Ultraviolet Coronagraph Spectrometer Observations of Density Fluctuations in the Solar Wind

Abstract

In the Letter ``Ultraviolet Coronagraph Spectrometer Observations of Density Fluctuations in the Solar Wind'' by L. Ofman, M. Romoli, G. Poletto, G. Noci, and J. L. Kohl (ApJ, 491, L111 [1997]), there was an error in the data reduction of the polarized brightness (pB). It was assumed that the cadence of the data and the exposure time are equal. However, the correct cadence is30 s longer than the exposure time because of the time it takes the polarizer to change orientation between exposures. This error does not affect the main result of the Letter, i.e., the detection of quasi-periodic density fluctuations in the solar wind. However, the correct cadences of the data in Table 1 are 30 s longer. This correction can be taken into account in Figure 1 by multiplying the times by 1.5 and dividing the frequencies by the same factor. Thus, the highest peak in the power spectrum is at 1.8+/-0.07 mHz (the corresponding period is 9.3+/-0.4 minutes). The correction factor is 1.1 in Figure 2 because of the longer exposure time in this observation.