Exoplanets
My primary research interest has been the discovery and understanding of exoplanets. Broadly covering anything roughly like a planet outside our solar system, for me exoplanets is one of the most exciting fields of astronomy currently. While this is itself a broad field, my biggest interest has specifically been ground-based discovery of transiting exoplanets. This is roughly the idea that by observing many stars over time, we can find some stars that periodically dim as the planets orbiting them pass between us and their host star, causing small, but measurable, dimming events.
Surveys
Hand-in-hand with the search for transiting exoplanets is also working with the surveys that are used to detect detect these planets. This has meant the more hands-on work on how to handle the Kilodegree Extremely Little Telescope (KELT), and also understanding the cadence and survey areas of the Large Synoptic Survey Telescope (LSST).
Variables
Along with the search for exoplanets, all sorts of other variable sources show up, either as objects that get found along the way, or the other strange objects that show up when enough stars are monitored long enough to find other unusual objects. I also certainly find it interesting to try to understand the stranger objects that are observed during transiting planet searchers.