Imaging Polarimetry of the 2017 Solar Eclipse with the RIT Polarization Imaging Camera

• Published in: Publications of the Astronomical Society of the Pacific 2020-02, Vol.132 (1008), p.1-15
• Main Authors: Vorobiev, Dmitry, Ninkov, Zoran, Bernard, Lee, Brock, Neal
• Format: Article
• Language: English
• Subjects: Stars and Stellar Evolution
• ISSN: 0004-6280; 1538-3873

Micropolarizer-based sensors are dramatically smaller and more mechanically robust than other polarimeters with similar spectral response and snapshot capability. To determine the suitability of these new polarimeters for astronomical applications, we developed the RIT Polarization Imaging Camera to investigate the performance of these devices, with a special attention to the low signal-to-noise regime. We found that, using the current calibration, RITPIC is capable of detecting polarization signals as small as ∼0.3%. To demonstrate the stability of RITPIC’s calibration and its extreme portability, we performed imaging polarimetry of the Solar corona in Madras, Oregon during the total Solar eclipse of 2017. The maximum polarization we measured was ∼47% in the blue and red color channels, which agrees well with the maximum value predicted for a Thomson scattering corona. Similarly, we found no strong deviations in the angle of linear polarization from the tangential direction. The relative ease of data collection, calibration, and analysis provided by these sensors suggest than they may become an important tool for a number of astronomical targets.