Observing at WMKO

Instruments Available for Semester 2024B

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)
        KPIC see note below
        NIRSPEC (without AO)
        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) no longer available


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 2024B:

KPF: KPF will be unavailable for 4 weeks in November for installation of a thermal enclosure and mechanical cooling system. Note that this time frame may be shifted somewhat as more information on delivery of these items becomes available.

KPF: A new coversheet form should become available in the early April timeframe that will allow the option of providing supplemental KPF PRV target information. The target information would be used by the KPF cadence team to test an algorithm for suggesting the optimal distribution of KPF nights as a possible input to the scheduling process.

Keck II Pyramid WFS: The Keck II Pyramid WFS is being retired in semester 24A and will no longer be offered for science use.

KPIC: KPIC is being offered as a facility instrument in semesters 24B-25B. However, KPIC availability is contingent upon successful completion of an operations handover review to be conducted in June 2024. PIs should have backup NIRSPAO or NIRC2 programs planned if KPIC is not available. Documentation for KPIC can be found here: KPIC Proposal Information

Keck II AO: Keck II AO (Nirc2, Nirspao) will be unavailable for 3-4 weeks in mid/late August to mid-September

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

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. This may impact the ability to schedule certain date critical observations.

NIRSPAO: (late addition 3/19/24) In early 2025B, NIRSPAO will no longer be available for science. NIRSPAO's availability is dictated by the arrival of the SCALES instrument which is currently scheduled for delivery at the beginning of 2025B. During the next two TAC announcements, the SCALES delivery and corresponding NIRSPAO unavailability will updated.

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 2024B, 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. 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 2024B semester:

  1. There is no scheduled downtime for 24B.
  2. Starting from 24A semester, the allocation time of HSC queue mode programs will consider 30% weather factor. Accordingly, the requested time in HSC queue mode should not exceed 3.5 nights. In other words, we regard 7 hours of HSC queue observing time (including overhead) as 1 night exchange. In the case of classical request, users can request up to 5 nights.
  3. The laser guide star (LGS) system for AO188 will be operated with TBAD (Transponder Based Aircraft Detector) with a shared-risk policy. Please check the AO188 webpage for the latest information.
  4. The near-infrared wavefront sensor (NIR WFS) of AO188, which is a PI-type device, is open in shared risk mode, only for limited modes with IRCS and SCExAO/CHARIS. Please refer to the website of NIR WFS and IRCS for detailed information.
  5. Following Facility instruments are available for S24B: FOCAS, HDS, HSC, IRCS(+AO188), MOIRCS
  6. Following PI-type instruments/devices are available for S24B. As usual, proposals to use visiting instruments/devices must include the relevant PIs as Co-investigators of the proposal.
    • CHARIS with SCExAO+AO188 (including spectro-polarimetric mode)
    • VAMPIRES with SCExAO+AO188 (cameras have been upgraded for improved sensitivity, speed and dynamic range. A new multi-band imaging mode is available.)
    • Fast PDI with SCExAO+AO188 (in a shared-risk mode)
    • MEC with SCExAO+AO188 (in a shared-risk mode)
    • REACH (combination of SCExAO and IRD for single-mode fiber spectroscopy)
    • IRD with AO188 (NGS-AO or LGS-AO, in a shared-risk mode)
    • NsIR Wave Plate Unit (a visiting device for IRCS/SCExAO polarimetry mode)
    • NIR WFS (a near-infrared wavefront sensor inside the AO188 instead of the visible wavefront sensor)
  7. Note that CHARIS, FastPDI, VAMPIRES, and MEC can be used together at the same time as the modules of SCExAO
  8. REACH can be used simultaneously with CHARIS with any dispersion modes, but the wavelength coverage of CHARIS will be from 1850 nm to the longest wavelengths shown in the CHARIS web site.
  9. Instrument switching between IRD, REACH, CHARIS, VAMPIRES, Fast PDI, and MEC in one or half observation night for one observing proposal is possible. Please check the official Subaru call for details.

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 05 February 2024 ccj.