Light polarization of Mira stars

The results of polarimetric observations of long-period Mira variables obtained over the past 30 years at the Byurakan observatory are presented. Analysis of these observations shows that there is a real correlation between the degree of light polarization and the brightness of these stars. The maximum degree of polarization is observed at the middle of the ascending branch of the light curve. The degree of polarization is correlated with the period of brightness variation. The average degree of polarization of Mira stars increases with an increase in their period up toP=380 days.Translated fromAstrofizika, Vol. 39, No. 4, pp. 541–551, November, 1996.