A Novel and Powerful Way to Measure Coronal Magnetic Fields for the DKIST Era

University Of Hawaii, Honolulu

Investigators

Abstract

One of the major unsolved problems in solar physics is the question regarding how the solar corona is heated to temperatures over a million degrees. This project will develop and install new instrumentation on the institution's Scatter-free Observatory for Limb, Active Regions and Coronae (SOLARC) telescope. This instrumentation will operate in the infrared and will take advantage of a new approach to observing weak emission lines in the corona. These measurements will be used to derive the magnetic fields in the corona which will, in turn, be compared to existing numerical models that predict coronal heating. This project will support the training of the next generation of solar scientists. The PI will involve a postdoctoral researcher in the project and also plans to incorporate summer interns on the graduate and undergraduate level. In this project, the PI will construct a new instrument to be installed on the SOLARC telescope. This new instrument will take advantage of a novel approach that is based on permitted-forbidden line pairs and the Hanle effect, which has two significant advantages over previous techniques. First, it only relies on measuring linearly polarized emission signals which are typically two (or more) orders of magnitude larger than previously used circularly polarized emission lines. Second, it uses emission lines at longer infrared (IR) wavelengths where the scattered light from Earth's atmosphere is greatly reduced. The observed coronal vector magnetic fields will then be compared to magnetohydrodynamic (MHD) models to better understand the heating mechanisms within the corona. The development effort should also provide a powerful method that can be applied directly to the high spatial resolution capabilities of the Daniel K. Inouye Solar Telescope's (DKIST's) IR instruments.