EDP Sciences
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Volume 402, Number 3, May II 2003
First Science with the ODIN satellite
Page(s) 1145 - 1150
Section Diffuse matter in space
DOI http://dx.doi.org/10.1051/0004-6361:20030346

A&A 402, 1145-1150 (2003)
DOI: 10.1051/0004-6361:20030346

Research Note

Daily measurements of the mean magnetic field of the Sun, 1968-2001: Anomalous distribution?

V. A. Kotov

Crimean Astrophysical Observatory, Nauchny, Crimea 98409 Isaak Newton Institute of Chile, Crimean Branch
(Received 4 December 2002 / Accepted 19 February 2003)

The mean magnetic field (MMF) of the Sun was measured in 1968-2001 by four Babcock magnetographs: of the Crimean Astrophysical Observatory, CrAO, of the Mount Wilson Observatory, MWO, of the Wilcox Solar Observatory, WSO, and of the Sayan Solar Observatory, SSO (in all nearly 13 thousand daily records). The MMF strengths recorded by these instruments on the same day, often deviate substantially from each other; this can hardly be explained by purely instrumental/solar causes alone. It is pointed out that (a) each magnetograph represents a linear electro-optical device detecting diminutive, ${\sim} 10^{-5} {-} 10^{-4}$, Zeeman circular polarization of a solar spectral line, with (b) no essential nonliner effects are expected, and (c) the observed MMF daily values must be normally distributed around a zero mean. The actual MMF distribution appears to be quite normal for records of the CrAO and SSO. Those of the MWO and WSO, however, deviate remarkably from the normal. The exact physical nature of this abnormity is unknown. It is suggested that the true cause might be connected with (a) the use of an image-slicer (at MWO and WSO), (b) entanglement of photons, (c) the statistical origin of light itself (due to the principle of uncertainty: "the instrument inevitably influences the output"), and (d) some instrumental/solar causes of poorly known origin and action.

Key words: Sun: magnetic fields

© ESO 2003