk policy.

– There will be at most three (3) or four (4) HSC observing runs in S24A, depending on the number of PFS commissioning runs and the schedule of the facility maintenance works.

– For PI-type instruments/device, CHARIS, FastPDI, IRD, MEC, REACH, VAMPIRES, NsIR Wave Plate Unit, and NIR WFS will be available for S24A.

As usual, proposals requesting PI-type instruments/devices must include the relevant instrument PIs in the proposal. CHARIS, FastPDI, VAMPIRES, and MEC can be used together at the same time as the modules of SCExAO.

– A new NIR WFS (a visiting device, a near-infrared wavefront sensor inside the AO188 instead of the visible wavefront sensor) will be offered with a shared-risk policy.

Instructions for Submitting Keck Proposals

1. Proceed to the Keck Observer Login Page. Login using an existing Keck observer account (or, if necessary, create a new account and login). Find the Cover Sheets section and submit a new Cover Sheet, or select an existing Keck Cover Sheet to be updated and re-used. Follow the instructions to prepare and submit the Keck Proposal Cover Sheet.

The “Allocating Institution” should be one of the UC options (in order to send the Cover Sheet to the UCO web server). Please ensure that the e-mail addresses of the PI and all Co-Is are valid; this is important for subsequent processing of the proposal by the UCO web server.

Take note of the Keck Cover Sheet Id that is assigned for the proposal.

After submission at Keck there is a delay, typically of some minutes, while the Cover Sheet is transferred from the Keck web server to the UCO web server for the next steps. The UCO web server can only accept proposals after it receives the Cover Sheet from Keck, so be sure to do this step before the deadline.

2. Prepare the body of the proposal containing the Scientific Justification, figures, Technical Comments, Results from Previous Keck Runs. Please see the UC Keck Proposal Guidelines for the full set of instructions.

The top line of the proposal must contain the PI name, the assigned Keck Cover Sheet Id, the proposed instrument(s) and the requested number of nights.

This proposal must be a PDF file.

3. Go to the UC Keck Proposal web page.

Enter the e-mail address of the PI (or a Co-I) as listed on the Keck Cover Sheet, the Keck Cover Sheet Id, and click the “Proposer Login” button.

Click the “Submit (or resubmit) a TAC Proposal File” button. Use the web browser file chooser to select the PDF file with the proposal that is on the local machine running the browser. The submission web page will give an opportunity to review the PDF file that has just been uploaded.

Note: The UCO web server will accept multiple revisions of the proposal PDF file until the deadline; simply return to the web page and submit the new version. The Keck web server will accept edits to modify an existing Cover Sheet; that will preserve the Cover Sheet Id and the connection with the proposal submitted to the UCO web server. The instructions for this are found at the Keck Observer Account web pages. (If a new Cover Sheet Id is created at Keck then the UC web server must receive a proposal for that new Cover Sheet Id.)

4. After the proposal has been uploaded to the UCO web server it will send e-mail confirmation to the PI and all Co-Is listed on the Keck Cover Sheet. Please watch for this confirmation.

If you have any issues with the Keck CoverSheet please contact

If you have any technical problems with the proposal software please contact

If you have questions about policy, procedure or suggestions for improving the proposal system please contact Deputy Director Matthew Shetrone.