The authors have developed a star-and-sky chopping polarimeter for accurate measurements of linear polarization of starlight in the standard astronomical photometric U, B, V, R, and I bands. The instrumental polarization, ...

We have studied the time-dependent behavior of the He I 10830 A line. These studies show that (1) the fluctuations of the line width are uncorrelated with the equivalent-width fluctuations and (2) the autocorrelation curves ...