Novel spectropolarimetric observations of the He I multiplet are used to explore the dynamics of the chromospheric oscillation above sunspot umbrae. The results presented here provide strong evidence in support of the two-component model proposed by Socas-Navarro and coauthors. According to this model, the waves propagate only inside channels of

We present optical and near-IR linear polarimetry of V404 Cyg during its 2015 outburst and in quiescence. We obtained time-resolved r'-band polarimetry when the source was in outburst, near-IR polarimetry when the source was near quiescence and multiple waveband optical polarimetry later in quiescence. The optical-to-near-IR linear polarization

We present observational evidence of apparent plasma rotational motions in the feet of a solar prominence. Our study is based on spectroscopic observations taken in the He I 1083.0 nm multiplet with the Tenerife Infrared Polarimeter attached to the German Vacuum Tower Telescope. We recorded a time sequence of spectra with 34 s cadence placing the

An increasing number of both photometric and spectroscopic observations over the last decade have shown the existence of distinct sub-populations in some Galactic globular clusters. This evidence severely challenges the paradigm of globular clusters as the prototypes of single, simple stellar populations. In this review, we briefly summarise the

We compare the details of the distributions of HI, Hα , and far-UV emission in the spiral arms of M81, at a resolution of about 9'' (linear resolution 150 pc at 3.7 Mpc distance). The effects of extinction on the morphology of the Hα and far-UV are shown to be essentially bi-modal, i.e. the extinction is either very small or very large. The

The brighter water masers of NGC 1068 appear to trace molecular gas in a parsec-scale disk surrounding the central engine. We find evidence that these masers are reverberating in response to a central, common pump source, presumably the central engine. Firstly, the luminosities of individual maser features are correlated on time-scales as fine as