Expertise: Extremely massive stars, nebular processes, data analysis techniques, special problems.
Has usually concentrated on a small number of genuinely special individual objects that give
astrophysical information unobtainable anywhere else: Eta Carinae, Crab Nebula, et al.
Director of Graduate Studies for Astronomy, U of MN, 2006-present.
UMN Senate, 2005--present.
UMN I.T. committee to evaluate re-appointment of the Head of the School of Physics & Astronomy, 2005-06.
UMN I.T. library committee, 2005—present
Highly ionized diffuse matter, particularly that associated with quasars, supernova remnants and X-ray sources - considered in "non-classical" nebular manner. Other aspects of X-ray sources and also very massive stars.
R.M. Humphreys, KD, & M.D. Koppelman, Astron. J., “The early spectra of Eta Car 1892--1941 and the onset of its high-excitation spectrum.”, SYNERGISTIC ACTIVITIES (2008)
G. Weigelt et al. incl. KD., “Near-IR interferometry of Eta Car…”, Astronomy & Astrophys (2007)
K. Hamaguchi et al. incl. KD, “X-ray spectral variation of Eta Car…”, Astrophys (2007)
J.C. Martin, KD, et al , “On the He II emission in Eta Carinae and the origin of its spectroscopic events.”, Astrophys (2006)
J.C. Martin, K. Davidson, & M.D. Koppelman, Astron. J., “The chrysalis opens? Photometry from the Eta Car HST Treasury Project 2002--2006.”, (2006)