Dean Hartshorn

Dean Hartshorn researches our cosmic backyard, focusing on the physical conditions of space within 100 parsecs of the Sun. His research interests include the local interstellar medium (LISM), the Sun and heliosphere, and stellar atmospheres. He uses high resolution ultraviolet spectra from space telescopes to probe the hot atmospheres of nearby stars and identify signatures left by clouds of cooler interstellar material along the line of sight. Hartshorn’s research focuses on potential cases of cloud-cloud interactions or “collisions,” where the interstellar gas in different clouds may be mixing, resulting in changes to the temperature, turbulence, velocity, and column density of the gas.

Prior to receiving his master’s degree in astronomy from Wesleyan University, Hartshorn attended several Smith College astronomy courses through the Five College Consortium as an undergraduate. Hartshorn returns to Smith to teach introductory classes on observing the night sky with telescopes. His other interests include dark sky preservation, education, and astronomy in the humanities.

“HST Observations of HD 166620 and Tau Ceti: First UV Spectra of a Magnetic Grand Minimum Star and the Extent of Tau Ceti’s Astrosphere.” B.E. Wood et al., 2026. The Astrophysical Journal, 998, 113.