Various observatories around the globe started regular full-disk imaging of the solar atmosphere in the Ca II K line in the early decades of the 20th century. The archives made by these observations have the potential of ...

We report a transient intensity reduction/absorption burst observed at decameter wavelengths in close temporal association with an X2.0/3B flare near the disk center and the onset of a ``halo'' coronal mass ejection. The ...

We present an independent method for obtaining the three-dimensional space speed of a coronal mass ejection in the lower solar atmosphere through ray-tracing analysis of the thermal radio counterpart of its frontal loop ...

Using the data on sunspot groups during the period 1879-2004, we have found that the solar equatorial rotation rate during the odd-numbered sunspot cycles is well correlated with the equatorial rotation rate of the preceding ...

We report low-frequency (80 MHz) radio observations of circularly polarized non-thermal type I radio bursts ("noise storms") in the solar corona whose estimated energy is ~1021 erg. These are the weakest energy release ...

We present metric radio observations of quasi-periodic emission from the solar corona in close association with a ``halo'' CME and an ``EIT wave'' phenomenon. The radio event lasted for about 60 s. Its mean periodicity was ...

Here we present a systematic study of force-free field equation for simple axisymmetric configurations in spherical geometry. The condition of separability of solutions in radial and angular variables leads to two classes ...

The Haselgrove equations for radio-ray propagation in an anisotropic medium are used to determine the degree of circular polarization (dcp) of the low-frequency thermal radio emission from the outer solar corona with a ...

Assuming that metric type II radio bursts from the Sun are due to magnetohydrodynamic shocks driven by coronal mass ejections (CMEs), we estimate the average CME acceleration from its source region up to the position of ...