Polarimetric Imager for Comets, PICO

[摘要] Weconstructedanimagingpolarimeter,PICO,thatwasoptimizedforcometsand/orcometaryobjects.PICOhasafield-of-viewof5$$'imes$$10$$'$$andemploysafixedWollastonprismasananalyzer.Inthecaseofpolarimetersusingadouble-beamprism,suchasaWollastonprism,lateralchromaticaberrationsoriginatingfromtheprismoftendegradetheimagequalityandmeasurementaccuracy.However,PICOsufferslittlelateralchromaticaberrationduetocompensationprovidedbynewlydesignedlenssystemsthatgenerateoppositelateralcolors.Owingtothisdesign,PICOcanobtainhighlyresolvedandveryaccuratepolarizationimagesthroughouttheFOV(field-of-view).Thetotalaccuracyisestimatedtobe$$DeltaPsimeq[(P/8{5})^2+0.3^2]^{1/2};$$%inpolarizationdegreeand$$hetaleq$$3$$^{circ}$$inpositionangle;thesevaluesaresatisfactoryforcometarystudies.

[学科分类] 天文学(综合)

[关键词] "comets: general";"instrumentation: polarimeters";"ISM: dust";"techniques: polarimetric"