Hubble Space Telescope Call for Proposals for Cycle 11

3.2 General Observer (GO) Proposals

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A GO proposal may be submitted for any amount of HST observing time, counted in terms of HST orbits. Chapter 6 of the HST Primer describes how the required number of orbits can be calculated for a particular set of observations. Programs that require fewer than 100 orbits are called Regular Programs (see Section 3.2.1), and those that require 100 or more orbits are called Large Programs (see Section 3.2.2). Programs in these categories can request observing time in future cycles when this is scientifically justified (see Section 3.2.3).

The Space Telescope Advisory Committee (STAC) has advocated that a mix of programs of different sizes makes the best scientific use of HST, and that acceptance of Large Programs should be particularly encouraged. The proposal review process (see Section 6.1) was designed to ensure that a reasonable distribution of program sizes is indeed selected. Nonetheless, neither the Regular nor the Large Program category may fully stimulate the type of ambiguous and innovative proposals that could use the full potential of HST in its second decade of operations. STScI is therefore starting in Cycle 11 the new category of Treasury Programs (see Section 3.2.4).

Proposers are strongly encouraged to develop competitive Large and Treasury proposals.

These programs will be evaluated by the TAC (see Section 6.1.2), which can award a total of up to 1200 orbits to proposals in these categories (approximately 1/3 of the total time anticipated to be available in Cycle 11).

3.2.1 Regular GO Programs

Regular GO Programs are programs that request 99 orbits or less.

In recent cycles the acceptance rate of submitted programs has been approximately independent of size. Also, orbit trimming does not usually occur, and proposals are either accepted or rejected in their entirety. Accordingly, you are urged to request the actual number of orbits required to achieve your science goals.

3.2.2 Large GO Programs

Large GO Programs are programs that request 100 orbits or more.

Large programs should lead to a clear advance in our understanding in an important area of astronomy. They must use the unique capabilities of HST to address scientific questions in a comprehensive approach that is not possible in smaller time allocations. Selection of a Large Program for implementation does not rule out acceptance of smaller projects to do similar science, but target duplication and overall program balance will be considered.

The goal in Cycle 11 is to select several programs in the 100-300 orbit range. For comparison, in Cycle 10 seven large programs were accepted for a total of 547 primary orbits and 398 pure parallel orbits. In Cycle 9 six large programs were accepted for a total of 534 primary orbits and 1200 pure parallel orbits.

3.2.3 Long-Term GO Programs

Regular and Large GO Programs may request HST observing time for more than one cycle.

Long-Term Proposals must be limited to cases where it is clearly required to optimize the scientific return of the project.

Long-term programs require a long time baseline, but not necessarily a large number of HST orbits, in order to achieve their science goals. Examples include astrometric observations or long-term monitoring of variable stars or active galactic nuclei.

You may request time in as many as three observing cycles (i.e., Cycles 11, 12 and 13), but you cannot request instruments other than those presently offered in Cycle 11. Long-term proposals should describe the entire requested program and provide a cycle-by-cycle breakdown of the number of orbits requested. The scientific justification for allocating time beyond Cycle 11 should be presented in detail. For long-term programs, it is the sum of all orbits requested for Cycles 11, 12 and 13 that determines whether the program is Large or Regular.

The Cycle 11 Review Panels and TAC will be able to award limited amounts of time to Long-Term Programs for Cycles 12 and 13. GOs with approved Long-Term Programs need not submit continuation proposals in the subsequent Cycles (and hence, GOs who had Cycle 11 time approved in Cycles 9 or 10 do not have to submit a Phase I continuation proposal, although a new Phase II will be required).

3.2.4 Treasury GO Programs

Starting with Cycle 11, we are expanding the opportunities for large-scale research with the introduction of the Hubble Treasury Program. The Treasury program will allow proposals for datasets of lasting value to the HST program that should be obtained before HST ceases operations. Similar to the SIRTF Legacy Program, Treasury Programs will generate public datasets with the potential to address multiple scientific problems. The proposals may include the production of public data products, such as catalogs, with appropriate support under the HST grants program.

The emphasis in Cycle 11 will be on observations whose value will be maximal if taken soon. The on-orbit degradation of CCD detectors, anticipated to be the case for ACS, means that deep observations with ACS will be of most value when obtained early in its lifetime.

A Treasury Program is defined by the following characteristics:

• The project should focus on the potential to solve multiple scientific problems with a single, coherent dataset. It should enable a variety of compelling scientific investigations.
• Enhanced data products are desirable to add value to the data. Examples are reduced images, object catalogs, or collaborative observations on other facilities (for which funding can be provided). Funding for the proposed data products will depend on their timely availability, as negotiated with the STScI Director. They should be delivered to STScI in suitable digital formats for further dissemination via the HST Data Archive or related channels.
• Data taken under the Treasury program will have no proprietary period (see Section 5.1), although brief proprietary periods may be requested, if they will enhance the public data value.

The following additional characteristics are particularly encouraged:

• Development of new techniques for observing or data reduction.
• Creation and dissemination of tools (software, web interfaces, models, etc.) for the scientific community to work with the data products.
• An Education/Public Outreach component.

Treasury programs may request observing time to be distributed in future cycles with appropriate justification (similar to the situation for Regular and Large GO programs; see Section 3.2.3). In addition, Treasury programs may request observing time in future cycles if the requested number of orbits is large enough to make implementation in a single cycle impractical or impossible.

Approximately 30% of the available HST observing time in upcoming cycles (up to approximately 1200 orbits per cycle) will be devoted to the combination of Large programs and Treasury Programs. As a result:

It is feasible and encouraged to think of a multi-cycle Treasury Program of order 1,000 orbits over several cycles, with commensurate funding to produce an enhanced dataset of high impact.

Selection of Treasury Programs will be handled by the TAC as part of the normal peer review process (see Section 6.1.2). Successful proposals will be reviewed by STScI to ensure observing efficiency. Multi-cycle programs will be reviewed annually by STScI for continuance to ensure that adequate progress is being made to achieve the goals of the project. STScI resources may be made available to approved Treasury Programs by decision of the STScI Director.

Those interested in submitting a Treasury Proposal are encouraged to read the Hubble Second Decade Committee Treasury Program Report. Although some recommendations of the committee were implemented differently than suggested, the report sets out the main motivations for the Treasury Program.

Treasury Proposals should be identified with the `treasury' keyword in the `Special Proposal Types' section of the proposal (see Section 8.11).

The `Scientific Justification' section of the proposal (see Section 8.15) should include a description of the scientific investigations that will be enabled by the final data products, and their importance. The `Description of the Observations' section of the proposal (see Section 8.16) should not only describe the proposed observations and plans for data analysis, but should also describe the data products that will be made available to STScI and the community, the method of dissemination, and a realistic time line.