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Hubble Space Telescope

Cycle 25 Peer Review Guidelines

UV Initiative Proposals: How are they Handled?

The Ultraviolet (UV) Initiative that was introduced in Cycle 21 is being continued to ensure the unique UV capabilities of Hubble are fully utilized while they still exist. This Initiative will use orbit allocation targets to increase the share of primary GO observing time dedicated to UV observations (wavelengths < 3200 Angstroms). Small, Medium, Large, and Treasury GO proposals are all eligible, as are UV-themed Regular Archival, Legacy Archival, and Theory proposals. The UV Initiative does not apply to SNAP proposals. The targets are as follows:

These allocations are advisory, not quotas, and UV proposals recommended for acceptance must meet the usual requirement of high scientific quality set for all successful Hubble proposals. However, the panels should use these guidelines when creating their final ranked list. When doing preliminary grades, we suggest that reviewers base their grade on the science.

UV Initiative proposals are marked by the proposers on their cover page. Not all pure UV proposals had been marked by the proposers, so we have flagged them in the Phase I database as UV proposals. Proposals that only request UV observations clearly fall under the Initiative. For proposals requesting both UV and optical/IR observations, the scientific necessity for the UV observations must be carefully justified in the Special Requirements section of the proposal. The reviewers must judge whether this justification is reasonable in order for the UV Initiative benefit to apply.

A list of the HST observing modes covered under the UV Initiative is available here:

In order for Archival Proposals to benefit from the UV Initiative, they should lead to UV high-level data products and tools for the Hubble archive, and enable broader use of those datasets by the community, or (in the case of Theory proposals) provide new models or theories to aid in the interpretation of UV HST data. For Archival Programs that propose the joint analysis of UV and optical/IR datasets, the UV datasets must be essential to the scientific investigation for the UV Initiative benefit to apply.