The process of emergence of magnetic flux from the depths of the convection zone to the surface is presented in the framework of self-consistent model for the storage of field in the lower overshoot regions and as the mechanism responsible for some of the regularities observed in active regions. We have performed numerical simulations of the

We present maps of the sky at intermediate angular resolution (5 deg) of the declination range 35.0-45.0 deg obtained with the Tenerife cosmic microwave background (CMB) experiments using data up until 1992. The data were taken with bean-switching radiometers operating at 10.4 and 14.9 GHz. Right ascension scans were made at 2.5 deg declination

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Ten years of continuous measurements of the radial velocity of the Sun have been used to estimate the contribution of various solar surface phenomena to the observed background solar velocity spectrum (BSVS). The characteristics of this spectrum are of great importance, as they represent the ultimate limit on the sensitivity of measurements of

We derive inequalities which restrict the precision of the Stokes parameters imposed by photon noise. The signal-to-noise ratio of the measured Stokes parameters is never better than the square root of the number of detected photons. In case of weakly polarized sources (i.e., most astronomical sources), such an inequality imposes no practical limit