2022B Call for Proposals

for NASA-Allocated Observing Time on the Keck Telescopes

Proposals are due Thursday, March 17, 2022 by 4 pm PDT

Online Submission Page

Key Dates in 2022

Thursday, February 17: 2022B Call for Proposals available

Thursday, March 3: Deadline to request the required letters of support from NASA HQ for General Mission Support proposals.

Thursday, March 17 by 4 pm PDT: All proposals and supporting letters due to NExScI by 4 pm PDT

Highlights for 2022B:

  1. Dual Anonymous Proposal Review (DAPR): Starting last semester, the NASA Keck TAC is using a DAPR process. Proposers now prepare two documents: an anonymized Science Program and a non-anonymized Expertise and Access document. In addition to this Call for Proposals, the following resources are provided to assist proposers with the implementation of DAPR.
  2. Time Domain Astronomy and Target of Opportunity programs: Observers can propose for both Time Domain Astronomy (cadence) and Target of Opportunity (ToO) programs. See Section IV for important details on cadence requests as well as the number of ToO interrupts allowed each semester.

    Please note that due to ongoing AO upgrades, there may be times in the semester when AO is unavailable for cadence observations. 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.

  3. Twilight Observing: Keck has a program for acquiring snapshot observations in morning twilight. The available instruments for twilight observing are OSIRIS-NGS (imager only) on Keck 1 and NIRC-NGS on Keck 2. The program is designed to accommodate extra infrared observations during normally scheduled visible observations, when those observations end early and surrender the last portion of the night. Each institution is limited to one (1) program per partner institution per semester. Programs designed for longer term (> 1-2 years) will be given priority.
  4. At-Home ("pajama mode") Observing: As was started during the pandemic, Keck will continue to support up to two observers for at-home observing: one primary and one secondary observer. Additional observers can join but cannot launch the VNC control system for the instruments. At-home observing requires the installation of software which only runs on Linux and macOS operating systems. At-home observers will be contacted by Keck staff and should work with this staff to install and test the software several days ahead of their run to allow time for troubleshooting.

    Pajama mode is also available to first time observers although they are strongly encouraged to travel to Keck for their observations if possible.

  5. Semester Notes and Considerations for Keck/Subaru:
    • Keck I Telescope: There will be a 12 night period of shutdown and engineering occurring in either September or October bright time in order to conduct repair work on the Keck I telescope pier.
    • KCWI: KCWI will be unavailable during the 22B semester for the installation and commissioning of the red channel, KCRM.
    • NIRSPAO/NIRSPEC: Nirspec and Nirspao nights may be scheduled in campaign mode to limit the number of reconfigurations into AO during the semester.
    • NIRC2: The vortex coronagraph in LGS mode is not available. The vortex coronagraph with the PyWFS is only available through collaboration with the PyWFS and vortex development teams.
    • DEIMOS: The top-left CCD on the detector mosaic is noisier than the rest of the CCDs. Read here for guidelines on how to design MOS masks with this issue in mind.
    • Subaru Telescope Downtime: The Primary Mirror recoating and some maintenance work are planned from July 11 to September 30, 2022.
    • Other than this period of downtime, the Subaru-Keck exchange will continue as previous semesters with flexibility as to the number of nights available for exchange. Please see the available instruments page for complete information on Subaru.

Table of Contents

I. Guidelines for Allocation of NASA Keck Telescope Time

NASA announces this call for proposals to use its share of observing time at the W. M. Keck Observatory. This call for semester 2022B (August 1, 2022-January 31, 2023) will allocate 31.5 nights of observing, with planned allocations of 16.5 nights on Keck 1 and 15 nights on Keck 2, distributed evenly across dark, grey, and bright time. Typical over subscription rates range from 3:1 to 5:1.

Proposals are due on Thursday, March 17, 2022 at 4 pm PDT and should be submitted via the online submission site. using these required templates for the Science Program (available in Word or Latex format) and the Expertise and Access document (available in Word or Latex format).

Ia. Strategic Use of NASA Keck Time

NASA intends the use of its time allocation on the Keck telescopes to be highly strategic in support of on-going missions and/or high priority, long-term science goals as described in the Science Mission Directorate's 2020 Science Plan and in the documents linked below for each science area.

