April 1, 2025: DKIST Announcement for Early Cycle 4 Proposal Planning

The National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST) is pleased to share the following information to assist with early proposal planning for Cycle 4 Observing. Full details will be published in the Cycle 4 Call for Proposals.

Dates and Deadlines

Key Dates for Cycle 4

Key Dates for Cycle 4
Release of Cycle 4 Proposal Call and Proposal Tool	April 29, 2025, 07:00 GMT
Opening of Submission Window	April 29, 2025, 07:00 GMT
Closing of Submission Window (Proposal submission deadline)	May 29, 2025, 23:00 GMT Please be aware that late Proposals (after the deadline has passed) or Proposals not submitted through the Proposal Submission Tool (Proposal Architect) will not be accepted.
Anticipated Execution Window (observing)	March 2026 - October 2026

Science Priorities and Research Targets

In Cycle 4, we continue to prioritize those proposals that aim to study active regions (specifically their fine-structure throughout the sun’s atmosphere as observable by the DKIST) requesting on-disk AR targets (e.g. sunspots, pores, active region filaments) or aim to study the corona off-limb (with the Cryogenic Near-Infrared Spectro-Polarimeter - Cryo-NIRSP). The latter is specifically to further the understanding of the corona through the coronagraphic capabilities of the DKIST.

In addition, DKIST plans on prioritizing flare research. Individual Proposers requesting flare observations are welcome to do so through the normal process of regular observing time allocation in response to the Cycle 4 Proposal Call (as before in Cycle 1, 2, and 3).

Furthermore, DKIST will dedicate additional time commensurate with up to the size of an individual observing window (about 7 weeks) within Cycle 4 for flare observing made available outside of the regular observing time allocation process. All data that is acquired within that dedicated time will be made public immediately after calibration by the DKIST data Center. During that dedicated time, the intent is to perform flare observations that are coordinated with interested space- and ground-based observatories. Observatories interested in joining the campaign are invited to contact the DKIST through a Google form https://docs.google.com/forms/d/1iHE3D-pi3UqdT4Nf7r88GGHORd7dekXGEksxW5kTtYI/edit. In order to assure that the coordinated observations are scientifically optimized and to the benefit of the community while well aligned with science objectives and goals of all the coordinating assets, a working group will be formed in the coming months leading to the Cycle 4 observing window. Overall membership of the working group will be limited. An announcement in Solar News after the release of the Cycle 4 Proposal Call will provide more information and details.

Pointing Target Types - All pointing targets are allowed and only constrained by individual instruments. Some targets are intrinsically risk enhanced.

Pointing Target Types - All pointing targets are allowed and only constrained by individual instruments. Some targets are intrinsically risk enhanced.

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

Off-limb observations and respective targets only:

Prominence.
Active corona.
Quiet corona.

Visible Broadband Imager (VBI), Visible Spectro-Polarimeter (ViSP), and Diffraction Limited Near-InfraRed Spectropolarimeter (DL-NIRSP)

On-disk and at/near-limb observations and respective targets:

Quiet sun.
Pore.
Sunspot.
Plages
Filament.
Coronal hole.

Near-limb observations with the DL-NIRSP are risk enhanced at the time of this announcement and the Cycle 4 proposal call release:

No data sets have been acquired yet - testing will be folded into Cycle 3 as much as possible.
Data Center pipeline will only be tested when data has been obtained.

Risk enhanced targets:

Spicules

Proposers should be aware that observations of limb spicules with the post-WFC instrumentation require a very well defined and stable lock-point target for the HOAO system in close proximity to the limb and likely offsetting the HOAO system in addition to very good and stable observing conditions.

This implies that despite the fact that spicules are always present, these observations are very demanding and the nominal risk is inherently enhanced (specifically regarding spatial resolution).

Observing Capabilities

Observing Capabilities

Observing Capabilities

Instruments

Cycle 4 will offer the following instruments:

Combining Instruments

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

Option 1 : Config 1a
- ViSP: offered spectral lines < 950 nm: Ca II K 393.4 nm, Ca II H 396.8 nm (includes H I 397 H-Epsilon in the red wing of Ca II H), H I 410.1 nm (H-Delta) New, H I 434.0 nm (H-Gamma) New, Sr I 460.7 nm, H I 486.1 nm (H-Beta), Mg I b2 517.3 nm, Na I D2 589.0 nm and/or Na I D1 589.6 nm (either individually or both lines combined when centered at 589.3 nm), Fe I 525.0 nm, Fe I 557.6 nm New, Fe I 617.3 nm New, Fe I 630.2 nm, H I 656.3 nm (H-Alpha), Fe I 709.0 nm New, Ca II 849.8 nm New, Ca II 854.2 nm , Ca II 866.2 nm New.
- VBI-B: Blue continuum filter (B-Cont) only.
- VBI-R: No light.
- DL-NIRSP: He I 1083 nm (arm 2), Fe I 1565 nm (arm 3).
Option 2 : Config 1c
- ViSP: 490 nm < offered spectral lines < 950 nm: Mg I b2 517.3 nm, Na I D2 589.0 nm and/or Na I D1 589.6 nm (either individually or both lines combined when centered at 589.3 nm), Fe I 525.0 nm, Fe I 557.6 nm New, Fe I 617.3 nm New, Fe I 630.2 nm, H I 656.3 nm (H-Alpha), Fe I 709.0 nm New, Ca II 849.8 nm New, Ca II 854.2 nm , Ca II 866.2 nm New.
- VBI-B: Ca II K, G-Band, B-Cont, H-Beta.
- VBI-R: No light.
- DL-NIRSP: He I 1083 nm (arm 2), Fe I 1565 nm (arm 3).
Option 3: Config 3c
- ViSP: 490 < offered spectral lines < 643 nm: Mg I b2 517.3 nm, Na I D2 589.0 nm and/or Na I D1 589.6 nm (either individually or both lines combined when centered at 589.3 nm), Fe I 525.0 nm, Fe I 557.6 nm New, Fe I 617.3 nm New, Fe I 630.2 nm.
- VBI-B: Ca II K, G-Band, B-Cont, H-Beta.
- VBI-R: H-Alpha, Red continuum (R-Cont).
- DL-NIRSP: Ca II IR 854 nm (arm 1), He I 1083 (arm 2), Fe I 1565 nm (arm 3).

