A New Spectropolarimeter at the Dodaira Observatory

摘要

We report a newly developed spectropolarimeter with a low-dispersion resolution (R = 40-200) and a wide coverage in wavelength (400-900 nm). It is mainly used along with the 0.91 m telescope at the Dodaira Observatory of the National Astronomical Observatory, Japan. This instrument and the related reduction software are described briefly. The present polarimetric accuracy (rms) is estimated to be [(P/50)~2 + (0.05)~2]~(1/2)%, where P is the linear polarization degree in percent. The spectropolarimeter has the advantage of being most useful in the polarimetric studies of both the continuum and the strong emission and/or absorption lines. It is mainly used for the short- or long-term monitoring of variable circumstellar polarization and of polarization in comets, and for studies on interstellar polarization.