The Department of Astrophysical Sciences at Princeton conducts research across the entire spectrum of astronomy and astrophysics. The science we pursue generally runs the gamut of theoretical, observational, computational, large-scale survey, and instrumentation approaches to advancing the frontiers of knowledge of the Universe and its constituents. Our core research areas can be roughly divided into cosmology, galactic and extragalactic astronomy, planetary science, dynamics, stellar astronomy, high-energy astrophysics, the interstellar medium, plasma astrophysics, computational astrophysics, and telescope instrumentation. In these web pages, we summarize the specific projects and topics currently being studied in the department under these headings, and identify the faculty members engaged in these endeavors. While not complete, these summaries provide a good glimpse of the research opportunities available and of the current interests of its faculty.