Phase I 2024B call for proposals for Canadian access to Gemini

The Gemini Observatory has issued the call for proposals under the standard semester program for semester 2024B, which runs from August 1, 2024, to January 31, 2025. For full details of the call for proposals and each instrument available, consult the current Gemini call for proposals. For information on previous calls for proposals, consult the list of previous Gemini semesters.


Deadline for Canadian proposals: 4 pm (Pacific Daylight Time) on Tuesday, April 2, 2024

Deadline for joint proposals (international collaborations): Use the deadline for the country the principal investigator is affiliated with. For additional information, consult Gemini joint proposals.

Note: Consider relaxing your program's observing constraints to be suitable for Band 3, even if your program will take longer to execute to achieve the desired signal-to-noise results.


For principal investigator programs in semester 2024B, Canada will have access to a total of 161 hours at Gemini North and 163 hours at Gemini South. For information on the individual instruments, consult the list of current instruments and the current instrument configurations. For updated information on availability of instruments at both sites and instrument fact sheets, consult the Gemini instrumentation page. Also, before beginning your proposal, be sure to consult the What's new this semester section of this page.

  • Facility instruments available at Gemini North
    • GMOS North, GNIRS including the new low-resolution mode IFU and high-resolution mode IFU (on a shared-risk basis)and acquisition "keyhole" for imaging (NIFS and NIRI are no-longer available)
    • Altair is anticipated to be available in Natural Guide Star (NGS) and Laser Guide Star, including LGS+P1 mode, subject to diagnosis of current technical issues. Prospective Altair users should consult the status updates on the Gemini instrumentation webpages
  • Visiting instruments available at Gemini North (subject to demand)
    • 'Alopeke, MAROON-X and TEXES
  • Facility instruments available at Gemini South
    • GMOS South, Flamingos-2 (imaging, long-slit and MOS modes) throughout the semester, and GSAOI with GeMs in two or three runs of 7 nights each
    • GHOST will be offered throughout the semester
  • Visiting instruments available at Gemini South
    • Zorro (subject to demand)

We recommend you review the information on instrument restrictions and target accessibility for the current semester.


Use the Gemini Observatory Phase I Tool (PIT) and PIT templates to prepare and submit your proposal. You can download the latest version of the tool and get installation instructions, release notes and information on known bugs from the PIT Phase I main page.

  • Anonymized proposal: Prepare your proposal following the requirements for a dual anonymous review process (DARP), which is followed by ranking by the Canadian Time Allocation Committee (CanTAC). Consult the NRC guidelines for writing DARP proposals.
  • Proposal attachments: Include the required 2 PDF attachments with your proposal (team information and proposal information), created using the proposal templates. An experimental design section has been added to the proposal information document to provide you with more space for your proposal description. We strongly encourage you to also include the Instrument Time Calculator output in the PDF file.

Proposal templates: Use either the LaTeX or the Word template to prepare your PDF attachments for the scientific justification, experimental design and technical description. Be sure to follow the instructions included in the template.You can download the templates from the Gemini PIT webpage.

  • Page limits: Proposals must not exceed the maximum number of pages or they will be rejected:
    • Scientific justification: 1 page (excluding references)
    • Experimental design: 1 page
    • Technical description: 1 page
    • References, figures (up to 3, with captions): 2 pages maximum
  • Changes to PIT: We recommend you give yourself extra time to become familiar with any recent changes to the PIT. For a description of the proposal sections and other helpful information, including video tutorials, consult the help page for the Gemini PIT.
  • Requesting time at both North and South: If you are requesting time at both Gemini North and Gemini South, you no longer need to submit a separate proposal for both. However, you must indicate in the technical description section of your proposal how much time you are requesting at Gemini North and Gemini South.
  • Submitting final proposal: After you submit your final proposal in the PIT, it is sent electronically to Gemini and then retrieved by the Canadian Gemini Office, which is in charge of the technical assessment of the proposals.
  • Data proprietary period: All data are subject to Gemini's 12‑month proprietary period.
  • Confirmation of submission: You will not receive a confirmation email or notification after submitting your proposal. If your proposal was successfully submitted, the status in the Submit tab will change to Successfully Received and a reference number will appear (e.g. CA-2024A-003).
    • Important: If you do not see the reference number, send an email to to confirm whether your proposal has been received.

What's new this semester

  • General target limitations
    • Gemini North:
      • 17h < RA < 13.5 h
      • -37° < dec < +90°
    • Gemini South:
      • 16h < RA < 12h
      • -90° < dec < +28°

For RA restrictions for specific instruments, consult instrument restrictions and target accessibility for the current semester.