The scientific areas in which proposals are solicited are:

  1. Investigations in support of Exoplanet Exploration (ExEP) science goals and missions to discover and characterize planetary systems and Earth-like planets around nearby stars;
  2. Investigations in support of Cosmic Origins (COR) science goals and missions to study how stars and galaxies came into being;
  3. Investigations in support of Physics of the Cosmos (PCOS) science goals and missions to explore the most extreme physical conditions of the universe, from black holes to dark energy;
  4. Investigations in support of Planetary Science (PS) science goals and missions to study our own solar system.

Within these science areas, two types of proposals for NASA Keck observing time will be accepted for semester 2022B:

  1. General observing time proposals
  2. General Mission Support proposals (see Section IIb )

As noted above, in addition to astrophysics investigations, proposers are encouraged to consider compelling planetary science investigations, especially those supported by the last Planetary Decadal Survey. Proposers should identify how the observations contribute to the body of scientific knowledge needed to help refine objectives of future missions and aid in the understanding of the origin or evolution of the targeted body. Observations should be of lasting importance to the broad planetary community.

Proposers should base their science case in terms of strategic relevance toward achieving one or more of NASA's goals in the science areas listed above. Gradations of strategic relevance are listed below. In the "NASA Strategic Relevance" section entered on the submission site, please note and give evidence for the level your program matches; a numerical grade will be assigned for strategic relevance.

  • This program is critical to support NASA Missions or programs, e.g. in support of approved NASA space observations that enable the mission to achieve its Level 1 Requirements such as validation and characterization of transiting exoplanet candidates from Kepler and TESS;
  • This program adds significant value to, or enhances, existing NASA data/missions/facilities by, for example, carrying out a follow-up redshift program for objects detected in deep imaging surveys from HST, Chandra or Spitzer; following up on transient events such as gamma ray bursts or gravitational wave sources detected or localzied by SWIFT or Chandra, or validating and characterizing targets important for planning future observations (e.g. JWST target selection), or provides data which directly addresses a NASA strategic goal;
  • This program generically supports NASA's broader science goals.

General Observing and Mission Support programs requiring many nights of Keck time over multiple semesters (up to 4 semesters) may be submitted, but must explicitly justify their strategic connection to the stated goals. Read further about multi-semester proposals in Section III below. Allocations beyond 2022B depend upon the successful renewal of the NASA-Keck Cooperative Agreement Notice (CAN) in February 2023.

Within these broad guidelines, the allocation of time will be based on scientific merit, strategic importance, resource availability, and the uniqueness of Keck's capabilities for the investigation. All proposals for NASA Keck time will be evaluated by scientists on the NASA Keck Telescope Allocation Committee (NASA Keck TAC), with the TAC process administered by the NASA Exoplanet Science Institute (NExScI). In recognition of the science communities that NASA Keck time is expected to serve, TAC members are selected to ensure balanced expertise in the areas of exoplanets, solar system objects, and in support of NASA's Cosmic Origins and Physics of the Cosmos goals. NASA's proposal solicitation and their evaluation by the NASA Keck TAC will be phased to meet the telescope scheduling requirements set by the Director of the Keck Observatory.

Ib. Applying for Observing Time

The opportunity to propose as Principal Investigators (PIs) for the NASA time on the Keck Telescopes is open to all U.S.-based astronomers, i.e. those with their principal affiliation at a U.S. institution. All proposals for NASA Keck time must comply with the criteria outlined in the following sections.

Starting with semester 2022A, the NASA Keck proposal review follows a Dual Anonymous Proposal Review (DAPR) process. Please see the highlights above for a list of resources supporting DAPR.

Proposals received by the application deadline will be reviewed and ranked by the NASA Keck TAC. The TAC will submit their recommendations to the selecting official, the NExScI Executive Director, for final selection. NExScI will coordinate the final selections with WMKO for scheduling.

For a complete NASA Keck proposal, PIs will submit the following documents as well as the information requested on the submission page.

