| Abstract |
Triple-Range Imager and POLarimeter (TRIPOL) is a compact and lightweight instrument capable of imaging polarimetry. Using two dichroic mirrors, it splits wavelengths of 400nm to 830nm into 3-colors(g’ r’ i’). We employ an achromatic 1/2 wave-plate (rotating) plus a wire-grid (fixed) for polarimetry. Owing to the simultaneity over the three-colors, it provides, i) Spectral Energy Distribution, ii) Color-Magnitude Diagram and iii) Color-Color Diagram from the imaging photometry and iv) P(λ), wavelength-dependence from polarization measurement. We achieved the limiting magnitudes of 17 mag at r’- band for 60 sec integration times for imaging photometry, and ~0.3 % accuracy for polarization measurements for 15 sec x 4-position-angles x 10 rotation on 1 m size telescope.
This instrument was attached at the Cassegrain focus of the NCU 1-m Lulin telescope and tested in June 2012. The performance will be presented in the talk. |
