Page Comparison

Instruments

Cycle 3 will offer the following instruments:

• Cryogenic Near-Infrared Spectro-Polarimeter (Cryo-NIRSP)

• Visible Spectro-Polarimeter (ViSP)

• Visible Broadband Imager (VBI)

Combining Instruments

Combining the ViSP and the VBI Blue and/or Red channels will be facilitated through three different configurations of the Facility Instrument Distribution Optics (FIDO).

• Option 1 : Config 1a

  • ViSP: Ca II K 393 nm, Ca II H 397 nm, Sr I 460 nm, H-Beta 486 nm, Mg I b2 517 nm, Fe I 525 nm, Na I D1 589 nm, Fe I 630 nm, H-Alpha 656 nm, Ca II 854 nm.

  • VBI-B: Blue continuum filter (B-Cont).

  • VBI-R: No light.

• Option 2 : Config 1c

  • ViSP: Mg I b2 517 nm, Fe I 525 nm, Na I D1 589 nm, Fe I 630 nm, H-Alpha 656 nm, Ca II 854 nm.

  • VBI-B: Ca II K, G-Band, B-Cont, H-Beta.

  • VBI-R: No light.

• Option 3: Config 3d

  • ViSP: Mg I b2 517 nm, Fe I 525 nm, Na I D1 589 nm, Fe I 630 nm.

  • VBI-B: Ca II K, G-Band, B-Cont, and H-Beta.

  • VBI-R: H-Alpha, Red continuum (R-Cont), TiO, and Fe XI (for on-disk applications only, not off limb).

Proposers are not required to combine post-WFC instruments and can choose to request only one instrument in stand-alone mode.

If Proposers decide to request the ViSP without the VBI, a default VBI configuration will be added by DKIST Science Operations.

Cycle 3 will not support using the Cryo-NIRSP and post-WFC instrumentation within the same Proposal even if the requested observations are separated out during the day or on consecutive days.

Visible Broadband Imager

Blue channel (VBI-B)

The VBI-Blue will be offered with its Ca II K, G-Band, Blue Continuum and H-Beta filters, respectively, depending on the choice of the coudé configuration.

Proposers are not required to use all available filters.

Visible Broadband Imager

Red channel (VBI-R)

The VBI-Red will be offered with its H-Alpha, Red-Continuum, TiO and Fe XI filters, respectively, depending on the choice of the coudé configuration.

Proposers are not required to use all available filters.

The VBI-Red is not available under the FIDO configurations 1a and 1c.

Visible Spectro-Polarimeter (ViSP)

The ViSP will be offered in its intensity and polarimetric mode limited to the 0.2 arcsec, 0.1 arcsec and 0.05 arcsec slit widths and the following spectral lines: Ca II K 393 nm, Ca II H 397 nm, Sr I 460 nm, H-Beta 486 nm, Mg I b2 517, Na I D1 589, Fe I 525, Fe I 630, H-Alpha 656 nm, Ca II 854 nm.

Proposers are not required to use all three arms of the ViSP.

Cryo-NIRSP

The Cryo-NIRSP spectrograph (SP) and context imager (CI) are offered during Cycle 3 for off-limb observations only. Observations by the spectrograph will be limited to Fe XIII 1074.7 nm, Fe XIII 1079.8 nm, He I 1083 nm, and Si X 1430 nm spectral lines. Unlike the other lines, the Si X 1430 bandpass is limited to spectroscopy-only.The ~4.5 nm bandwidth of the SP allows only one line to be observed at a single time. Observations of multiple lines can be acquired sequentially, but not at a fast cadence. A combination of spectroscopy and spectropolarimetry can be used within a single experiment for the selected lines. The context imager is offered in the He I 1083 nm bandpass only.

Two separate programs with mostly predefined settings for spectroscopic or spectropolarimetric observations are offered that Proposers can select from and use to build a custom experiment (very similar to Cycle 2): a coronal (off-limb) program and a prominence (and/or coronal rain) program.

FIDO independent combination

Proposers should be aware that there is a FIDO independent combination that can always be executed only needing some minor exposure time adjustment for the VBI Blue with minimal impact on summit operations:

• ViSP: Na I D1 589 nm, Fe I 630 nm.

• VBI-B: B-Cont filter.