  • Anonymized Science Program
  • Non-anonymized Expertise and Access Document
  • A PDF of the WMKO Cover Sheet generated through the WMKO Observer Login Page. Please verify that the proposal number on your WMKO cover sheet reflects the current semester and contains an "N" indicating that you are applying for NASA time.
  • Mission Support Letters for General Mission Support proposals if submitting one of these proposals.

The Science Program and Expertise and Access (E & A) documents must use the templates linked below, be written in 12-point font with 1-inch margins and follow the sections and page limits listed below:

Science Program ( Word template & Latex template )
  • Science Case: up to 2 pages
  • Instrument Request: up to 1 page
  • Figures and Tables: up to 1 page
  • References: up to 1 page (only for references specific to the anonymous Science Program)
  • List of target stars/objects (Epoch 2000)
Expertise and Access Document ( Word template & Latex template )
  • Team Expertise: up to 1 page
  • Access to Keck or Subaru Time: up to 1 page
  • Progress Report for Ongoing or Recently Completed Keck Projects AND Status of Allocated Time on Large Telescopes: up to 1 page
  • References: up to 1 page (only for references specific to the E&A document that are not included in the Science Program references)

Proposals that violate the page limits will be evaluated solely on the information on the allowed pages and will likely receive a lower ranking from the TAC, and in extreme cases may be returned as non-compliant.

Proposers should submit the PDFs of their Science Program and Expertise and Access Document using the online proposal submission form which includes the following fields for:

  • The proposal abstract. The abstract does not need to be repeated in the body of the proposal.
  • A statement on the relevance of the proposed science to NASA's Strategic Goals.
  • A statement why public data in the Keck Observatory Archive are insufficient to meet the science goals of the proposal. See KOA Check section below.

Note that text in all of these fields should be written in DAPR format.

Shortly after proposal submission, you will receive an email acknowledgement with attached PDFs of the anonymized and non-anonymized versions of your proposal as received at NExScI. Please email if you do not receive the confirmation email or experience problems. Information on the NExScI cover page may be made public for accepted proposals.

Ib.i Science Program (Anonymized)

The Science Program should outline the science and technical case for the proposed program using this template available in Word template and Latex template. These Guidelines for Proposers will assist with writing an anonymized proposal. The scientific case for observing time should establish four things:

  1. The scientific question(s) toward whose solution the observations are requested, along with how these questions fit into the larger scientific context;
  2. How the measurements requested will be used to illuminate these questions;
  3. How the proposed science relates to other work in the field, and will advance the field;
  4. How the proposed science fits into NASA's strategic goals as listed above.

The technical case should demonstrate that the proposed measurements are technically feasible, given the performance of the proposed instrument(s), in the time requested. Mission Support proposals must include additional supporting materials as described here.

Specific points that must be addressed include:

  • Why the Keck Observatory and the proposed instruments are essential for the proposed observations
  • The required spatial, spectral, and temporal range and resolution of the proposed observations
  • Estimates of the signal-to-noise required and expected, and justification for the number of nights requested for the entire program, as well as exposure time justification
  • If requesting less than full nights, indicate which portion of the night is requested (in Hawai'i ST)
  • Cadence/Target of Opportunity justification, if needed
  • Scheduling flexibility/date specific observing and back-up/descope plans, if applicable. Information can be summarized in a table for clarity.
  • If new or unusual techniques are to be used, make clear how observations and calibrations will be obtained
  • Any other information that may assist the TAC in evaluating the scientific merits of the proposal and its suitability for the Keck Telescopes
  • All applications must include a complete and well-justified target list with sufficient information (magnitudes, coordinates) to determine scheduling within the semester, including which part of the night is requested if asking for less than full nights. Applications without such lists will be rejected. In the case of ToO targets or sources being drawn from on-going surveys (e.g. TESS) or very large samples of sources (e.g. from deep extragalactic fields), a description of the nature and location of the potential targets must be provided in sufficient detail for the TAC to make a thorough review.

The proposal should be aimed at someone who is not a specialist in the particular area of astronomy under study. A specific scientific case with a connection to the bigger picture, rather than a broad general one, is usually more successful.

