NATS 1740 Study Guide - Final Guide: Spiral Galaxy, Radial Velocity, Orbital Velocity

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Radu Campeanu

Document Summary

This part of the velocity cannot be measured with the. It can be measured only by observing the object"s gradual motion across our sky. Ionization nebeula: a colorful, wispy cloud of gas that glows because neighboring hot stars irradiate it with ultraviolet photons that can ionize hydrogen atoms. Bubble: (interstellar) an expanding shell of hot, ionized gas driven by stellar winds or supernovae, with very hot and very low density gas inside. 8: disk population: the stars that orbit within the disk of a spiral galaxy; sometimes called. Population i: radial velocity: the portion of any object"s total velocity that is directed toward or away from us. See ionization nebula: giant molecular cloud: a very large cloud of cold, dense interstellar gas, typically containing up to a million solar masses worth of material. Magellanic cloud) located about 150,000 light-years away; it probably orbits the milky.