Ernst Öpik theorized that long period comets originated in that region named for this scientist, which is comprised of icy planetesimals.
With Theodore Walraven, this scientist proved that the light of the Crab Nebula was polarized by an incredibly strong magnetic field from within it. An estimate of the local mass density that is implied by the movement of stars is known as this man's namesake limit. In a 1927 paper, this scientist proved one of Bertil Lindblad's hypotheses when he used the differential motion of stars to propose a mathematical framework that assumes the existence of a globular cluster at the center of the Milky Way; in doing so he derived a quantity that scales with the azimuthal shear and another quantity that scales with vorticity, which are his namesake constants. Richard Mueller hypothesized the existence of Nemesis, a star that would cause mass extinctions when it perturbs a region named for this man. Ernst Öpik theorized that long period comets originated in that region named for this scientist, which is comprised of icy planetesimals. For 10 points, long term comets originate from what Dutch astronomer's namesake "cloud?"
With Theodore Walraven, this scientist proved that the light of the Crab Nebula was polarized by an incredibly strong magnetic field from within it.
Jan Hendrik Oort