Galactic astronomy

dust floating in space

minor spiral arm of the Milky Way galaxy; contains the Solar System

one of two major spiral arms of the Milky Way galaxy

study of the Milky Way galaxy and its contents

in astronomy, the absorption and scattering of electromagnetic radiation by dust and gas between an emitting astronomical object and the observer

spiral arm of the Milky Way Galaxy

plane on which the majority of a disk-shaped galaxy's mass lies

spiral arm of the Milky Way Galaxy

study of the movement of stars

spiral arm of the Milky Way Galaxy

plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy’s center

the region of a galaxy in which life might most likely develop

velocity of an object relative to a rest frame

cavity light years across filled with gas blown into the interstellar medium from a hot star

theory to explain the spiral arm structure of spiral galaxies

reference frame used in astronomy

geographic region

galaxy that has a nucleus with excessive amounts of ultraviolet emissions compared with other galaxies

direction in space directly opposite to the Galactic Center, as viewed from Earth

empirically derived parameters A and B that characterize the differential rotational properties of our galaxy at the position of our Sun

in astronomy, the statistical dispersion of velocities about the mean velocity for a cluster of stars or galaxies

minor arm near the center of the Milky Way Galaxy

minor arm near the center of the Milky Way Galaxy