Americanastrophysicist. In 1943 he found several spiral galaxies with very faint arms and unusually bright nuclei. Their spectra showed emission lines from hot ionized gases moving at high velocities. These so-called Seyfert galaxies have since been shown to belong to the wider class of objects with active galactic nuclei. In 1951 he observed the group of galaxies now known as Seyfert's Sextet.
Subjects: Astronomy and Astrophysics.