HD 81809 has one of the highest-quality activity cycles from the sample of stars synoptically observed in the Mount Wilson Observatory HK Project.

This study, by Pedatella and others, employs a troposphere to lower thermosphere reanalysis dataset generated by the Whole Atmosphere Community Climate Model with data assimilation provided by the Data Assimilation Research Testbed (WACCM+DART).

It has long been recognized that during solar eclipses, the ionosphere-thermosphere system changes greatly within the eclipse shadow, due to the rapid reduction of solar irradiation.

Yuhong Fan and others carry out magnetohydrodynamic (MHD) simulations of the quasi-static evolution and eruption of a twisted coronal flux rope under a coronal streamer built up by an imposed flux emergence at the lower boundary.

We realized a laboratory experiment to study the polarization of the Na I doublet at 589:3 nm, in the presence of a magnetic eld. The purpose of the experiment is to test the theory of scattering polarization for illumination conditions typical of astrophysical plasmas.

Roberto Casini et al report on the measurements of the vector efficiency of a reflective blazed diffraction grating, which was specially coated in order to reduce the level of polarization in the diffracted light.

We explore new opportunities for solar physics that could be realized by future missions providing sustained observations from vantage points away from the Sun-Earth line.