In order for a proposal to be recommended for scheduling, the proposal must have both a high science and a high strategic grade. The TAC evaluates the scientific merit of each proposal separately from the strategic merit, so successful proposals must present a strong and coherent scientific case.

Ib.ii Expertise and Access Document (Non-anonymized)

As part of the DAPR process, NExScI is requiring that proposers submit a non-Anonymized Expertise and Access (E&A) document in addition to the anonymized Science Program. The E&A document must use this template available in Word template and Latex template.

Team Expertise

The one-page team expertise document should demonstrate that the proposal team has the requisite expertise to make the observations and reduce the data in a timely manner. It should include the team's expertise in the following: Keck instrumentation, data reduction and analysis/modeling, and observational experience. For proposals with a large number of Co-Investigators, it is not necessary to report on the qualifications of every team member, only those conducting or leading major aspects of the proposed study. A biography of each team member is not needed.

Access to Keck and Subaru Time

Proposals from PIs, or any Co-Is, who have access to the Keck or Subaru (if applying for Subaru time) telescopes through other partners, specifically the University of California, Caltech, Yale, Keck Observatory, Swinburne, and the University of Hawaii, are accepted by the NASA Keck TAC. However, the Expertise and Access document must specifically include:

  • Why time beyond the allocations available through their institution(s) is required;
  • • If you have institutional Keck time, how is it being used for the proposed project; i.e. all being used for the proposed project, some being used for the proposed project, none being used for the proposed project;
  • How the program is using any other Keck/Subaru telescope time awarded within the last two years for the proposed project.

The TAC may use access to non-NASA Keck/Subaru time as a factor in determining the final grades and rankings of the proposals. The ability to achieve the science objectives with and without NASA time could be either a positive or a negative factor. If NASA time provides only a small fraction (<< 50%) of the observing time needed to complete a project, the TAC might conclude that NASA time is not crucial to the completion of scientific goals and the proposal may receive a lower ranking in comparison to a project that completes its goals within the NASA allocation. However, if the PI can leverage access to NASA and non-NASA time to address science aligned with NASA's strategic goals that could not be addressed with NASA time alone, the proposal could receive a higher ranking. In the case of two proposals ranked equally on scientific and technical merit, the TAC might use access to additional Keck time as one of the factors in determining the final ranking.

Failure to account for your appropriate level of access to non-NASA Keck time, both on the submission page and in the text of the E&A document, will cause the proposal to be rejected as a non-compliant submission.

Progress Report for Ongoing or Recently Completed Keck Projects AND Status of Allocated Time on Large Telescopes

No more than one page should be used to summarize the PI's and key Co-I's current involvement on existing Keck research programs to inform the reviewers of the status of completed and planned observations, data analysis, and publications. A similar summary should be made for other relevant large or space-based telescope time that has been awarded during the past two years.

Ib.iii KOA Check

In order to use the NASA time on the Keck telescopes as efficiently as possible, proposers must verify, while being DAPR compliant, that their science goals cannot be met through public observations already in the Keck Observatory Archive (KOA). To do this, the PI must enter text into a box on the submission page explaining why data contained in KOA are not sufficient to meet their science goals.

Reasons why additional or different data are needed could be related to, but are not limited to, the cadence, timing, or depth of the archived observations, or the wavelength range or observation mode in which the data were taken. PIs who are proposing solar system or other target observations in order to investigate changes over time, can state this without checking the archive. Proposers with large survey programs should describe KOA results for a representative sample of their targets.

To see what data are contained in KOA, please use this link and enter your target list according to the directions.

Ib.iv HIRES PRV Configuration

HIRES is available in a dedicated precision radial velocity (PRV) configuration. HIRES data collected in this prescribed HIRES-PRV configuration will be compatible with the public radial velocity pipeline processing environment available at NExScI which will produce wavelength-calibrated 1D spectra and time-series of relative PRVs.

There are several important considerations for observers wishing to use the HIRES PRV configuration; only data collected in the specified HIRES-PRV configuration and data collected according to the recommendations summarized below can be processed properly in the NExScI HIRES processing environment.

Full documentation of the instrumental setup for the HIRES PRV configuration and the use of the HIRES PRV processing environment can be found here. Questions regarding the HIRES PRV configuration or PRV processing may be directed to Dr. David Ciardi at NExScI.