  • Gemini North - GNIRS HR IFU: The new GNIRS High Resolution IFU will be available for shared-risk observations during semester 2024B.
  • Gemini Observatory currently operates a Graduate Student Visitor Program, which will be offered to successful 2024B proposals. Details of this are available from the Gemini CfP webpage.
  • GMOS North now offers the B480 grating, but B600 is not available in semester 2024B; R600 is available only in classical mode (consult the grating information on the Gemini components page)
  • Planned engineering shutdown for Gemini North and Gemini South (dates subject to change)
    • Gemini North: expected to be closed for 12 nights engineering 14-25 October, and 1-3 nights in September (TBD)
    • Gemini South: expected to be closed9 nights at the start of semester 2024B, 1-9 August
  • Visiting instruments available at Gemini North
    • 'Alopeke imager: a fast low-noise, dual-channel and dual-plate-scale speckle imager that provides both diffraction-limited and wide-field imaging
      • Target of Opportunity (rapid or standard) requests are accepted for 'Alopeke but will be executed only during the instrument blocks.
    • MAROON-X: a high-resolution (R~80,000) optical radial velocity spectrometer
      • The instrument has demonstrated sub-m/s on-sky precision for RV measurements of M dwarfs.
    • TEXES: a high resolution (R ~ 4,000-100,000) mid-infrared (4.5-25 micron) spectrometer; available in semester 2024B, subject to demand.
  • Visiting instruments available at Gemini South
    • Zorro: an 'Alopeke clone
      • Target of Opportunity (rapid or standard) requests are accepted for Zorro but will be executed only during the instrument blocks.
  • Subaru communities
    • There will be a minimum of 5 nights available on Subaru. Instruments available:
      • AO188 (LGS-AO with a shared-risk policy, and NIR-WFS, in limited modes, although principal investigators must contact the NIR-WFS PI, and include him in the proposal as Co-I)
      • FOCAS
      • HDS
      • IRCS (with NGS AO capability) and IRCS/SCExAO polarimetry mode available (also in shared-risk mode, accessible via collaboration with the waveplate PI)
      • MOIRCS
      • Hyper Suprime-Cam (HSC) in queue mode (new filters available, but principal investigators must obtain prior approval for their use)
      • Note that the windscreen of the Subaru telescope is out of operation in 2024B, and thus tracking of targets may not be possible in high winds. It is recommended that PIs have targets across a range of RAs so that different azimuth angles are available.

If you apply for time through the Gemini time-exchange program, explicitly note if you are also submitting a duplicate request through the Keck time-exchange program or the Subaru call for the same program. For semester 2024A, Gemini users can request no more than 3.5 nights (35 hours science time including overhead) in the case of HSC queue, and no more than 5.0 nights in the case of HSC classical requests.

Subaru will also now accept shorter programs (less than 4 hours) for Subaru's Service mode for IRCS, HDS, FOCAS or MOIRCS (imaging). Indicate if you are requesting regular time (half night or full night) or service time (4 hours maximum including calibrations and overheads).

  • Visiting instruments available (proposals must include the relevant principal investigator as a co-investigator)
    • SCExAO, including the VAMPIRES module
    • CHARIS
    • IRD infrared doppler, an infrared, high-resolution (up to 70,000) fibre-fed spectrometer (as long as the targets are different from the approved SSP program)
    • REACH (IRD+SCExAO+AO188)
    • MEC (in shared-risk mode)
    • Fast PDI (in shared-risk mode)
    • NsIR waveplate unit
    • NIR-WFS: Near Infrared Wavefront Sensor. Located inside the AO188 instead of the visible curvature wavefront sensor of AO188 for SCExAO and IRCS


  • Anonymized proposals: All Gemini proposals, without exception, now undergo a dual anonymous review process and must be anonymized. Consult the NRC guidelines for writing DARP proposals.
  • AEON: The PIT now includes an option to specify in the Time Requests tab that the proposal is part of an AEON multi-telescope facility system proposal, which requires that a separate proposal be sent to NOIRLab for the time requested on Las Cumbres and/or SOAR.
  • JWST synergies: The PIT now includes an option to specify in the Time Requests tab that the proposal has synergies with James Webb Space Telescope observations (JWST proposal category). This is to encourage development of science programs that would benefit from a combination of Gemini and JWST observations. It is not necessary for JWST observations to have already been approved in order to submit a proposal in this category. Describe the science goals of the full Gemini and JWST program in the scientific justification section and the combined Gemini and JWST observation program in the experimental design section.
  • Time calculation for baseline calibrations: The PIT will automatically calculate the required time for baseline calibrations and add it to the time request. For each target you get from the Integration Time Calculator, enter the on-source exposure time needed with overheads (acquisition time, readout time, etc.). The PIT will calculate the total time needed for the target.
  • Gender statistics: Gemini would like to collect statistics on gender to measure and monitor gender equality across submitted and successful proposals. As a result, you are kindly asked to fill in the gender field in the investigator details section of the PIT. This information is not transmitted to CanTAC.
  • Classical and Priority Visitor modes: Classical mode observing is offered only for facility instruments. Priority Visitor mode is offered at both Gemini North and Gemini South. Remote Eavesdropping mode is encouraged for all queue programs.
  • Target of Opportunity follow-ups: For all proposals for Rapid Target of Opportunity (RToO) follow-up, a separate proposal must be submitted for Standard Target of Opportunity (SToO) follow-up with observing conditions better than SB/CC/IQ=Any, if such follow-up is planned.
  • Submission of poor weather, Director's Discretionary Time and Fast Turnaround proposals: Poor weather and Director's Discretionary Time proposals can now be submitted directly to Gemini at any time via the PIT, bypassing CanTAC. Fast Turnaround proposals can be submitted at any time (deadline is the end of every month).