Over the past several decades, a small but growing number of evolved stars, which rotate at speeds up to 75 times faster than the Sun, have been discovered. These elderly stars appear to defy our understanding of stellar evolution since they are expected to lose the bulk of their angular momentum much earlier in their lives. One proposed explanation for this mystery is that these stars are the products of stellar merger events.

The Dark Energy Survey (DES) completed its 6-year photometric survey of the southern sky, obtaining shape and color measurements of several hundred million galaxies and light curves of thousands of supernovae. I will present new cosmology measurements from Type Ia supernovae and prospects for the future. I will also discuss studies of other transients with DES including microlensing events, trans-Neptunian objects, and the elusive Planet Nine.

Magnetic fields are found in about 10% of stars with radiative envelopes. They are typically strong, simple, stable, and are not maintained by contemporaneous dynamos, for which reasons they are described as 'fossil' fields, i.e. fields left over from an earlier period in a star's life. Amongst stars earlier than about B5, magnetic confinement of their powerful winds leads to the formation of magnetospheres which can be detected across the electromagnetic spectrum, and which in turn are expected to lead to rapid angular momentum loss.