Imaging polarimeter for the 2.6 m Shajn telescope. Technical considerations and draft specifications

Abstract

Broadband polarimetry has been a substantial part of observing programs at the CrAO’s 2.6 m Shajn telescope, resulting in a number of impactful results. Currently, an instrument filling this role on the telescope is the multichannel fast modulation polarimeter NEOPOL. The constraints of its design, namely the use of photomultiplier tubes (PMTs) as light detectors, leaves many potentially interesting objects and phenomena beyond reach. In this paper, we present a case for the development of the new instrument for imaging polarimetry and consider some principal considerations concerning its design and specifications. As an optimal solution, we propose a specialized imaging device (as opposed to a versatile imager-spectrograph-polarimeter instrument) in the primary focus, based on the existing GE ELSE 2K x 2K CCD camera.