25B-26A Filler Time

Special Call for GBT 25B-26A Filler Time Proposals

The Green Bank Observatory (GBO) invites the scientific community to submit Special Call proposals for filler-time observations on the Green Bank Telescope (GBT) during the 25B and 26A semesters. Approved projects will be conducted through July 31, 2026.

Submission Deadline:
Friday, November 28, 2025, at 22:00 UTC (17:00 Eastern Time)

Proposal Guidelines

  • Weather Conditions:
    Observations will be scheduled without consideration of the weather conditions.
  • Length:
    Proposals are limited to one page of text, with one additional page permitted for figures and references.
  • Priority:
    Accepted proposals will have lower scheduling priority than those approved through the standard Telescope Allocation Committee (TAC) review process.
  • Available Observing Modes:
    Only the following backends may be requested: DCR, VEGAS, and VEGAS pulsar modes. 
    Observations will be restricted to using the 800, L, S, C, and X bands for 25B and 342, 800, L, C, and X bands for 26A. 
    Observations for other backends or receivers will not be considered. Observations are restricted to the 20-14 hour LST range. 
  • Execution:
    All observations will be conducted by GBO staff using standard and well-established observing modes.
    Proposals requiring complex setups or non-standard observing strategies will not be considered.
  • Restrictions:
    • Proposals that were previously submitted and reviewed during the 25B or 26A TAC cycles are ineligible.
    • Large Proposal submissions are not permitted under this call.

Submission Instructions

All proposals must be submitted through the Proposal Submission Tool (PST) at https://my.nrao.edu/

When submitting, select “Special Call” as the proposal type in the PST.

Additional Information

Anika Schmiedeke

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