HST Call for Proposals for Cycle 21

5.2 Policies and Procedures Regarding Duplications

Special policies apply to cases in which a proposed HST observation would duplicate another observation either already obtained or scheduled to be obtained.

5.2.1 Duplication Policies

ACS and WFC3 Duplications of WFPC2, NICMOS or STIS imaging

Snapshot Targets

An observation is a duplication of another observation if it is on the same astronomical target or field, with the same or a similar instrument, with a similar instrument mode, similar sensitivity, similar spectral resolution and similar spectral range. It is the responsibility of proposers to check their proposed observations against the catalog of previously executed or accepted programs.


	If any duplications exist, they must be identified in the ‘Observation Summary’ section of the proposal (see Section 8.16), and justified strongly in the ‘Justify Duplications’ section of the proposal (see Section 9.5) as meeting significantly different and compelling scientific objectives.

Any unjustified duplications of previously executed or accepted observations that come to the attention of the peer reviewers and/or STScI could lead to rejection during or after the Phase I deliberations. Without an explicit Review Panel or TAC recommendation to retain duplicating exposures, they can be disallowed in Phase II. In such cases, no compensatory observing time will be allowed and the associated observing time will be removed from the allocation.

ACS and WFC3 Duplications of WFPC2, NICMOS or STIS imaging

ACS and WFC3 have imaging capabilities superior to WFPC2, NICMOS and STIS for many purposes (see Section 4.7 of the HST Primer). Nonetheless, proposers should note any duplications of previously approved or executed WFPC2, NICMOS, or STIS imaging exposures that lie in their fields, and justify why the new observations are required to achieve the scientific goals of the project. Proposers for WFC3 observations should note and justify any duplications of previous ACS observations.

Snapshot Targets

The following policies apply to Snapshot targets, in addition to the duplication policies already mentioned:

•	Snapshot targets may not duplicate approved GO programs in the same cycle.

•	Snapshot observations may be proposed that duplicate approved but unexecuted Cycle 20 Snapshot observations by the same Principal Investigator. If the Cycle 21 program is accepted, the Cycle 20 program will not be carried forward into Cycle 21.

5.2.2 How to Check for Duplications

To check for duplications among the observations that you wish to propose, please use the tools and links on the HST Proposal Support Webpage at MAST. The following two options are available:

•	The HST Duplication Checking Web Form.

•

The Planned and Archived Exposures Catalog (PAEC), which is available from the HST Catalogs Webpage at MAST. This catalog contains summary information about exposures in ASCII format and can be browsed with any text editor. It is normally updated monthly, but will be kept fixed between the release of this Call for Proposals and the Phase I deadline.

Please make sure that you are either searching in the HST duplication table (automatic if you use the Duplication Checking Web Form) or the PAEC. Other archive tables, such as the science table or the ASCII format Archived Exposures Catalog (AEC) do not include exposures that have been approved but have not yet executed, and are therefore not suitable for a complete duplication check.