The 2025 LLP cycle call covers semesters 2025B-2028A. We are currently soliciting Letters of Intent which are due February 14, 2025. Full proposals will be due via the PIT on March 31, 2025.

This page contains information specific to the 2025 Large and Long Program proposal cycle. General information on the LLP proposal process, including proposal format and requirements, can be found on the LLP Proposal Process webpage.

Time Available for New Gemini LLPs

The estimated time available for new Gemini LLPs is provided in the table below. The numbers in the Table are estimates only, the exact time available will depend on instrument commissioning, engineering, campaign science, limited-term partnerships, etc. as well as the status of ongoing LLP programs. Please note the limited Band 1 hours at Gemini-N for 25B and 26A.

* We are not offering Band 1 for Gemini-S in the 2025 LLP call, but expect it to be offered in the 2026 LLP call.

Target and Observing Constraint Restrictions

An individual LLP need not request a balanced program across North/South, RA range, observing conditions, etc. However, the ensemble of approved LLPs must not overly impinge on other observing programs. Therefore, the ensemble of approved LPs should not exceed ~25% of any relevant parameter, such as hemisphere, RA range, and observing condition bins. See this page for further information on observing condition constraints.

LLPs will also be subject to general semester target availability restrictions, as published in the general call for proposals for each semester.

Instrument Availability

The instruments available for new LLPs are listed below, along with any particular restrictions of note. Successful LLPs may also be limited by the semester-specific instrument availability restrictions announced with each semesters regular Call for Proposals. PLEASE READ CAREFULLY!

Gemini North

• GMOS-N: Expected to be available 2025B-2028A. All modes offered, although Nod and Shuffle may only be available 5 out of the 6 semesters. See special note on GMOS MOS proposals below.
• GNIRS: Expected to be available late 2025B-2028A. All modes offered except for short red camera.
• Altair: Expected to be available 2025B-2027A. Offered for Natural Guide Star (NGS) guiding only.
• Alopeke: Expected to be available five out of six semesters in 2025B-2028A. Block scheduled based on TAC approved demand each semester.
• MAROON-X: Expected to be available 2025B-2028A.
• IGRINS2: Not Available for this call.

Gemini South

• GMOS-S: Expected to be available 2025B-2028A. All modes offered, although Nod and Shuffle may only be available 5 out of the 6 semesters. See special note on GMOS MOS proposals below.
• FLAMINGOS-2: Expected to be available 2025B-2028A. All modes offered.
• GSAOI/GEMS: Expected to be available five out of six semesters 2025B-2028A. Will be block scheduled based on TAC approved demand each semester, with between one and three runs (each up to two weeks long) during a semester.
• GHOST: Expected to be available 2025B-2028A. All modes except for Precision Radial Velocity.
• Zorro: Expected to be available five out of six semesters 2025B-2028A. Block Scheduled based on TAC approved demand each semester.

Special Note for programs proposing to utilize GMOS MOS mode at Gemini North or South

The GMOS instruments can hold 9 masks at any given time. These masks include those required by regular programs, which may need to be installed for lengthy periods if monitoring is required or if the observation time is large. For these reasons new LLP programs should limit the number of masks needed to around 20 masks per site per semester. The number of masks in a given 3-hour RA range must be less than this -  around 5 per semester per site.

Subaru Intensive Programs

PIs from LLP participating partners (currently the US and CA) are invited to submit proposals for Subaru Intensive programs (SIP) to Gemini through the Gemini-Subaru time exchange program. Subaru Intensive programs applications follow the same rules and eligibility used for the Gemini Large and Long Programs (LLPs). The request of Subaru Intensive program must be clearly stated in the title of the proposal. The required Subaru instrument configurations should be specified in the Abstract. At most, one proposal will be selected. It is very important that prospective SIP PIs check the Subaru 25B Call for Proposals (issued in early February) before submitting their full proposal. Note that the PFS large program (Strategic Program) begins S25A which may mean programs requesting many dark nights may not be accomodated.