Ib.v Notification and Program Support


Applicants will be notified of the outcome of the proposal review in early June or early December depending upon the semester. Successful applicants are encouraged to initiate communications with the WMKO technical staff to ensure that valuable Keck telescope time is used efficiently from your first time on the telescope.

Program Support

Contingent upon funding from NASA Headquarters, PIs of programs assigned time through this Call for Proposals will received limited research and travel support. Funding awards will be determined through formulaic means. Target of Opportunity and twilight observing programs do not receive financial support since the observations may never be triggered.

NExScI will manage the Keck PI Data Awards (KPDAs) and will contract with the Jet Propulsion Laboratory (JPL) to administer the disbursement of most of the funds. Depending on the size of the award and the nature of the PI's home institution, the funding instrument used by JPL will, in most cases, be a Research Support Agreement (RSA). An RSA is a simple Fixed Price, Advance Paid, subcontract provided through JPL that is used for basic research funding where scientific reports and technical data are the only deliverables. RSAs can be awarded to educational and non-profit institutions. Proposals should not include any budget information.

Final Report

The only reporting necessary for KPDAs is a required "end of contract" report outlining the work done and any resulting publications. Please use this final report template to ensure that all relevant information is included. Failure to submit a final report in a timely manner may be grounds for rejection of observing proposals in subsequent years. Final reports should besubmitted online.

II. Proposals in Support of NASA Space Missions

IIa. Key Strategic Mission Support (KSMS) Proposals

NASA has solicited proposals for large Key Strategic Mission Support programs in four previous semesters: 2016A, 2018A, 2019B, and 2022A. Abstracts of the KSMS programs selected in these semesters can be read here. There is no KSMS solicitation for the 2022B semester. The next solicitation for KSMS programs is expected to be for semester 2024A.

IIb. General Mission Support Proposals

The NASA Keck TAC accepts General Mission Support proposals every semester. These proposals must demonstrate that the proposed observations provide critical and timely support for confirmed (i.e. at least Phase B) and operating NASA space missions only. In this case, "critical" refers to NASA Keck data meeting one or more of the following criteria:

  1. Essential to achieving Level 1 Requirements of the mission, e.g. Kepler follow-up at Keck being essential to validate and characterize planet candidates, validating WISE completeness/reliability right after launch, gathering data during LCROSS lunar impact;
  2. Essential to mission planning activities including those affecting the health, safety, and risk mitigation of NASA assets, e.g. looking for potentially harmful debris in the rings orbiting Pluto that might endanger the New Horizons spacecraft;
  3. Parallel/coordinated observations with NASA assets required for time critical events and/or for independent validation and verification of the space mission data, e.g. to support SOFIA observations of Pluto multiple occultations;
  4. Longer term mission planning, e.g. looking for Kuiper Belt objects that New Horizons could fly to after its encounter with Pluto;
  5. Observations essential to the calibration or data reduction of instruments on NASA missions, e.g. calibration of JWST spectrometers using the spectra of astrophysical objects.

The TAC evaluates the science of each Mission Support proposal along with the general proposal pool without special consideration for programmatic impact. However, mission support proposals usually garner high strategic grades, and the NASA Keck selecting official, the NExScI Executive Director, will take the TAC evaluation and programmatic concerns into consideration in making the final time assignments.

All proposals submitted under the general mission support category must include the following two endorsement letters; omission of either letter will eliminate a proposal from consideration in the mission support category. The program scientist at NASA Headquarters for the supported mission uses the above criteria to determine whether a letter from NASA Headquarters will be issued.

  1. A written endorsement for the current semester from NASA Headquarters requested by March 3, 2022 from the Keck Program Scientist, Dr. Hashima Hasan ( If you do not hear back from Dr. Hasan after your contact her, we encourage to follow-up to learn the status of your request.
  2. A current, written justification from the flight project requested by March 3, 2022 from the Project Scientist, Project Manager, or Principal Investigator, which includes an explanation of the criticality, strategic importance, and timeliness of the proposed observations. Note that a letter writer cannot be a PI/Co-I on another Mission Support or KSMS proposal in the same semester.

