Solar cycle dependence of the sun's radius at lambda = 525.0 nmThe Mount Wilson (California) synoptic program of solar magnetic observations scans the solar disk between 1 and 20 times per day. As part of this program, the radius is determined as an average distance between the image center and the point where the intensity in the FeI line at lambda = 525.0 nm drops to 25 percent of its value at the disk's center. The data base of information was analyzed and corrected for effects such as scattered light and atmospheric reflection. The solar variability and the measurement techniques are described. The observation data sets, the corrections made to the data, and the observed variations, are discussed. It is stated that similar spectral lines at lambda = 525.0 nm, which are common in the solar spectrum, probably exhibit similar radius changes. All portions of the sun are weighted equally so that it is concluded that, within spectral lines, the radiating area of the sun is increased at the solar maximum.
Document ID
19960014135
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Ulrich, Roger K. (California Univ. Los Angeles, CA, United States)
Bertello, L. (California Univ. Los Angeles, CA, United States)
Date Acquired
August 17, 2013
Publication Date
June 1, 1995
Publication Information
Publication: ESA, Proceedings of 4th SOHO on Helioseismology. Volume 2: Posters