Observing at WMKO

Instruments Available for Semester 2020B

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)

Keck 2 Instruments are:

        ESIi (ESI with the Integral Field Unit)
        NIRSPEC (without AO)
        NIRSPAO-NGS (NIRSPEC with Natural Guide Star AO, see restrictions below)
        NIRSPAO-LGS (NIRSPEC with Laser Guide Star AO; see restrictions below)
        NIRC2-LGS (note NIRC2-NGS/LGS is available with use of the vector vortex coronagraph)
        NIRC2-PY (NIRC2-NGS with the Pyramid Wavefront Sensor) available August-October


Subaru Time Exchange Instruments are:

FOCAS, HDS, Hyper Suprime-Cam, IRCS, MOIRCS, 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 2020B:

LRIS: The LRISr (red side) detectors are experiencing a readout problem on one of the two chips in the mosaic. Detailed information will soon be posted on the LRIS news pages. We are scheduling an LRIS service mission in semester 2021A to address this issue. Although a mitigation is in place to keep both detectors operable, we do not know how long the current mitigation will last. Thus, observers should place high priority science objects on the detector in the mosaic that is functioning normally, and observers are encouraged to contact their assigned staff astronomer for guidance.

Keck II: There will be a four night shutdown on Keck II from September 28 - October 1 for secondary mirror recoating and maintenance.

Keck II Infrared Pyramid WFS (Nirc2-PY): A new infrared pyramid wavefront sensor (PyWFS) will be available for on-axis science in August-October of 2020B, and then return to service in 2021A. This sensor uses H-band light for wavefront sensing, providing high resolution AO correction for stars up to an H-band magnitude of 12. Science verification with NIRC2's vortex coronagraph have demonstrated the high contrast capabilities of this sensor. The PyWFS is suited for point sources and performs well with tight binaries (separation < 0.5"), wide binaries (separation > 2") or binaries with a large flux ratio. The following proceedings describe the performance during early commissioning/science verification: http://ao4elt6.copl.ulaval.ca/proceedings/401-qGer-251.pdf.  Additional documentation will be added to this page as soon as available. Note that there is a separate coversheet selection (NIRC2-PY) for this mode.

Coversheet: The 20B coversheet will be released February 10 and has been updated to include a 'date specific' category. Please note that all date fields on the coversheet form now request HST dates.

Time Domain Astronomy: Observers will continue to have the ability to propose both cadence and ToO programs using the cover sheet. Policies for 2020B 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 2020B, 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, 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, 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 20B, 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 2020B semester:

  1. There will be up to 16-nights downtime in total for telescope system controller (TSC) upgrade works.
  2. HSC/FOCAS cannot be used until the middle of August 2020 due to Top Unit exchanger (TUE) maintenance. There will be at most 5 observing runs of HSC from September to January in S20B.
  3. LGS+AO mode is not available in S20B - only NGS+AO mode is available.
  4. IRCS has a new NB1984 filter (replaced with Br-alpha filter).
  5. MOIRCS will be hibernated from S21A (for two years). There are some updates of MOIRCS imaging filters and grisms for spectroscopy - see MOIRCS website for more details.
  6. IRD is available for open use, but still in a shared-risk mode. A new observing mode, REACH by combining SCExAO and IRD to realize high-angular resolution, high-contrast and high-spectral resolution observation is also available. CHARIS (with SCExAO+AO188) as well as VAMPIRES module in SCExAO are offered for open use observations. A new spectro-polarimetric mode using CHARIS is now available.
  7. IRD SSP has been started from S19A. Any proposal using IRD should clarify how its scientific aim is different from that of SSP
  8. COMICS will be decommissioned in July 2020 - COMICS is not available any more.

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 05 February 2020 ccj.