Since the strong support of your letter writers is critical to deciding whether your proposal meets Mission Support criteria, contact the relevant flight project lead and Dr. Hasan at NASA HQ by March 3 to give them time to prepare these letters well before the proposal submission deadline. These letters and your proposal are all due by March 17 and should be uploaded on the submission site.

III. Multi-Semester Proposals and Applying for Partial Nights

Principal investigators may submit general observing/mission support proposals that span up to 4 semesters. Time allocations beyond 2022B depend upon the successful renewal of the NASA-Keck Cooperative Agreement Notice (CAN) in mid-late 2022.

The option of multi-semester proposals reduces the workload on both PIs and the NASA Keck TAC for long-term programs. The NASA Keck TAC will be instructed to consider these proposals in light of all of the criteria that apply for single semester proposals, in addition to the following considerations:

  • If the proposal were accepted for only a single semester, what is the likelihood that it would be accepted again in ensuing semesters?
  • How much observing time does the TAC consider appropriate to remove from consideration in upcoming semesters?

In considering multi-semester proposals, the TAC may recommend accepting the proposal in its entirety, for some subset of the proposed semesters, or reject it outright.

Proposals requesting less than full nights or cadence/Time Domain Astronomy programs must be scientifically and technically justified and can ordinarily be accommodated only if they can be combined with another selected program requiring a compatible instrument and configuration. Observing modes that require substantial observatory support (e.g., Laser Guide Star) are more difficult to schedule as partial night observations.

Programs requesting less than ½ night increments are difficult to schedule and may, in fact, not be schedulable due to the following WMKO requirements: less than ½ night increments must be matched with other compatible NASA programs to fill a full night, and no more than 2 observing programs can be scheduled per night. For example, a ¼ night NASA program must be matched with a compatible ¾ night NASA program.

The Subaru facility prefers full night allocations, although it is usually possible to arrange half night increments. Smaller increments or queue scheduled observations are not permitted.

IV. Target of Opportunity, Cadence, and Twilight Observing Proposals

Please read the following policies with more details below for NASA Keck time specifically. Subuaru time is not available for these types of observations.

IVa. Target of Opportunity Proposals

Due to their disruptive nature, ToO or TDA proposals must be of the highest scientific and/or strategic importance. We will try to schedule the highest priority programs, but cannot guarantee availability of ToO/TDA observations for all approved programs. Observing modes that require substantial observatory support, e.g. LGS, are more difficult to schedule as ToO observations.

ToOs will be limited to instruments currently in use and must be triggered prior to 4:00 pm HST. All ToO observing teams should set up "at-home" observing at the beginning of the semester, well ahead of any possible ToO trigger events.

Partner Interrupts vs. NASA interrupts: ToOs can be requested as "NASA-only" or "Partner." The four major Keck partners (UC, Caltech, UH, and NASA) have agreed that TAC-approved ToO and TDA projects may interrupt observers at any of these four institutions. The NASA Keck TAC can only allocate up to a total/combination of 6 "Partner" cadence interrupts and ToO triggers per semester, i.e. NASA observers can only interrupt observers from any of the other institutions a total of 6 times per semester. Each interrupt cannot exceed 1 hour.

NASA-only ToOs can only be triggered for times when a NASA PI is observing. The limit on the number of NASA-only triggers is dependent on the number and nature of fractional night NASA programs recommended per semester, and will therefore vary each semester, but will likely be no more than 6.

Under the ToO rules, ALL programs, even partial night programs, are designated interruptible by default. PIs may ask for their time to be designated as uninterruptible, i.e. as exempt from ToO or cadence interrupts. To do this, mark the appropriate box on the NExScI submission page and justify in a brief paragraph why the proposed observations cannot be interrupted. This explanation should be strong and scientifically motivated. It is anticipated that interruption-free time will rarely be granted.

Only proposals that fit the case of a ToO observation of an extraordinary opportunity that could not have been anticipated prior to the proposal deadline may be submitted outside of the regular submission cycle to Dr. Dawn Gelino. Note that all ToO proposals must meet the strategic relevance guidelines described above.

