Frequency Agile Solar Radiotelescope: A Next-Generation Radio Telescope for Solar Physics and Space Weather

TL;DR

The Frequency Agile Solar Radiotelescope (FASR) is a proposed advanced radio telescope designed to significantly enhance solar and space weather research through high-resolution, broadband imaging spectropolarimetry, building on proven capabilities demonstrated by EOVSA.

Contribution

This paper proposes modernizing and building the FASR, a next-generation solar radio telescope, leveraging recent technological advances and prior successful demonstrations to enable new scientific insights.

Findings

EOVSA demonstrated key FASR capabilities in solar magnetic field measurement.

FASR will provide high-resolution 3D imaging of the solar atmosphere.

FASR is low-risk with high scientific reward, ready for construction.

Abstract

The Frequency Agile Solar Radiotelescope (FASR) has been strongly endorsed as a top community priority by both Astronomy & Astrophysics Decadal Surveys and Solar & Space Physics Decadal Surveys in the past two decades. Although it was developed to a high state of readiness in previous years (it went through a CATE analysis and was declared ``doable now"), the NSF has not had the funding mechanisms in place to fund this mid-scale program. Now it does, and the community must seize this opportunity to modernize the FASR design and build the instrument in this decade. The concept and its science potential have been abundantly proven by the pathfinding Expanded Owens Valley Solar Array (EOVSA), which has demonstrated a small subset of FASR's key capabilities such as dynamically measuring the evolving magnetic field in eruptive flares, the temporal and spatial evolution of the electron energy distribution in flares, and the extensive coupling among dynamic components (flare, flux rope, current sheet). The FASR concept, which is orders of magnitude more powerful than EOVSA, is low-risk and extremely high reward, exploiting a fundamentally new research domain in solar and space weather physics. Utilizing dynamic broadband imaging spectropolarimetry at radio wavelengths, with its unique sensitivity to coronal magnetic fields and to both thermal plasma and nonthermal electrons from large flares to extremely weak transients, the ground-based FASR will make synoptic measurements of the coronal magnetic field and map emissions from the chromosphere to the middle corona in 3D. With its high spatial, spectral, and temporal resolution, as well as its superior imaging fidelity and dynamic range, FASR will be a highly complementary and synergistic component of solar and heliospheric capabilities needed for the next generation of solar science.