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 4 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 and Red-Continuum filters.

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 393.4 nm
Ca II H 396.8 nm (includes H I 397 nm H-Epsilon in the red wing of Ca II H)
H I 410.1 nm (H-Delta) New
H I 434.0 nm (H-Gamma) New
Sr I 460.7 nm
H I 486.1 nm (H-Beta)
Mg I b2 517.3 nm
Na I D2 589.0 nm, Na I D1 589.6 nm (either individually or both lines combined when centered at 589.3 nm)
Fe I 525.0 nm
Fe I 557.6 nm (no Zeeman splitting, Lande factor g = 0) New
Fe I 617.3 nm New
Fe I 630.2 nm
H I 656.3 nm (H-Alpha)
Fe I 709.0 nm (no Zeeman splitting, Lande factor g = 0) New
Ca II 849.8 nm New
Ca II 854.2 nm
Ca II 866.2 nm New

All spectral lines marked as New are risk enhanced at the time of this announcement and the Cycle 4 proposal call release:

No data sets have been acquired yet - testing will be folded into Cycle 3 as much as possible.
Data Center pipeline will only be tested when data has been obtained.

Proposers are not required to use all three arms of the ViSP. In case not all arms are used, Science Operations will add lines to our discretion for testing purposes. This will not have any impact on Proposers.

Please be aware that specifically when including the Ca II H and/or K lines in the observation, the frame rate and cadence that the instrument can achieve is reduced (<20 Hz) due to the increased exposure times.

Diffraction Limited Near-InfraRed Spectropolarimeter (DL-NIRSP)

New

The DL-NIRSP will be offered in its intensity and polarimetric mode in its high-resolution and mid-resolution mode (New) and the following spectral lines:

Ca II 854 nm (visible arm 1) - only available in Config 3c
He I 1083 nm (IR arm 2) - Config 1a, 1c, or 3c
Fe I 1565 nm (IR arm 3) - Config 1a, 1c, or 3c

The mid-resolution mode is risk enhanced at the time of this announcement and the Cycle 4 proposal call release:

No data sets have been acquired yet - testing will be folded into Cycle 3 as much as possible.
Data Center pipeline will only be tested when data has been obtained.

Cryo-NIRSP

The Cryo-NIRSP spectrograph (SP) and context imager (CI) are offered during Cycle 4 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 3): 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 exposure time adjustment for the VBI Blue with minimal impact on summit operations:

ViSP: Mg I b2 517.3 nm, Fe I 525.0 nm, Fe I 557.6 nm, Na I D2 589.0 nm and/or Na I D1 589.6 nm (either individually or both lines combined when centered at 589.3 nm), Fe I 617.3 nm, Fe I 630.2 nm.
VBI-B: B-Cont filter.
DL-NIRSP: He I 1083 nm, Fe I 1565 nm.

Proposal Process

To familiarize yourself with the Proposing process during the DKIST’s Operations Commissioning Phase we recommend visiting the following information.

Please be aware that some of the information below - while providing a good overview - has not been updated for Cycle 4 yet. That should only be expected once the proposal submission window opens and the Cycle 4 Proposal Call is released.

Proposal Process

Proposal Process
Proposing Overview	https://nso.edu/dkist/proposing/
Proposal Preparation and Submission	https://nso.edu/dkist/proposal-preparation/ Please be aware that late Proposals (after the deadline has passed) or Proposals not submitted through the Proposal Submission Tool (Proposal Architect) will not be accepted.
Proposal Preparation and Submission Tool (a.k.a. Proposal Architect)	https://proposals.dkist.nso.edu/welcome The Proposal Preparation and Submission Tool is accessible but not updated to its Cycle 4 version yet. The Science Justification and Observing Strategy templates are not final yet. Please be aware of that the Proposal Preparation and Submission Tool will only allow to save information once the submission window opens.
Walk Through Instructions for Proposal Architect	https://nso.edu/dkist/pat-step-by-step
Proposal Selection	https://nso.edu/dkist/proposal-review/?_gl=1cuge7s_gaMTA5MjQ5MDgyNC4xNzA3NDEyMTE4_ga_TW89ZBTY53*MTcxMjA3NDk4MS4zMS4xLjE3MTIwNzUxNDIuMzIuMC4w
New Investigators/Proposers
If you are new to the process	https://nso.atlassian.net/servicedesk/customer/portal/3/article/1864433681

Data Center

To familiarize yourself with the DKIST Data Center, we recommend visiting the following information.

Data Center

Data Center
Searching, browsing and downloading of data	http://dkist.data.nso.edu/
Data Center Search Portal Manual	https://nso.atlassian.net/wiki/spaces/PDOI/pages/1802240116
DKIST Data Center User Tools	https://docs.dkist.nso.edu/projects/python-tools/en/latest/
Known Data Issues	https://nso.atlassian.net/wiki/spaces/DDCHD/pages/1959985377

Getting Help

Help Desk

Help Desk
Help Desk Portal	https://nso.atlassian.net/servicedesk/customer/portals
Knowledgebase	https://nso.atlassian.net/servicedesk/customer/portal/3/article/106103069