• About DARP:
  Korea Time Allocation Committee is adopting the DARP (Dual Anonymous Review Process) from 25B semester. All Gemini proposals requesting time from the US, CA, BR, or AR have been following the DARP policy since 2021. For the Korean Gemini Users, 1yr (or plus) of a grace period (i.e. no penalty to proposals that do not meet the DARP policy) will be given so that they can be well trained/prepared for the DARP system. Korea will fully adopt the DARP policy in the proposal review process from 26B or 27A.

  Here is a brief summary for the DARP policy:

  Guideline for PIs

  • Enter information of the proposing team with the Phase I Tool (PIT) as usual.
  • Use the FT specific template.
  • The proposal template has been updated to be compliant with DARP starting on Feb 1, 2021
  • Avoid mentioning names and affiliations of the team in the PDF attachment that could be used to identify the proposing team.
  • Avoid claiming ownership of past work. (E.g., “my successful Gemini program in the previous semester (GS-18A-xxx)”, or “our analysis shown in Doe et al. 2020…”)
  • Including text in proposals discussing previous use of Gemini is ok, as long as that work is not referenced and program IDs are not listed.
  • Cite references in passive third person, e.g., “Analysis shown in Doe et al. 2020”, including references to data and software.
  • Do describe the proposed work, e.g., “We propose to do the following…”, or “We will measure the effects of …”
  • Unpublished work can be referred to as “obtained in private communication” or “from private consultation”.

  Guideline for Reviewers

  • Accept the assigned proposals based on abstracts whether you can provide an unbiased review or not.
  • Review proposals solely based on the scientific merit of what is proposed.
  • Do not spend any time attempting to identify the PI or the team. Even if you think you know, you can be wrong.
  • Utilize neutral pronouns (they/the PI/the team) when you write comments.
  • Flag the proposals that have not been sufficiently anonymized but DO NOT penalize them by lowering grades. (The FT support team will check the flagged proposals and send any violations to the Gemini Directorate for review.)

• All proposals to use Gemini in 2025B must use the 2025B Phase I template. When preparing PDF attachments, prospective PIs must follow the proposals template font size requirements in all cases, and avoid using smaller fonts in all sections of Gemini proposals (including in figures and tables).

• Classical mode observing is offered in semester 2025B for facility instruments only.

• Priority Visitor (PV) mode is offered at both Gemini North and Gemini South. If circumstances preclude having people on-site, programs awarded PV time will revert to queue mode. PIs requesting Classical observing must state in their technical justification how the observations could be done in queue mode (with remote eavesdropping for data quality assessment and decision making). The "Bring One, Get One" Student Observer Support Program remains unavailable for semester 25B.

• Rapid Target of Opportunity (rToO) Proposals: These can be accommodated for most instruments and their modes (and this includes non-LGS modes), subject to instrument availability on the dates upon which observations are triggered.

• GMOS On-Sky Arcs: GMOS baseline arcs are now taken on sky mixed with the science observations. For details on the updated GMOS arc baseline policy please see this page.

• Gemini North Engineering Time:

  • Shutdown time for (i) testing CEM-2 (Control Electronics Module associated with M2) with the existing top end and (ii) regular A&G maintenance. This will be combined into one single shutdown, which is expected to last approximately 5 weeks. We anticipate that the activity could start at the beginning of October, but cannot be precise at the time of this Call. The 25B shutdown will limit the availability of targets that are observable at RA 20 - 23 hours, and alternative targets should be prepared.

  • We also anticipate commencing work in  mid-May until October on the GNIRS camera turret and other issues, including reinstating the short-red camera mode, hence GNIRS will not be available for the first two months of the semester 25B. The exact dates for this intervention are still to be determined

• Gemini South is expected to be closed for the first 15 nights of semester 25B (August 01 - 15). These dates are provisional, and may be subject to change.

• Gemini North - IGRINS-2: The new IGRINS-2 instrument will be available for shared-risk observations during semester 25B. For further information, please see here.

• Gemini North - NIFS, NIRI & GRACES: No longer offered.

• Gemini South - GHOST PIs to receive reduced data products: The US NGO, in collaboration with Gemini, will offer reduced spectra for GHOST programs from all partner countries. The reduced files will be available through the Gemini Observatory Archive, together with the raw data.

• The Gemini Observatory Graduate Student Visitor Program is temporarily suspended for semester 25B. Details of the Graduate Student Visitor program are available here.

