Observing at WMKO

Instruments Available for Semester 2022A

For detailed information about the instruments, please check the Instruments Home Page
For information about which instruments can be used on the same night, please check Instrument Sharing
a Resolving Power vs. Wavelength comparison of Keck instruments, please check this Instrument Comparison graph.

Keck 1 Instruments are:

        HIRESb (blue x-disperser)
        HIRESr (red x-disperser)
        LRIS-ADC (red and blue, with ADC)
        LRISp-ADC (polarimeter, with ADC) limited availability, see below

Keck 2 Instruments are:

        DEIMOS please see note below
        ESIi (ESI with the Integral Field Unit)
        KCWI limited availability, see below
        NIRSPEC (without AO) limited availability, see below
        NIRSPAO-NGS (NIRSPEC with Natural Guide Star AO, see restrictions below) limited availability, see below
        NIRSPAO-LGS (NIRSPEC with Laser Guide Star AO; see restrictions below) limited availability, see below
        NIRC2-NGS limited availability, see below
        NIRC2-LGS limited availability, see below
        NIRC2-PY (NIRC2-NGS with the Pyramid Wavefront Sensor) limited availability, see below


Subaru Time Exchange Instruments are:

FOCAS, HDS, Hyper Suprime-Cam, IRCS, SWIMS, CHARIS+SCExAO, VAMPIRES, REACH, MEC, Fast PDI, NsIR, and IRD. See below for limitations.

Telescope Limits

Please note that Keck I and Keck II have different eastern and western telescope limits. This affects the times objects will be available for observing. Objects can be acquired earlier on Keck II and followed later on Keck I.

Special Notes for Semester 2022A:

LRISp: The polarimeter for LRIS will return to service in March of 22A.

Keck 1 AO: Keck 1 AO (Osiris) may require periods of downtime in 22A to help facilitate KAPA hardware installation. Observing programs may need to be shifted in their acceptable observing periods to provide time for this work.

Keck 2 AO: Keck 2 AO (Nirc2-NGS/LGS/PY, Nirspao) will be unavailable from mid-February until mid-March.

NIRSPEC: NIRSPEC will be unavailable in February for routine servicing to remove ice from the dewar window and will return to service in early March.

NIRSPAO/NIRSPEC: Nirspec and Nirspao nights may be scheduled in campaign mode to limit the number of reconfigs into AO during the semester.

KCWI: KCWI will be unavailable beginning in early June for the installation of the red channel, KCRM. The polarimetry mode of KCWI will be available in shared risk mode during the timeframe KCWI is available.

KPIC: KPIC will be unavailable in 22A as it undergoes a phase 2 upgrade.


Please see the NIRC2 manual https://www2.keck.hawaii.edu/inst/nirc2/ObserversManual.html#Section5.2.2 for information about vortex operations.

DEIMOS: The top-left CCD on the detector mosaic is ~4 times noisier than the rest of the CCDs. Please see https://www2.keck.hawaii.edu/inst/deimos/detector_issues.html for guidelines on how to design your MOS masks with this issue in mind.

At-Home (pajama mode) Observing:

Time Domain Astronomy: Observers will continue to have the ability to propose both cadence and ToO programs using the cover sheet. Policies related to Target of Opportunity or Cadence proposals can be found at Too Policies and Cadence Policies. These policies are not applicable to Subaru Exchange time. TAC-approved Cross-institutional ToO (TDA) projects will continue to be able to interrupt observers at any Institution, to increase the utility of the ToO process.

Twilight Cadence Observing: The twilight cadence program will continue in 2022A, with NIRC2-NGS and OSIRIS-NGS available for use. Each institution may allocate one twilight cadence program per telescope. More details can be found in the Cadence Policy.

FOCAS, HDS, Hyper Suprime-Cam, IRCS, SWIMS, CHARIS+SCExAO, REACH, FastPDI, MEC, VAMPIRES, NsIR and IRD will be available. Please check the Subaru web site http://www.subarutelescope.org/Observing/index.html for detailed descriptions of these instruments. Please visit https://subarutelescope.org/Observing/Proposals/call.html for instrument restrictions, particularly for visiting (PI-type) instruments SCExAO+CHARIS, IRD, VAMPIRES, SWIMS, Fast PDI, MEC, REACH, and for filter availability of HSC. The SUBARU-KECK exchange will continue to have flexibility with regard to the number of nights available for exchange with the number of nights exchanged determined based on the demand from each community. In 22A, Subaru ToO observers will be able to interrupt Keck observers on the Subaru Telescope, and Keck ToO observers will be able to interrupt Subaru observers on the Keck Telescope. Compensation will be according to the policy of each observatory.

Subaru observations will be executed in "classical" observing mode. Subaru may support half night allocations, but whole night allocations are preferred. For HSC programs, Subaru may support "queue" observing mode if specified in the proposal, which may allow more flexible allocation such as e.g. very short 0.25 night request. Please check the HSC queue mode website https://subarutelescope.org/Observing/queue/index.html for more details.

Subaru facility/instrument related restrictions for the 2022A semester:

  1. Due to the Primary Mirror recoating work and some maintenance work, there is a scheduled downtime from July to September 2022, while the detailed downtime schedule has not yet been fixed.
  2. Due to maintenance work of the Top Unit Exchanger, HSC will be unavailable from February through early April, 2022.
  3. Due to the continuing LGS upgrade work, only NGS mode is available for AO188 programs in S22A.
  4. In addition to the facility instruments (FOCAS, HDS, HSC, IRCS+AO188), the following PU-type instruments/module are offered for open use in S22A. Please remind PIs proposing to use PI-type instruments/devices to include the instrument PI(s) as Co-I(s) of the proposal.

LGS-AO: A detailed set of guidelines for LGS-AO nights and information on the capabilities of the systems may be found on the LGS-AO page. Backup programs for LGS proposals are essential. Backup programs for LGS on Keck II may be either NGS programs or NIRES. On Keck I, either NGS-OSIRIS and non-AO HIRES may serve as a backup.

KOA (Keck Observatory Archive): Data from all instruments will be archived in the Keck Observatory Archive (KOA). The default proprietary period for all data is 18 months. If observers desire a different proprietary period they may request this through the Keck coversheet. Please see the KOA homepage for information on the archive. Please also see the KOA proprietary period policy.

For detailed information about the instruments, please check the Instruments Home Page

  (further observing information)

This page last updated 05 August 2021 ccj.