The size of the sun is of critical importance to solar studies yet this is poorly known, let alone if and how the size varies over time. Paper published this week in Astronomy & Astrophysics.
Fig.1. Left: solar radius measurements (red symbols) made since the seventeenth century (Rozelot & Damiani 2012). The mean value of all these measurements is close to 960 arcsec. Right: focus on solar radius measurements made since 1970. …
Fig.2. Evolution of the solar radius variations over time for ground instruments (Solar Astrolabe, DORAYSOL and SODISMII monthly mean at 782.2 nm), balloon experiment (SDS), and space instrument (MDI) vs. daily sunspot number time-series. For each series, the mean has been
taken as reference value.
Ground-based measurements of the solar diameter during the rising phase of solar cycle 24
M. Meftah, T. Corbard, A. Irbah, R. Ikhlef, F. Morand, C. Renaud, A. Hauchecorne, P. Assus, J. Borgnino, B. Chauvineau, M. Crepel, F. Dalaudier, L. Damé, D. Djafer, M. Fodil, P. Lesueur, G. Poiet, M. Rouzé, A. Sarkissian, A.Ziad, and F. Laclare
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