New and Notable Changes in 2023A

The following announcements are notable for the 2023A semester. Please read through the below carefully. 

Dual Anonymous Review Process adopted by US, Canada, Brazil, and Argentina

  • All Gemini proposals requesting time from the US, CA, BR, or AR must be anonymized. Proposals which do not meet the guidelines will be penalised. This applies to proposals requesting time only from these partners, as well as joint proposals requesting time from multiple participants which include any of these partners. This requirement applies whether it is the PI or a co-I that has the relevant partner affiliation.

2023A Phase 1 template

  • All proposals to use Gemini in 2023A must use the 2023A Phase 1 template. It was revised in 22B to enable the anonymous reviews, and to make proposals requirements, such as page and figure limits, uniform across the partners. Two attachments are required for the proposal so that team information can be separated from the science case.

AEON in PIT and Synergy with JWST

  • Starting in 22B, the Gemini Phase 1 Tool includes an option to specify that the Gemini proposal is part of the Aeon multi-telescope-facility system, and an option to identify proposals which
    have synergies with James Webb Space Telescope observations,
    whether already awarded, or still to be proposed.

Classical and Priority Visitor mode

  • Classical mode observing is NOT offered in semester 2023A. Priority Visitor mode is offered at both Gemini North and Gemini Southhowever if circumstances preclude having people on site, then awarded Priority Visitor time will revert to queue. The "Bring One, Get One" Student Observer Support Program remains unavailable.

B480 grating for GMOS-S available

  • NEW for 2023A - GMOS South is now available with a B480 grating.


  • IGRINS will be available throughout the semester except for two weeks before and during the 7-night GeMS/GSAOI runs. See the IGRINS at Gemini page for important information about writing IGRINS proposals.
  • The KASI IGRINS team were awarded a compensatory time of ~47 hours for this semster from Gemini, and a good fraction of this time will be allocated for the IGRINS proposal from the community.
Call for Proposal for Gemini / 2023A

Observable Targets

  • Targets are generally limited to 
    • NORTH : 4 < RA hours < 1 and -37° < dec < +90° 
    • SOUTH : 5 < RA hours < 1 and -90° < dec < +28° (If an April shutdown for the delayed primary mirror coating occurs, the time available at RAs 9 - 11 will be reduced by about 20%.)
  • There are additional constraints as described in the target accessibility and instrument restrictions page.

Available Hours

  • GN : 90 hours (for this queue/classical program call)
  • GS : 72 hours (for this queue/classical program call)


  • Check out the full availability and restrictions of the instruments for 2023A semester in the following Gemini page : Link
  • GNIRS (1-5 micron spectrometer): As before, the short red camera is NOT available. YJHK imaging is available via the acquisition keyhole. A new low-resolution IFUs is being commissioned and will be offered for Fast Turnaround proposals only in semester 2023A.
  • NIFS (0.95-2.40 micron integral field unit spectrometer): available with or without AO capability. This instrument shares a port with NIRI and MAROON-X, hence it will only be available during specific blocks. NIFS is expected to be scheduled for two or three approximately one-month-long blocks during the semester. If the GNIRS IFUs are successfully commissioned in 2022, semester 2023A may be the last A semester where NIFS is offered.
  • GRACES: a high-resolution, R~67,500, optical (0.4-1 micron) spectrometer. Scheduled blocks to be determined with CFHT (where the instrument resides), based on demand. Semester 2023A may be the last semester where GRACES is offered.
  • GMOS South (0.36-1.03 micron imager and spectrometer): The noise problem on CCD-2 persists, as of August 2022; users are advised to dither or to place targets or spectral features on other parts of the detector. GMOS South may be removed for extensive engineering in the April to May 2023 period, to address this issue. In that case the instrument will not be available, and there will be reduced access to GMOS targets in the RA range of 8 to 12. Prospective users should check the instrument page for updates. The R600 grating is not available, however the new B480 grating is available, in 23A.
  • FLAMINGOS-2 (0.9-2.4 micron wide-field imager and spectrometer): offered in imaging, long-slit and MOS modes throughout the semester. The multi-object spectroscopy (MOS) mode allows simultaneous observation of up to 150 targets per mask over an area of 6'x2'.