• Proposals for time on Gemini, and for time on Subaru via the Gemini-Subaru time exchange program, must use the Gemini Phase I Tool (PIT). Latex and Word templates are available to create PDF attachments which include the science and technical cases, and investigator information. The template has been revised to enable the anonymous review process, and to make proposals requirements uniform across the partners. Two attachments are required for the proposal so that team information can be separated from the science case.

• Additional options in the Time Requests module in the PIT are available for semester 2025B:
  • The Gemini 2025B Phase 1 Tool includes options to specify that the proposal is for the Aeon multi-telescope-facility system.
  • Also in the 2025B Time Requests module, there is an option to identify proposals which have synergies with James Webb Space Telescope science. The goal for providing this proposal category is to encourage development of science programs that benefit from a combination of Gemini and JWST observations. More information is available here.

Gemini North:

** Due to limited sky availability during the semester, GMOS MOS programs requiring pre-imaging should not have targets in this region, and other programs with targets in this region should not require a large amount of time, or have strict timing or observing constraints.

Gemini South:

** Due to limited sky availability during the semester, GMOS and FLAMINGOS-2 MOS programs requiring pre-imaging should not have targets in this region, and other programs with targets in this region should not require a large amount of time, or have strict timing or observing constraints.

Gemini North:
Facility Instruments:

• Gemini North Engineering Time: Shutdown time for (i) testing CEM-2 with the existing top end and (ii) regular A&G maintenance. This will be combined into one single shutdown, which is expected to last approximately 5 weeks. We anticipate that the activity could start at the beginning of October, but cannot be precise at the time of this Call. The 25B shutdown will limit the availability of targets that are observable at RA 20 - 23 hours, and alternative targets should be prepared.

• Commissioning of GPI-2. A total of 10 days has been allocated for this activity. It is anticipated that the commissioning run will be conducted during bright time, tentatively scheduled between November 30 and December 08. Please note that this may impact programs requiring infrared observations or those targeting objects within the RA range of 23 to 01 hours.

• Observations using the Gemini North Laser Guide Star (LGS) system are restricted to greater than 40 degrees elevation. How this translates into RA and Dec restrictions is indicated in the Table below.

• GMOS (North) - Available.  The GMOS-N B600 grating will not be offered because of its degraded sensitivity. The R600 grating will only be available for classical observing.

• GNIRS (North) - An intervention is scheduled to commence in mid-May and continue through October. As a result, GNIRS will be unavailable for the first two months of Semester 25B. The precise dates for this intervention have yet to be finalized.

  • When GNIRS becomes available during Semester 25B, it will support all operational modes, including imaging, longslit, cross-dispersed (XD), low-resolution and high-resolution integral field unit (LR-/HR-IFU), all of which can be adaptive optics (AO) fed. Additionally, the ShortRed camera is slated for replacement during this intervention. If the replacement is successful, this mode will be offered in Semester 25B on a shared-risk basis.

• Altair (Adaptive Optics; AO) (North) - Altair NGS modes (for GNIRS observations) will be available for 25B, assuming that GNIRS is offered. Altair LGS will not be available in 25B. Users interested in observations involving the Altair AO system should check the Altair Announcements page for updates on availability.

• IGRINS-2 - Available for shared-risk observations in semester 25B during specific blocks, subject to RA demand. Users interested in using IGRINS-2 must check the IGRINS-2 web pages

Visiting Instruments:

• `Alopeke (visiting instrument) - Available during specific blocks, scheduled according to demand, in semester 25B. In addition, ‘Alopeke may also be available outside those blocks on a best-efforts basis. 

• MAROON-X (visiting instrument) - Available during specific blocks, subject to RA demand. Note that it is now possible to check for MAROON-X prior target duplication: please see the instructions in the Phase I checklist for further details.

The following Gemini North instrumentation will not be available for Semester 2025B:

• NIRI - No longer offered. Near IR imaging (of smaller fields of ~16” field of view) will still be possible using the GNIRS acquisition “keyhole”.

• TEXES (visiting instrument) - Not available for semester 25B.

Gemini South:
Facility Instruments:

• Gemini South is expected to be closed  for the first 15 nights of  semester 25B. An engineering shutdown is currently anticipated to run from July 21, 2025 (semester 25B) - Aug 15, 2025 (semester 25B) for regular A&G maintenance. The 25B shutdown will limit the availability of targets that are only observable early in the semester (at RA 16 - 18 hours), and alternative targets should be prepared at later RAs.

