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/ [1]
When submitting, select “Special Call” as the proposal type in the PST.
Additional Information
- Details on the GBT and its capabilities can be found at:
https://science.nrao.edu/observing/call-for-proposals/2026a/introduction [2] - Results and pressure plots from the 25B and 26A Regular Proposal Calls can be found at:
https://science.nrao.edu/observing/proposal-types/tac-reports/tac-report-page [3]