Observing at WMKO

Instruments Available for Semester 2021A

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) please see restrictions listed below
        LRISp-ADC (polarimeter, with ADC) please see restrictions listed below

Keck 2 Instruments are:

        DEIMOS please see restriction listed below
        ESIi (ESI with the Integral Field Unit)
        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-LGS please see restriction for NIRC2-NGS/LGS/PY use of the vector vortex coronagraph below
        NIRC2-PY (NIRC2-NGS with the Pyramid Wavefront Sensor)


Subaru Time Exchange Instruments are:

FOCAS, HDS, Hyper Suprime-Cam, IRCS, MOIRCS or SWIMS (see below), CHARIS, SCExAO, VAMPIRES, 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 2021A:

Due to the likely continued impacts on the observatory and our observing community by COVID-19:

LRIS/LRISp: Observers are advised not to propose programs that depend critically on the LRIS red side. Blue side focused programs are fine. We anticipate delivery of the new red side detector in Spring 21, but cannot guarantee its availability in 21A at this time. For the latest information on the status of the LRIS red detector, please see the LRIS news pages.

NIRSPEC: NIRSPEC will be unavailable for 4 weeks in February for routine servicing to remove ice from the dewar window.


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 not operational. 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:

Target of Opportunity Observations: ToOs will be limited to instruments currently in use and must be triggered prior to 4:00 pm HST. All ToO observing teams should set up "at-home" observing at the beginning of the semester, well ahead of any possible ToO trigger events.

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 2021A, 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, MOIRCS or SWIMS, CHARIS, SCExAO, VAMPIRES, and IRD will be available. Please check the Subaru web site http://www.subarutelescope.org/Observing/index.html for detailed descriptions of these instruments, and the web site http://www.naoj.org/Observing/Proposals/Submit/call.html for instrument restrictions, particularly for visiting (PI-type) instruments SCExAO/CHARIS/IRD/VAMPIRES/SWIM, 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. The number of nights exchanged will be determined based on the demand from each community. In 21A, 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://www.naoj.org/Observing/queue/index.html for more details.

Subaru facility/instrument related restrictions for the 2021A semester:

  1. 3-nights downtime for new laser installation (Feb 1-3)
  2. 14-nights downtime for UPS replacement (July 18-31)
  3. Total 7-nights down for Telescope System Controller (TSC) upgrades.
  4. 10-nights downtime in June for PFS installation work.
  5. 4 HSC runs scheduled in S21A (Feb, Mar, June, July).
  6. No HSC run in April+May due to Top Unit Exchanger (TUE) maintenance.
  7. HSC Queue mode rule change - "1-night = 10 hours including overheads"
  8. Only NGS mode is available for AO188 observations (no LGS+AO)
  9. "SWIMS" (PI-type inst.) is available with risk-share.
  10. MOIRCS will be hibernated during the SWIMS operation, but if SWIMS turns out to be unavailable in S21A, we consider operating MOIRCS instead (depending on the demands for MOIRCS as a backup instrument).

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.

NIRSPAO is scheduled in campaign mode given limited demand for this configuration. If there are insufficient requests for its use, NIRSPAO may not be scheduled in a given semester.

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 07 August 2020 ccj.