IVb. Cadence Proposals

NASA observers can also propose for cadence/Time Domain Astronomy (TDA) and Target of Opportunity (ToO) observing programs. ToO proposals for events likely to happen during a single semester (e.g. gamma-ray bursts, supernovae) must be submitted during the regular submission cycle so that the proposed observations can be considered by the TAC and potential scheduling opportunities can be discussed. Cadence/TDA observations are those that can be scheduled in advance and require only a small fraction of a night several times over a semester. Programs requesting date-specific observations should be submitted as 'specific' proposals noting the date restrictions, NOT as cadence proposals.

IVc. Twilight Observing Proposals

Keck has a program for acquiring snapshot observations in morning twilight. Each partner institution is limited to one twilight program per instrument (currently NIRC2 and OSIRIS) per semester. This program is designed to accommodate extra infrared observations during normally scheduled visible observations, when those observers end early and surrender the last portion of the night. Each partner institution will be limited to one (1) program per partner institution. Programs designed for longer term (> 1-2 years) will be given priority.

The guiding principles of the twilight observing program are:

  • Voluntary participation by classically-scheduled PI and Observing Assistant (OA),
  • Execution completely at the discretion of the classically-scheduled PI and the OA

Furthermore, each approved morning twilight PI is required to:

  • Use only NIRC2-NGS on Keck II and/or OSIRIS on Keck I;
  • develop target and observation managers;
  • develop, test, and debug instrument scripts;
  • employ only simple instrument configurations; and
  • dissect the observations into short integrations (<5min)

Interested PI's should propose using the "cadence" option on the cover sheet. Once a program is approved, the observing team will need to develop a set of instructions, planning tools, instrument scripts for OAs to conduct the observations autonomously. These are voluntary observations by the OA when the classically-scheduled PI volunteers the morning twilight; there is no guarantee on the number of observations that will be conducted. Nevertheless, this program has proven to be advantageous for a certain types of quick snapshot observations.

V. Periods of Exclusive Data Use

Data taken with all instruments on the Keck telescopes are included in the Keck Observatory Archive (KOA) with a default 18-month period of exclusive use. Requests for extensions of this 18-month period MUST be included in the proposal and on the WMKO cover sheet and be scientifically justified. All extensions must be approved by the NASA selecting official.

VI. Publication Acknowledgement

All publications based on data acquired with the Keck telescopes and/or the Keck Observatory Archive must include the acknowledgement(s) below.

Please send a citation for any paper using either acknowledgement to the NASA Keck Operations Scientist, Dr. Dawn Gelino (

WMKO Acknowledgement

"This work was supported by a NASA Keck PI Data Award, administered by the NASA Exoplanet Science Institute. Data presented herein were obtained at the W. M. Keck Observatory from telescope time allocated to the National Aeronautics and Space Administration through the agency's scientific partnership with the California Institute of Technology and the University of California. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain."

KOA Acknowledgement

"This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with the National Aeronautics and Space Administration." Please also use the ADS bibcode provided by KOA to reference the PI of the dataset.

VII. Remote Observing

Special Note on COVID At-Home ("pajama mode") Observing: During the pandemic, Keck will support up to two observers for at-home observing: one primary and one secondary observer. Additional observers can join but cannot launch the VNC control system for the instruments. At-home observing requires the installation of software which only runs on linux and macOS operating systems. At-home observers will be contacted by Keck staff and should work with this staff to install and test the software several days ahead of their run to allow time for troubleshooting. Although first time Keck observers are strongly encouraged to travel to WMKO, due to the pandemic this is not an absolute requirement and first time users may observe remotely via pajama mode.

NASA Keck observers typically have direct access to three Remote Observing Facilities (ROFs) for their Keck observations. These ROFs are located at Caltech (Pasadena, CA), Yale University (New Haven, CT) and USRA (Columbia, MD). See the ROF page for more information and usage guidelines. The procedure to use one of these ROFs should be started no later than 5 weeks before the scheduled nights.

Other ROFs are available to NASA users with direct access to these facilities.

Web Curator and NExScI Cognizant Official: Dr. Dawn Gelino

(last updated February 17th, 2022 11:45:38)