Observing at WMKO

Instruments Available for Semester 2024A

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 I Instruments are:

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

Keck II Instruments are:

        DEIMOS see note below
        ESI see scheduling note 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-NGS limited availability, see below
        NIRC2-LGS limited availability, see below
        NIRC2-PY (NIRC2-NGS with the Pyramid Wavefront Sensor) limited availability, and see restrictions below


Subaru Time Exchange Instruments are:

FOCAS, HDS, Hyper Suprime-Cam, IRCS, 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 2024A:

KPF: KPF will be unavailable for 3 weeks in February while the instrument undergoes a service mission.

Keck I AO: Keck I AO (Osiris) may require periods of downtime in 24A to help facilitate KAPA work. Observing programs may be moved from preferred to acceptable observing periods to provide time for this work.

NIRSPEC: Nirspec will be unavailable from February 1- March 9 for routine servicing to remove ice from the dewar window.

Keck II AO: Keck II AO (Nirc2, Nirspao) will be unavailable for 3 weeks in late February through mid March.

DEIMOS: Please see https://www2.keck.hawaii.edu/inst/deimos/detector_issues.html for the latest DEIMOS detector performance status.

KPIC: KPIC will be unavailable until April, and will only be available for shared-risk science in collaboration with and supported by the KPIC team.

ESI: ESI will be scheduled in campaign mode to limit the number of reconfigs through the semester.

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

NIRC2: The vortex coronagraph in LGS mode is not available. Please see the NIRC2 manual https://www2.keck.hawaii.edu/inst/nirc2/ObserversManual.html#Section5.2.2 for information about vortex operations.

At-Home (pajama mode) Observing: At-home observing will continue to be available to observers. Please see https://keckobservatory.atlassian.net/wiki/spaces/MOSD/overview for information about remote observing, including at-home 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 2024A, with NIRC2-NGS and OSIRIS-NGS available for use. Each institution may allocate one twilight cadence program per telescope. Please note that due to ongoing AO upgrades, there will be times in the semester when AO is unavailable for cadence observations (see above). 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. More details can be found in the Cadence Policy.

FOCAS, HDS, Hyper Suprime-Cam, IRCS, MOIRCS, CHARIS+SCExAO, REACH, FastPDI, MEC, VAMPIRES, NsIR and IRD will be available at Subaru. 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, 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 23A, Subaru ToO observers will continue to 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 are executed in "classical" observing mode, except for HSC observations. Queue observing is the default observing mode for HSC; applicants who desire classical mode with HSC must justify their request. For all classical observations, Subaru may support half night allocations, but whole night allocations are preferred. Please check the HSC queue mode website https://subarutelescope.org/Observing/queue/index.html for more details on HSC observations.

Subaru facility/instrument related restrictions for the 2024A semester:

  1. From 2024A, Subaru will charge 30% of weather factor for the allocation of HSC queue mode programs, to increase the average completion rate of the programs. This means that 1 night is defined as 7 hours (including overhead) in the case of HSC queue mode. Accordingly, the requested time in HSC queue mode should not exceed 3.5 nights (requesting 3.5 nights science time corresponds to 5.0 nights total request, which is the maximum request allowed for Subaru "normal" programs). HSC programs requesting classical allocation do not need to consider this weather factor.
  2. There may be 14-27 nights of downtime due to the inspection of the hydraulic system of the telescope and dome drive system renewal (most likely in June-July).
  3. For facility instruments, HSC, HDS, IRCS(+NGSAO/LGSAO), FOCAS, MOIRCS will be available. LGS+AO with TBAD (Transponder Based Aircraft Detector) is available with a shared-risk policy.
  4. There will be at most three (3) or four (4) HSC observing runs in S24A, depending on the number of PFS commissioning runs and the schedule of the facility maintenance works.
  5. For PI-type instruments/device, CHARIS, FastPDI, IRD, MEC, REACH, VAMPIRES, NsIR Wave Plate Unit, and NIR WFS will be available for S24A. As usual, proposals requesting PI-type instruments/devices must include the relevant instrument PIs in the proposal. CHARIS, FastPDI, VAMPIRES, and MEC can be used together at the same time as the modules of SCExAO. For all information on available PI type instruments, see https://subarutelescope.org/Observing/Proposals/call.html
  6. A new NIR WFS (a visiting device, a near-infrared wavefront sensor inside the AO188 instead of the visible wavefront sensor) will be offered with a shared-risk policy.

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 data is 18 months except for data taken with NASA as the allocating institution which has a default proprietary period of 12 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 2023 ccj.