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.

Microlensing is a powerful tool for discovering cold exoplanets, and the WFIRST microlensing survey will discover over 1000 such planets. The full modeling of each planetary microlensing event often requires significant investment of human and computing resources. When WFIRST releases light curves of thousands of microlensing events, it is important to detect the planetary systems fast, so an algorithm is needed to quickly classify all microlensing signals and prioritize rapid follow-up observations.

Despite the robust empirical supernova (SN) classification scheme in place, the underlying progenitor systems remain ambiguous for many SN subclasses, particularly stripped-envelope SNe. Mounting evidence over the past decade suggests that the mass loss in a large fraction of these systems occurs due to binary interaction. To date, however, only two binary companions have been detected: SNe 1993J and 2011dh.

Core-collapse supernovae and compact binary mergers are dense in neutrinos. Neutrinos drive the source inner working, carrying detectable imprints. Recent developments on the modelling of neutrinos and their conversions in core-collapse supernovae and compact binary mergers will be discussed.

Turbulence and reconnection are two phenomena that go hand in hand in astrophysical plasmas. On the one hand, magnetic reconnection is part of the turbulent cascade dynamics, being triggered at the interface of two different magnetic islands. On the other hand, the magnetic reconnection process ejects plasma jets that trigger turbulence in the reconnection exhausts. This talk will be devoted to this second aspect of the relationship between turbulence and reconnection. Two numerical studies are presented.

Massive stars as with all stars possess convective regions, from the PMS to their explosive demise. These regions likely participate in vigorous dynamo action, leading to the construction of magnetic fields that can be in superequipartition with respect to the convection when in a rapidly rotating regime. Moreover, near surface regions of sufficiently massive stars can be convectively unstable, producing the so-called iron-bump convection zone. This region too will likely be running a dynamo.

The activity presented here is inspired primarily by a division A Science Olympiad event I supervise, "Chopper Challenge". The elementary school student groups are provided with tools, including a sheet of card stock paper and their task is to build three structures: (1) rotating clockwise as viewed from above as it falls, (2) rotating counter-clockwise, and (3) rotating in a vertical plane as it falls. The groups with the largest total time of flight with proper rotations win. Now I am adapting that game for college students.