Monitoring the Solar Temperature: Spectroscopic Temperature Variations of the Sun

Abstract

In the paper ““ Monitoring the Solar Temperature: Spectroscopic Temperature Variations of the Sun ÏÏ by David F. Gray and William C. Livingston (ApJ, 474, 802 [1997]), equation (4), giving the variation in observed line depth, is incorrect. It should read ddobs\ds (A0[1)dtrue (1[sA0)2 . The remainder of ° 5 following equation (4) stems from the incorrect equation and should be disregarded. These changes do not a†ect the results of the paper, except that a possible explanation for the nearly synchronized variation of the central depths of all three spectral lines no longer obtains. The authors note that an error in setting the continuum level is farthest from explaining the scaling behavior of the line depths shown in Figures 4 and 5 of the original paper. Continuum errors a†ect weaker lines proportionately more than stronger lines, which is just the opposite of what is observed. An error in zero level, which is close to the e†ect of scattered light, causes line depths to scale proportional to their depth. This is closer to what is observed, but does not go far enough in this direction, since the percent variation in the weaker C I line (depth 0.13) is only about half that of the Ti II (depth 0.48) and Fe I (depth 0.52) lines. 511