The great spirals, with their enormous radial velocities and insensible proper motions, apparently lie outside our Solar system.


Photographic Investigations of Faint Nebulae... (ed. 1920)


The great spirals, with their enormous radial velocities and insensible proper motions, apparently lie outside our Solar system.

The great spirals, with their enormous radial velocities and insensible proper motions, apparently lie outside our Solar system.

The great spirals, with their enormous radial velocities and insensible proper motions, apparently lie outside our Solar system.

The great spirals, with their enormous radial velocities and insensible proper motions, apparently lie outside our Solar system.