Call for Proposals: UC time on the Keck telescopes

Semester 2019B (Aug 1, 2019 through January 31, 2020)

Deadline: Proposals are due on Monday, March 18thth, 2019 by 5:00 pm PDT

Please read these guidelines carefully, as several things have changed since last semester.

1.0 General Considerations.

1.1 Due Date and Proposal Process

Proposals for UC observing time on the Keck Telescopes for Semester 2019B are due by 5:00 pm on Monday, March 18th, 2019.*

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.

For Semester 2019B, we expect a total of about 63 UC nights on Keck I and about 59 UC nights on Keck II. 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.

1.2 Be Kind to your TAC Members

In the previous semester (2019A) there were numerous proposals which exceeded the page limits for the various proposal subsections. This placed quite a burden on members of the Time Allocation Committees, and gave an unfair advantage to those PIs who exceeded the page limits. Please read the page limits carefully on the keck-guidelines web page ( and adhere to them. For semester 2019B, 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 submitting numerous proposals as real burden on the reviewing process, and that it generally does not increase the odds of a PI getting Keck time. Please use moderation.

1.3 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 Please read these carefully as there are very significant changes from last semester, motivated largely by the need for follow-up of LIGO gravitational wave events. For Semester 2019B, proposals for ToO time and Cadence time will be handled separately.

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 2019B, four Keck partners (UC, Caltech, UH, and NASA) have agreed that TAC- approved ToO (TDA) projects will be 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 of seven Partnership ToO (7) interrupts for UC in 2019B. (Caltech will also have 7; NASA and UH will have 6 each.) 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.

The Keck rules for what types of observing programs can be interrupted have also changed quite a bit. Starting in 2019B, even 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.

1.4 Keck’s new policies for Cadence observations

Keck's new 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.

Please note that the Cadence observing policies now include Twilight Cadence Observing. Each institution may allocate one twilight cadence observing program per semester. See the Keck Cadence guidelines for details.

1.5 Changes to the Technical Remarks Section

Changes made to the Technical Remarks section in 2019A will be continued in semester 2019B. These include page limits and a brief optional, but recommended, section describing your activities in the service of UCO. These changes are described at:

1.6 Large Multi-Year Projects
Large Multi-Year Project (LMAP) programs are UC 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.

2.0 Notes on Instruments and Availability
See the following web page for detailed notes on the availability of instruments for 2019B: There are quite a few notes for individual instrument availability, so please read quite carefully. Instrument descriptions are at Because 2019B instrument availability is fairly complex, we have not tried to summarize it here.

KOA (Keck Observatory Archive): Data from all instruments will be archived in the Keck Observatory Archive (KOA). The default proprietary period for all data is 18 months. If observers desire a different proprietary period they may request this through the Keck coversheet. Please see the KOA homepage: for information on the archive, as well as for information on the KOA proprietary period policy.

Claire Max
Director, UC Observatories
University of California, Santa Cruz
1156 High Street
Santa Cruz CA 95064