Variations in photospheric limb darkening as a diagnostic of changes in solar luminosity

Abstract

view Abstract Citations (12) References (11) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Variations in photospheric limb darkening as a diagnostic of changes in solar luminosity Rosen, W. A. ; Foukal, P. V. ; Kurucz, R. L. ; Pierce, A. K. Abstract The paper reports on photospheric limb-darkening measurements obtained with the McMath Solar Telescope in July, September, and October 1980 as part of a continuing program to investigate possible long-term variations in the photospheric emergent flux. A total of 243 usable full-diameter scans were recorded over seven days in the clean continuum window at 4451-25 A. The limb darkening was found to decrease significantly between September 25 and 26. It is suggested that this decrease was caused by a decrease of the temperature gradient in the upper photosphere in the region above approximately tau(5000) = 0.5. The small increase in effective temperature that might accompany this limb-darkening variation is estimated using a standard radiative equilibrium photospheric model. Publication: The Astrophysical Journal Pub Date: February 1982 DOI: 10.1086/183742 Bibcode: 1982ApJ...253L..89R Keywords: Limb Darkening; Photosphere; Solar Flux; Solar Limb; Solar Constant; Solar Temperature; Solar Physics full text sources ADS |