60. The UK in DKIST

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Introduction

The Daniel K. Inouye Solar Telescope is a 4m ground-based solar telescope currently under construction on the Haleakala mountain on the island of Maui, Hawai’i. It will be the largest solar telescope in the world by some way, with a diffraction limit a factor 3 smaller than that of any existing solar telescope. The UK has now joined the DKIST project, providing the cameras for four of the DKIST instruments. The UK DKIST consortium is financed by the Science and Technology Facilities Council, 8 UK universities, and Andor Technology plc. This nugget gives an overview of the DKIST, the UK’s contribution, and the opportunities for all UK solar physicists to get involved.

DKIST

The DKIST is led by the US National Solar Observatory (NSO) with funding from the National Science Foundation (NSF). It will operate in the optical and near-infrared and will be the pre-eminent ground-based solar telescope for the foreseeable future. Its adaptive optics will enable diffraction-limited observations with a spatial resolution of 25 km, less than the photon scattering mean-free path in the photosphere — a fundamental physical scale in the visible. It is located at an altitude of 3,000 m on Haleakala, Hawaii, giving the very low scattered light necessary for coronal studies. The DKIST first light will be in 2019, and it will serve the solar physics community to 2050 and beyond.

The main structural elements of the DKIST enclosure being installed; the basket on the crane with people in it gives an idea of the scale.
Fig 1: The main structural elements of the DKIST dome being installed; the basket on the crane gives an idea of the scale. Source NSO/DKIST.

The DKIST’s main science goals are:

  • What are the building blocks of solar magnetism?
  • How is magnetic energy built up, released and transported in flares and CMEs?
  • What is the origin of solar variability?

The key advances in the DKIST’s first-light instruments, which will be used to address these questions, are ultra-high spatial resolution (25 km) and ultra-high time cadence (10’s of ms) imaging, high resolution photospheric and chromospheric imaging spectroscopy and vector magnetometry, plus infrared coronal magnetometry.

Fig 2: The chromosphere in He 304 from AIA at 1.2″ resolution (right) and the same view in H-alpha from IBIS equipped with a ROSA camera (left) at 0.25″ spatial resolution (click for full resolution). The improvement in spatial resolution offered by DKIST will be about the same again. Image credit: Kevin Reardon PhD (NSO/QUB).

As a highly sophisticated facility, DKIST will normally be operated in service mode by expert astronomers on behalf of the PIs of observing proposals – like a ‘spacecraft on the ground’. The telescope has five first-generation instruments: VBI -the Visible Broadband Imager; VTF – the Visible Tunable Filter; ViSP – the Visible Spectro-Polarimeter; DL-NIRSP -the Diffraction Limited Near Infra-Red Spectro-Polarimeter and Cryo-NIRSP the Cryogenic Near Infra-Red Spectro-Polarimeter. The first light instrument will be the VBI, for which the UK’s ROSA imager is the prototype. Light from the primary can be shared between the first four of the five listed instruments simultaneously, allowing enormous flexibility in operations and thus science investigations. The Cryo-NIRSP instrument focuses on diagnostics of the faint corona, and will observe by itself, taking advantage of an unobstructed aperture and best coronal seeing conditions. Full details of the instruments can be found here.

The UK Consortium

The UK DKIST consortium institutes
Fig 3: The UK DKIST consortium institutes
The UK DKIST consortium is led by Queen’s University Belfast, and involves 7 other institutes (Armagh, Glasgow, MSSL, Northumbria, Sheffield, St. Andrews and Warwick). Finance for the consortium has been provided by the STFC, by the UK institutes involved, and Andor Technology plc who are investing internal resources in the camera development. The consortium will provide 9 identical cameras for four instruments on the DKIST, and in return the UK will have some guaranteed access time to the DKIST (in addition to competitively awarded open time). The consortium will also develop and implement aspects of the data analysis toolkit and help members of the UK community become involved with the DKIST science plan, and preparation of observations.

How to get involved

The UK DKIST consortium was formed for the benefit of the whole UK Solar Physics Community; it is not necessary to be working at one of the Consortium institutes to propose for observing time. However, the Consortium does aim to co-ordinate UK activities in DKIST, and to provide assistance with understanding the telescope, the instruments, and the process of preparing a proposal. There are two main ways that you can currently get involved;

  • Contribute data processing, analysis or forward-modelling software (contact Erwin Verwichte)
  • Contribute to the DKIST Critical Science Plan, and propose for observations (contact Lyndsay Fletcher)

Some of the DKIST’s science topics are described in the science cases. The UK DKIST consortium will be adopting the process for developing DKIST proposals outlined in the critical science plan.

Conclusions

The DKIST is an exciting new facility that will address many science questions of interest to the UK solar community. It will be able to work in co-ordination with ESA’s Solar Orbiter, though this will take very careful planning. We encourage the UK community to start developing their ideas for ground-breaking new science with the DKIST.