• GMOS (South) - Available. The R600 grating will only be available for classical observing.

• GHOST - Available as part of the regular semester 25B Call for Proposals. In 2025B, GHOST is offered in both modes, as well as for non-sidereal targets and faint objects requiring blind offsets. The precision radial velocity mode (with simultaneous calibration) is not offered. The US NGO, in collaboration with Gemini, will offer reduced spectra for GHOST programs from all partner countries. The reduced files will be available through the Gemini Observatory Archive, together with the raw data.

• FLAMINGOS-2 (0.9-2.4 micron wide-field imager and spectrometer) - Available in imaging, long-slit and MOS modes throughout the semester. The multi-object spectroscopy (MOS) mode allows the simultaneous observation of up to 150 targets per mask over an area of 6’x2’.

• Observations using GSAOI + GeMS are restricted to greater than 45 degrees elevation. How this translates into RA and Dec restrictions is indicated in the Table below. The expectation is to have two or three laser runs of 7 nights, therefore up to about 150 hours will be scheduled at ITAC (Queue only, Bands 1 & 2 with IQ70 & IQ85). However, GeMS availability and scheduling will ultimately be driven by demand.
  

   

Visiting Instruments:

• Zorro - Available during specific blocks, subject to demand, in semester 25B. Scheduling will be driven by the demand.

• IQUEYE (visiting instrument, South) - Not available in semester 25B.

The following Gemini South instrumentation will not be available for Semester 2025B:

• IGRINS (visiting instrument, South) - no longer available, for 25B onwards.

The exchange of time between the Gemini and Subaru communities will continue in 2025B; around 5 nights are expected to be available on Subaru for the Gemini community via the exchange program. Subaru exchange time is open to all Gemini partners, including Chile. A summary of the Subaru capabilities in 2025B 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 IRCS, HDS, FOCAS or MOIRCS. Up to 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.

Details:

• Duplicate Subaru proposals submitted via other routes: If eligible PIs submit a proposal for Gemini Subaru exchange time and also submit the same proposal to a different TAC in parallel (e.g. researchers via the open use time offered in the Subaru Call, Gemini community PIs via the Gemini time-exchange program or Keck community PIs via the Keck time-exchange program), the proposers are asked to explicitly note the double submission in the proposal.

• Proposal submission: Proposals for time on Subaru via the Gemini time-exchange program are submitted via the normal Gemini Phase I process.

• HSC/PFS queue proposal length limits: For semester 25B, Gemini users can request no more than 3.5 nights (35 hours science time including overheads) in the case of HSC/PFS queue, and no more than 5.0 nights in the case of HSC classical requests.

• Subaru Strategic Programs (SSP): In S25B, PFS-SSP will be assigned about ~10-20 nights over ~3-4 observing runs. IRD-SSP is expected to be completed in S25B..

• Deformable Mirror (DM) upgrade for AO188: As part of the AO3k project, the DM has been upgraded from a 188-element bimorph mirror to a 3228-actuator magnetic mirror. AO188 provides three modes:

  • NGS/AO188 mode: Uses the 188-element Wave Front Sensor (WFS) + 3k-element DM);

  • LGS/AO188 mode: Uses the 188-element WFS + 3k-element DM;

  • NIRWFS/AO3k mode: Uses the NIR WFS + 3k-element DM.

While the NIR WFS provides high-performance AO correction, NGS and LGS mode performance is unchanged because they use 188-element WFS. Please consult the AO3k web page for more information.

• Instrument switches during the night: Switching between IRD, REACH, CHARIS, VAMPIRES and Fast PDI during a single or half-night observation is possible. Please check the Subaru Call for Proposals for the time required for switching instruments.

• Subaru telescope / instrument downtime:

  • There is a possibility of three (3) weeks of downtime after October for repairs to the dome's main shutter

  • NsIR Downtime: All instruments except for IRD on the NsIR focus - including IRCS, SCExAO(CHARIS, VAMPIRES, FastPDI), and REACH -  will be unavailable for about 2-3 months from August. After the installation, all IRCS, SCExAO, and REACH observations will be done with the NBS under shared-risk mode. Please see the IRCS and SCExAO webpage(s) for the possible impacts of the NBS.

• Subaru instrument and telescope restrictions:

  • The laser guide star (LGS) system for AO188 will be operated with TBAD (Transponder Based Aircraft Detector) with a shared-risk policy. Please consult the AO188 web page for the latest information.

The windscreen of the Subaru telescope is out of operation in 2025B, 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.