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The Large and Long Program Proposal Process

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This page describes the general Large and Long Program (LLP) proposal process. Additional details pertaining to a specific call for proposals can be found on the current Call for Proposals.


Letters of Intent

Letters of Intent to propose a LLP must be received by email to by 23:59 Hawaii–Aleutian Standard Time (GMT-10), February 4, 2020. Letters should include the information below, formatted as follows.

  • Title of Project
  • PI with full name of institution and contact information (phone and email)
  • Co-Is with full names of institution
  • Broad scientific overview of the program (500 word limit)

The Letters of Intent are intended to allow for the selection of the allocation committee with minimal conflict of interest and applicable scientific expertise. Secondly, the description of the proposal program will allow for a review of the program in light of technical and operational constraints. Please keep this in mind when composing a Letter of Intent to ensure that relevant material is included.


Proposals for LLPs are due April 7, 2020, 23:59 HST (Hawaii-Aleutian Standard Time) . Investigators must use the Gemini Phase I Tool for creating and submitting LLP proposals. A new Phase I Tool (PIT) is released each semester. Information on how to download and install the Tool is given on the semester's installation page. Help on the PIT is available via the PIT help page and video tutorials. Information on target restrictions, instrument availability, and time availability is given in the current LLP Call For Proposals.

The proposal narrative is submitted as a pdf attachment to the PIT. Latex and Word templates will be available as part of the 2020B Call for Proposals to create the pdf attachment. The proposal narrative must include:

  • a discussion of the primary scientific justification of the project;
  • a description of the experimental design, including sample selection, scheduling requirements, calibration, etc.;
  • a statement of the time requested each semester, including required instruments and observing conditions in the technical case.;
  • a description of the mode of observation (see below) and explanation of required mode for classical and fully queue mode requests;
  • a management plan that describes staffing and resources available to complete the science program and the expected contributions of each participant; This section should include the data management plan, including resources needed to meet the processed data requirement.
  • a discussion on added value to Gemini Observatory and the broader astronomical communities through the public release of data products, catalogs, software, public outreach, or other outcomes beyond the proposed science results;
  • Program considerations if allocated in band 2, included in the experimental design;
  • Supplemental proposal information, such as previous time allocations, relevant PI publications, etc;
  • An estimate of the distribution of targets and time allocation throughout the lifetime of the proposed LLP;
  • Sample, relevant Integration Time Calculator (ITC) output supporting time request.

Other required information, entered directly into the PIT:

  • title, abstract, TAC category, keywords, and the investigators' names and institutions;
  • a list of targets, observing conditions, and instrument configurations for the 2020B semester request;
  • Scheduling constraints if there are time-critical or synchronous observations involved, or impossible dates for classical programs in the 2020B semester.

The proposal narrative is limited to a total of 10 pages, and the science justification cannot exceed 5 pages, including figures and references. The page limit does not include ITC attachments or the distribution of targets table.

Proposal Evaluation and Acceptance

A separate Large Program Time Allocation Committee (LPTAC) will evaluate the submitted LLP proposals, assessing them for scientific excellence and program feasibility, including program management. While membership in the LPTAC is selected, in part, to provide expertise on the science cases as indicated in the Letters of Intent, LLP proposal science justifications should be intelligible to a broad audience. The LPTAC will base their evaluations of proposals on the criteria listed here in descending order of importance.

  1. The overall scientific merit of the proposed investigation and its potential contribution to the advancement of scientific knowledge.
  2. The technical feasibility of the proposed observations.
  3. The ability of the proposing team to carry out the proposed research to a successful conclusion within the proposed timeframe, as established by the management plan.
  4. Added value to the Gemini and broader astronomical communities beyond LLP team science results, as demonstrated by the planned public release of reduced data products, catalogs, software, public outreach, or other outcomes.
  5. The extent to which the observations can be accommodated within routine Gemini operations and the extent to which the overall science program enables an efficient use of the observatory.

Following the LPTAC process, the LPTAC sends their recommendations to Gemini Observatory. While most proposals recommended by the TAC are allocated time, additional operational and scheduling constraints can prevent high-ranking programs from being awarded time. Successful LLPs will have the equivalent of either Band 1 or band 2 status. In general, a LLP will have the same band status throughout the lifetime of the LLP. However, some programs may have their allocations moved between band during the life of the LLP due to operational and time allocation constraints. Programs are made aware of the expected band status when the initial allocation is awarded. These bands have the same meaning and expectations of completion as regular queue programs. Successful and unsuccessful LLP proposal PIs will receive LPTAC feedback and scoring information after the LPTAC and telescope scheduling process.

The membership of the previous LPTAC is available on the Gemini Committees web page.

Time Allocations

LLPs can have allocations spanning more than a single semester and an expected amount of time allocated within a given semester. Each semester, during the ITAC process, LLPs expected allocations are required to be merged with regular queue programs, classical requests, limited-term partnerships, etc., in the telescope scheduling process. Some changes to semester allocations may result from this merge process.

LLP programs do not have rollover status. Although a program may continue from one semester into the next, any remaining time on the program from the previous semester will be lost. The PI can request adjustments through their annual reporting cycle, but for our operational purposes time is not carried over semester boundaries and the program will commence with the "fresh" allocation of time at the start of each semester. Although time does not carry forward over a semester boundary, PIs can choose to execute observations not completed in the previous semester, "paid for" from their time allocation in the current semester.

Observing Modes

The Large Program PIs and Co-Is are encouraged to visit Gemini a) for Gemini to learn from them and to optimally support them, b) for them to learn about Gemini operations in order to optimally plan their observations and their data reduction, whatever mode of observation they are using.

Three modes of observations are available to LLPs:

Priority visiting observing : The PI or team member comes to Gemini, prepared to observe either their own program if the conditions are sufficiently good, or to execute approved queue programs if the conditions are too poor for the LLP. The LLP will be charged only for time devoted to the program, and additional observations may be made by Gemini staff or other observers of the queue during the semester. (See the PV Mode Definition page for more information).

Queue: LLP observations are executed only as part of the regular queue, observed by Gemini staff or other observers. Queue mode must be justified, requiring infrequent conditions or monitoring on an infrequent basis, for example. LLPs allocated time in Band 2 will default to Queue mode observing.

Classical: The program is scheduled on specific dates, and the PI or a team member comes to Gemini to observe that program on those dates, accepting the variability of weather.

Priority visiting observing will be the default mode for Band 1 scheduled LLPs. LLPs scheduled into Band 2 will default to queue mode observing.

The LLP PI must certify that classical and priority visiting observers have sufficient observing experience to execute the program. Gemini staff will not provide basic training about observing techniques.

Gemini Observatory Participants