Subaru Exchange Time:

  • The exchange of time between the Gemini and Subaru communities will continue in 2023A; around 5 nights are expected to be available on Subaru for the Gemini community via the exchange program. A summary of the Subaru capabilities in 2023A is given below, PIs should also consult the Subaru Call for Proposals
  • In addition, the Gemini community can propose shorter programs for Subaru's Service mode. PIs must indicate on the proposal whether regular or service time is requested. Service programs must be short programs of less than 4 hours duration including calibration and overheads, using one of FOCAS, IRCS(+AO), HDS, MOIRCS (imaging). Around 1 night is expected to be available in this mode for the Gemini community. Prospective investigators must carefully review the Service Program web page. In particular, some additional, detailed technical information must be provided at the time of Phase-1 submission. Service proposals are reviewed by the National TACs together with the regular proposals.
  • Subaru telescope downtime: the telescope will not be available for 1 to 3 days due to maintenance work on the electrical system. The dates will be announced later. 
  • Hyper Suprime-Cam (HSC) will have a maximum of four observing runs between March and June. Some filters require permission for use, prospective users should check the HSC web page. Important notice for HSC filters: all applicants must explicitly describe the filters they intend to use, in their proposal. The desired set as well as the minimum acceptable set should be clearly specified.
Proposal Submission

Proposers must use Gemini Phase-I Tool PIT. The PIT is a downloadable application that is used to provide "front-page" information including the title, abstract, and contact info for the investigators. Instrument configuration details, target coordinates, and observing constraints are also included in PIT. As noted above, the 2023A Phase 1 template must be used, and two attachements are required. Detailed help pages and video tutorials are available on the Gemini web site.

Please consider these suggestions and guidelines when preparing your proposal:

  • Please use the template that can be found at the PIT software distribution site (Latex and Word templates are available) to prepare the Essay section and team information and so on (please use GemPhase1_1_23A.docx/tex and GemPhase1_2_23A.docx/tex).
  • The scientific justification page has one-page limit for the text. Two additional pages can be used for references and figures. For page limits of other part of the essay, please refer to the description in the templates.
  • Be sure to include example Integration Time Calculator (ITC) output -- please see the instructions in the template.
  • When PI is a graduate student, please clarify who is his/her thesis advisor in the scheduling request section within the PIT.

For more details, please refer to Gemini’s page at

General Information

Observing Mode:

  • Target of Opportunity (ToO) mode will follow the general rules applied for the Gemini full partners (click here for more information). However, given the risk of ToO observation not being triggered in time, we will advise the Korean TAC to limit the allocation of the ToO program no bigger than ~30% of each band.
  • We encourage PIs to utilize Band 3 observations to greatly increase the chances of the program's getting data by relaxing observing conditions. 

Proposal Routes:
Regular proposal is available as it has been in the previous semester as follow:

  • Joint Proposal : Korean Gemini users can submit Joint Proposal by collaborating with the PIs of other Gemini international partners. (Joint Proposal)
  • Fast Turnaround (FT) program is available since Feb. 2019. FT runs by monthly-based submission and assessment. The total FT time per partner may not exceed 10% of the total partner’s time for a given semester. The time available for KR FT program in 2023A is 6 hours for Gemini-N and 6 hours for Gemini-S. (FT)
  • Poor weather program is available, and can be submitted at the time of regular Call for Proposal or any time during semester. Poor weather programs will be placed in Band 4, and neither the PI nor partner country will be charged for any time used. (Poor weather programs)
  • Director’s Discretionary Time (DDT) is also available. It’s, in fact, been available for any astronomer worldwide. (DDT)
  • Subaru-Gemini exchange Proposal : Gemini users can apply for observing time of the Subaru Telescope through the Time Exchange program. (Exchange Time)
  • Subaru HSC queue filler program Gemini community can also propose Hyper Supreme Cam queue "filler" program. Filler programs are executed in poor observing conditions (typically seeing >1.5 arcseconds, and/or poor transparency), up to 35 hours can be requested by a filler proposal. Execution is not guaranteed: observations are made only when there is no other program in the HSC queue. In recent semesters, typically of order 15% of HSC time has gone to filler programs. Applications may be submitted once per semester, check the following page for the next deadline (Subaru CfP page). Proposals must be sent through the Subaru submission system (NOT Gemini), and are considered only by the Subaru TAC. Note that only a short text summary of the program is required, not a full detailed Science Justification. The HSC queue filler program takes no time exchange cost(HSC filler programs)
  • Large and Long program (LLP) is not available as of now. There will be a discussion in the near future how to coordinate LLP for the Korean user community. (LLP)