Double Image Polarimeter—Ultra Fast: Simultaneous Three-color (BV R) Polarimeter with Electron-multiplying Charge-coupled Devices
Piirola, Vilppu; Poutanen, Juri; Berdyugin, Andrei V.; Kosenkov, Ilia A.; Berdyugina, Svetlana V.
Finland, Germany
Abstract
We describe a new instrument capable of high-precision (10-5) polarimetric observations simultaneously in three passbands (BVR). The instrument utilizes electron-multiplying charge-coupled device (EM CCD) cameras for high efficiency and fast image readout. The key features of the Double Image Polarimeter—Ultra Fast (DIPol-UF) are: (i) the optical design with high throughput and inherent stability; (ii) great versatility, which makes the instrument optimally suitable for observations of bright and faint targets; and (iii) a control system, which allows the use of the polarimeter remotely. Examples are given of the first results obtained from high signal-to-noise observations of bright nearby stars and of fainter sources such as X-ray binaries in their quiescent states.