W49 A is a star-forming region (SFR) found in the constellation of Aquila. It contains 3 active regions: W49 North (W49 N), W49 South West (W49 SW) and W49 South (W49 S). We present preliminary results from two epochs (e-)MERLIN observations of all ground-state OH masers towards the star-forming region (SFR) complex W49 A. The first epoch of observations was done in full-polarization mode with MERLIN in 2005 while the second epoch was obtained only in dual circular polarization during the test observations of the upgraded e-MERLIN in 2013. The overall maser spatial distributions in both epochs are in good agreement. We found several new high velocity maser features up to +34 km s−1 and −28 km s−1. The magnetic field strengths are between 1.1 to 10.8 mG. All three sources show evidence of magnetic field reversal.

Propagation effects have been central to pulsar research and indeed were an integral part of the pulsar discovery and its prologue. I will summarize the early deduction process for establishing pulsar distances and refinements to the distance scale and modeling of the Galaxy in electron density and magnetic field. This will lead to the analogous current situation of understanding distances and media for extragalactic radio bursts. The role of magnetoionic media in precision pulsar timing and surveys for transients will be summarized. Finally, going full circle, searches for extraterrestrial intelligence (LGMs) also require attention to propagation effects.

We describe our method for measuring mass loss rates of F–M main sequence stars with high-resolution Lyman-α line profiles. Our diagnostic is the extra absorption on the blue side the interstellar hydrogen absorption produced by neutral hydrogen gas in the hydrogen walls of stars. For stars with low X-ray fluxes, the correlation of observed mass loss rate with X-ray surface flux and age predicts the solar wind mass flux between 700 Myr and the present.

Regions of intense velocity-shears are identified on statistical grounds in nearby diffuse molecular gas: they form conspicuous thin (~ 0.03 pc) and parsec-long structures that do not bear the signatures of shocked gas. Several straight substructures, ~ 3 mpc thick, have been detected at different position-angles within one of them. Two exhibit the largest velocity-shears ever measured far from star forming regions, up to 780 kms−1pc−1. Their position-angles are found to be also those of 10-parsec striations in the I(100μm) dust emission of the large scale environment. The B field projections, where available in these fields, are parallel both to the parsec- and to one of the milliparsec-scale shears. These findings put in relation the small-scale intermittent facet of the gas velocity field and the large scale structure of the magnetic fields.

A flare of OH maser emission was discovered in W75N in 2000. Its location was determined with the VLBA to be within 110 AU from one of the ultra-compact HII regions, VLA2. The flare consisted of several maser spots. Four of the spots were found to form Zeeman pairs, all of them with a magnetic field strength of about 40 mG. This is the highest ever magnetic field strength found in OH masers, an order of magnitude higher than in typical OH masers. We discuss the possible source for the enhanced magnetic field and its relation to the flare event.