Professor Kilgard is an astrophysicist whose background is in high-energy astrophysics. Prior to his move to Wesleyan, he spent almost a decade at the Harvard-Smithsonian Center for Astrophysics, where he worked on the Chandra X-ray Observatory–one of NASA's Great Observatories, and the X-ray counterpart to the Hubble Space Telescope. Professor Kilgard researches black holes in nearby galaxies with an interest in black hole growth and evolution across cosmic time. His lectures cover a wide variety of astronomical topics, including black holes and galaxies, X-ray astronomy, historical astronomy, and astrostatistics.

Professor Kilgard grew up in south Georgia but has purged his southern accent through many years in Boston, England, and now Connecticut. His love for all things space was inspired and encouraged by his grandfather, a veteran of the space program through the Gemini and Apollo eras. In addition to his work on black holes, he has become an amateur historian, working on both the restoration of Wesleyan's historic Clark refracting telescope and an exhibition on the history of astronomy in central Connecticut, which is on permanent dispaly in the Van Vleck Observatory library. When not researching X-ray binaries, he is an incurable nit-picker of sci-fi minutiae. This has infected his teaching, leading him to design courses on the intersection of science fiction and astronomy, as well as his outreach, with regular guest appearances at science fiction and fantasy conventions.