Proc. SPIE 6689, 66890B, 1−7, 2007
Solar Physics and Space Weather Instrumentation II
S. Fineschi and R.A. Viereck (eds)
© SPIE − The International Society for Optical Engineering

Analysis of the Comparative Responses of SMEI and LASCO

A. Buffington
Center for Astrophysics and Space Sciences, University of California San Diego

J.S. Morril
Space Science Division, Naval Research Lab., Washington, DC

P.P. Hick
Center for Astrophysics and Space Sciences, University of California San Diego

R.A. Howard
Space Science Division, Naval Research Lab., Washington, DC

B.V. Jackson
Center for Astrophysics and Space Sciences, University of California San Diego

D.F. Webb
Inst. for Space Research, Boston College, Boston, MA

Abstract

Surface-brightness responses of the C3 coronagraph in LASCO and of the Solar Mass Ejection Imager (SMEI) are compared, using measurements of a selection of bright stars that have been observed in both instruments. Seventeen stars are selected to be brighter than 4.5 magnitudes, not be known variables, and not have a neighboring bright star. Comparing observations of these determines a scaling relationship between surface-brightness measurements from one instrument to those from the other. We discuss units of surface brightness for the two instruments, and estimate a residual uncertainty for the present scaling relationship.