Special policies apply to cases in which a proposed observation would duplicate another observation already obtained with HST, or currently in the pool of accepted HST programs.
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.
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 have imaging capabilities superior to WFPC2, NICMOS and STIS for many purposes (see
Section 4.8 of the 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.
Under NASA policy, GTO programs (see Section 3.9)
are protected against duplication by GOs. Proposed GO observations that are judged to infringe upon this protection will be disallowed. However, the duplication protection is as specifically defined above; entire classes of objects or broad science programs are not protected. The COS GTO program is described at
http://www.stsci.edu/hst/proposing/docs/COS-GTO.
The GTOs are entitled to revise their programs after each cycle of GO selection, but they in turn may not duplicate previously approved GO programs. GTOs may not modify their programs in the time interval between the publication of the GTO/GO catalog in each cycle and the final submission of the Phase II GO programs selected for that cycle. The protection of each observation is in force throughout its proprietary data-rights period (see
Section 5.1) and then expires.
Occasionally it may happen that a proposer requests an early-acquisition image (see
Section 5.2.1 of the HST Primer) that is already in a GTO program, and would be protected according to the NASA policies outlined above. If an early-acquisition image is determined to be in conflict with a protected GTO image, then the GO-requested image may still be permitted, but may be used only for acquisition purposes.
To check for duplications among the observations that you wish to propose, please use the tools and links on the
HST Proposal Support Web Page at MAST. The following two options are available:
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.
