Development of a Polarimeter System for Solar Synoptic High-Sensitivity Observations

Solar activities are dominated by magnetic fields. Solar Coronal Mass Ejections (CMEs) are often associated with pre-existing filaments or prominences. The determination of the magnetic field in the solar chromosphere before, during, and after a CME event will allow us to derive the conditions that trigger CMEs and the magnetic field properties of the ejected material. Both ingredients are crucial to improve the current space weather forecast with respect to the probability of CME events and the potential impact on the Earth's magnetosphere. The near-infrared (NIR) He I 10830-Å is one of the most promising spectral lines to measure the filament and prominence magnetic fields, which is not available from current space-based programs.

To address the above scientific goals, California State University Northridge (CSUN) and New Jersey Institute Technology (NJIT) are receiving a large grant award from the National Science Foundation (NSF) to develop the first high-speed and high-sensitivity NIR polarimeter system that will be able to acquire polarization Stokes vector measurements at the He I spectral line with a polarization modulation speed up to 100 Hz to freeze the atmospheric turbulence. The developed instrument will be installed on one of the best sites on the Big Bear Solar Observatory (BBSO) and will be dedicated to solar synoptic diffraction-limited observations of the filament, prominence, and other solar active regions associated with CME events.

The instrument will be open to the US solar community to promote the study of the prominence and filament associated CMEs and improve theoretic models for the space weather forecast. The developed system will serve as a long-term platform to support the training of our diverse and underrepresented students as part of their early scientific career developments at the BBSO.