You are here

2023 Call for Large and Long Programs

Content owned by Sandy Leggett


Important Dates

  • December 7, 2022 LLP Proposal Cycle Announcement of Opportunity
  • February 13, 9am HST, 2023 - Letters of Intent Due
  • March 1, 2023 - 2023B regular semester Call for Proposals released
  • April 1, 2023 - 2023 LLP Proposals deadline 
  • Late-April, 2023 - Large Program Time Allocation Committee meets
  • Mid-June, 2023 - 2023B telescope schedule and LLP proposal cycle announcements

This page contains information specific to the 2023 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 time available is estimated as 200 hours less any previously allocated LLP time. 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.

Estimated Time Available for new LLPs in Hours
Site Band 2023B 2024A 2024B 2025A 2025B 2026A
North 1 55.0 100.0 100.0 100.0 100.0 100.0
2 31.0 29.0 100.0 100.0 100.0 100.0
South 1 100.0 100.0 100.0 100.0 100.0 100.0
2 45.5 44.6 100.0 100.0 100.0 100.0

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.

Gemini North

  • GMOS-N: Available for use 2023B-2026A. See special note on GMOS MOS proposals below.
  • GNIRS: Available for use 2023B-2026A,  in imaging (through keyhole), long slit, cross-dispersed and IFU modes. Adaptive optics is expected to be available for all modes. Prospective PIs must check for updates on the IFUs before submitting their full proposal.
  • Altair: Available for use 2023B-2026A.
  • Alopeke: Available for use 2023B-2026A.
  • MAROON-X: Available for use for three semesters only, 2023B-2024B, as the current agreement only extends through 2024B and conversion to a facility instrument is still under study.

Gemini South

  • GMOS-S: Available for use 2023B-2026A. See special note on GMOS MOS proposals below.
  • FLAMINGOS-2: Available for use 2023B-2026A, in imaging, longslit and MOS modes.
  • GSAOI/GEMS: Available for use 2023B-2026A.
  • GHOST: Available for use 2023B-2026A. Prospective PIs must check for updates on this new instrument before submitting their full proposal.
  • Zorro: Available for use 2023B-2026A.
  • IGRINS: Available at Gemini South for use in semester 2023B only, programs are then expected to be converted to IGRINS-2 at Gemini North starting in 24A and continuing through 26A. Target locations should be chosen accordingly.

Visitor Instruments

Gemini Observatory welcomes LLP proposals utilizing visitor instruments. The policy on LLP proposals requesting a visiting instrument is available as part of the Visiting Instrument policy. Any PI, either from the instrument team, or from interested members of the community considering a LLP proposal using a visiting instrument is encouraged to contact Gemini Observatory at prior to Letter of Intent submission to discuss the feasibility of any request.

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 for observations beginning in 2023B. Subaru reserves the right to reject this program if it cannot be reasonably accommodated in the Subaru schedule. Instruments available for new SIP programs starting in 2023 are: FOCAS (optical imaging and longslit and multi-slit spectroscopy), possibly decommissioned before 2026A; Hyper Suprime-Cam large-field imager, limited to 5 or less nights a semester; some PI instruments may also be available for SIP but the instrument teams must be contacted in advance. It is very important that prospective SIP PIs check the Subaru 23A Call for Proposals (issued in early February) before submitting their full proposal.