Abstract
Until now a simple Photometric Sunspot Index (PSI) model was used (e.g. Willsonet al., 1981) to describe the contribution of sunspots to the solar irradiance deficit measurement by ACRIM. In this work we replace this model by a photometry of sunspot pictures for the period of 19 August to 4 September, 1980 taking into account the individual features, like lightbridges or umbral dots, of each spot. The main results of this preliminary analysis are: (1) theA u/A p ratios and alsos the α values vary in a wide range and are by no means constant as in the PSI model; (2) the general trend of the irradiance deficit from our analysis agrees well with the ACRIM measurements; (3) on some days there are differences of more than 50% between the deficits derived from our measurements and from the PSI model.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Allen, C. W.: 1973,Astrophysical Quantities, 3rd ed., Athlone Press, London
Foukal, P.: 1981, in L. E. Cram and J. H. Thomas (eds.)The Physics of Sunspot, Sacramento Peak Observatory, Sunspot, NM, p. 391.
Grossmann-Doerth, U. and Schmidt, W.: 1981,Astron. Astrophys. 95, 366.
Hudson, H. S., Silva, S., Woodard, M., and Willson, R. C.: 1982,Solar Phys. 76, 211.
Willson, R. C.: 1979,Appl. Opt. 18, 179.
Willson, R. C., Gulkis, S., Janssen, M., Hudson, H. S. and Chapman, G. A.: 1981,Science,211, 700.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Steinegger, M., Brandt, P.N., Pap, J. et al. Sunspot photometry and the total solar irradiance deficit measured in 1980 by ACRIM. Astrophys Space Sci 170, 127–133 (1990). https://doi.org/10.1007/BF00652658
Issue Date:
DOI: https://doi.org/10.1007/BF00652658