Proposal due dates
Proposals are solicited for Yale observing time on the telescopes to which Yale has access. Unless otherwise stated, full proposals are due at 17:00:00 Eastern time.
The 2027A proposal deadline is September 11, 5PM
Keck I: 2D + 2G + 2L = 6 nights
Keck II: 1.5D + 2G + 2.5L = 6 nights
Palomar P200: TBD
SPECIAL NOTES AND CONSIDERATIONS FOR 2027A
Keck II facility downtime: There will be one 5-night shutdown period on Keck 2 during bright time in the 27A semester to complete dome, shutter, and high-priority infrastructure work. The work is intended to take place during May bright time, but dates will be finalized during the telescope scheduling process, taking into account scientific demand and the requirements of the infrastructure projects.
Keck I and Keck II bottom shutters: If not completed in 26B, there may be a period of 2 weeks on each of Keck 1 and Keck 2 where the bottom shutter will be fixed at 25 degrees elevation in order to replace wire ropes on the bottom shutters. Targets below 40 degrees elevation would experience vignetting. Please note on your coversheet if this restriction would be a significant impact to your science.
KPF and KPF-CC: KPF will not be available in 27A. KPF had an operations review in January 2026 that identified reduced detector thermal control and increased detector noise as key stability issues. In 27A, the team will begin work to address the hardware causes of these issues with an expectation of completion by the end of 27A.
Keck I AO: The following AO modes will be available for the full 27A semester:
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NGS and single star LGS
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KAPA in LTAO mode with STRAP or TRICK
There are no changes to the tip-tilt star magnitude limits for STRAP or TRICK. For more information please see https://www2.keck.hawaii.edu/inst/ao/
Keck II AO: Keck 2 AO with the new HAKA DM will be available in NGS mode with guide stars brighter than R=15, and in LGSAO mode with no restrictions.
SCALES: Arrival of SCALES has been delayed, and the instrument is currently expected to arrive at the Observatory in November. Pending a successful pre-ship review in October, SCALES is anticipated to install and begin commissioning at the end of the 26B semester and continue commissioning through the first few months of 27A. Routine science is expected to begin in April 2027. The imaging channel and low-resolution IFS are expected to be commissioned during the first few nights on sky, with the medium-resolution IFS commissioned next, followed by coronagraphy. Note that SCALES can still do high-contrast imaging and low-res spectra at performance no worse than NIRC2 without the coronagraph modes. Due to remaining schedule uncertainty, SCALES proposers should have a backup observing program, with a preference for NIRC2 observations. For more information on SCALES, see the SCALES homepage.
DEIMOS: DEIMOS will be unavailable February - April for commissioning of a new science detector. DEIMOS is expected to be available for science beginning in May. The Flexure Compensation System (FCS) for DEIMOS is currently non-functional. PIs should be aware that troubleshooting is ongoing but there is a potential that FCS will not be restored to service until after the detector upgrade is completed.
NIRSPEC: Nirspec will be unavailable for 5 weeks beginning in late April for routine service.
NIRC2-polarimeter: NIRC2 in polarmetric imaging mode, in both NGS and LGS AO, will be offered in a non-facility visitor mode for 27A. NIRC2 has an internal Wollaston prism and the K2AO system has two external half waveplates (HWPs) that are optimized for JHK- or L-band science. To swap between the JHK-HWP and L-HWP is a daytime task such that we cannot support both modes on a single night. NIRC2 polarimetry and non-polarimetry are supportable on a single night.
In polarimetry mode, LGS tip/tilt stars must be within 30-arcseconds of the science object
We ask observers interested in proposing for NIRC2p to reach out to WMKO and, if needed, we will put you in touch with the polarimetry team.
ZWFS, CRED2 and ORKID: ORKID will be available for use throughout the semester. ZWFS and CRED2 will be available until HISPEC FEI installation, expected around April/May. PIs who wish to use these technology demonstrators should consult with the Keck AO team before proposing and PIs should select NIRC2-NGS on their coversheet, with a clear description of what mode they will be using in their coversheet summary.
Instrument Hibernation: WMKO, in consultation with the Science Steering Committee after the receipt of the findings of the Instrument Suite Evolution task force (comprised of members of the WMKO community and WMKO science staff), is undergoing a process of hibernation and eventual decommissioning of instruments in the coming years as new capabilities arrive and to be responsive to pressures on WMKO resources. A hibernated instrument is not available for community use unless there is a significant emergent scientific and strategic need. After a year’s hibernation, the hibernated instrument will be completely removed from service and decommissioned. The community should begin planning for the following:
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NIRES: NIRES was hibernated in May 2026. Unless a compelling scientific or strategic need emerges, NIRES will be decommissioned at the end of the 27A semester.
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ESI: ESI was hibernated in July 2026. Unless a compelling scientific or strategic need emerges, ESI will be decommissioned at the end of the 27A semester.
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HIRES: HIRES will be decommissioned no earlier than the conclusion of 2027B. Due to the nature of the instrument and need to free the Keck I Nasmyth platform for future instrumentation, HIRES will not undergo a hibernation period and will instead transition directly to decommissioning. The final decommissioning timeline will depend on both the readiness of Zshooter, which is set to occupy HIRES’s current Nasmyth location, as well as the stability of KPF. A comparison of HIRES and KPF capabilities can be found HERE . As per instrument evolution process, WMKO is soliciting feedback from the community regarding the HIRES planned decommissioning. Please provide feedback through Keck Science Steering Committee members or address them to instrument_retirement@keck.hawaii.edu
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Additional instruments are under consideration for hibernation and eventual decommissioning in later semesters, with a focus on those instruments whose capabilities are being significantly superseded by new instrumentation.
Twilight Cadence Observing: In 2027A, institutions will continue to be able to allocate one twilight observing program per telescope, for a total of up to two programs. On Keck I, OSIRIS-NGS (imager only) will be available, and on Keck II, NIRC2-NGS will be available. Please note that due to ongoing AO upgrades, there may be times in the semester when AO is unavailable for cadence observations. Cadence program PIs are responsible for development of instrument scripts, providing documentation, and training of staff needed to make the cadence program a turnkey operation.
Click here for information about Yale’s facilities.
Proposal forms and submission (Yale astronomers only)
- Please see our internal Forms & Policies page for pre-proposal and proposal forms.
Additional telescope-specific instructions for proposal submission:
- Keck: Fill out a Keck cover sheet on the Keck observer login page and attach a PDF copy of it to your proposal before submission to the Yale TAC.
- Palomar: Fill out the P200 cover sheet on the Palomar website and and attach a PDF copy of it to your proposal before submission to the Yale TAC.
Completed PDF proposals and cover sheets / confirmations (where applicable) should be sent to Robyn Lisone (at yale . edu) before the deadline (as above).
Submitted proposals are posted on a password protected website for TAC review.