I will discuss some of the recent microlensing planet discoveries. Even though the numbers are small, these initial discoveries enabled the first measurement of the frequency of planets beyond the snow line. New, second-generation microlensing surveys are coming online, allowing an order of magnitude more stars to be effectively monitored for microlensing planets. In order to take maximum advantage of these new surveys, we need to systematically analyze all events for planets. I will present initial work I have done to explore these thresholds so that real signals may be separated from systematics. Understanding the detection thresholds will allow us to find planets even at the limits of detection and create a large, statistically rigorous sample of planets with which we can study properties of the planet population beyond the snow line.

I will present the results of a recent optical and near infrared spectroscopic survey of the young Galactic supernova remnant Cassiopeia A (Cas A). The survey encompasses the remnant's bright main shell, streamers of high-velocity material, and a portion of its extremely faint interior unshocked ejecta. From these data an extensive, high-resolution, three-dimensional (3D) kinematic reconstruction has been created. The 3D model provides us with the clearest look yet at the explosive outcome of a Type IIb supernova, and represents the first time we are able to investigate a remnant inside and out with unsurpassed clarity. I will discuss the observed complex ejecta structure in the context of potential explosion mechanisms, and offer a few thoughts on how these results can improve our understanding of core-collapse supernova dynamics in general.

The circum-galactic medium (CGM) of a galaxy is its gas reservoir and holds clues to its past and future evolution. I will present some of our recent work aimed at understanding the effects of starburst on the CGM. In this study, we used UV bright background QSOs to probe the CGM in foreground galaxies. We used the occurrence of CIV as an indicator for the presence of hot gas. Our comparison of the properties of the CGM in starburst (SB) and post-starburst (PSB) galaxies to normal galaxies with similar stellar masses and impact parameters revealed a much larger incidence rate of hot gas in SB and PSB galaxies. These galaxies display strong CIV transitions. On the other hand, their CII and SiII are barely detectable. In fact, even HI Lyman alpha transition was observed to be much weaker than CIV in SB and PSB galaxies. Our study also suggests that a starburst event heats the CGM at a time-scale of 100 Myrs to 1 Gyrs. This may help in understanding how galaxies regulate their star formation activity.