Galactic Dynamics is the study of the motion of stars and gas within galaxies, including their interactions and the forces that govern their behavior.

Kepler's Laws, specifically Kepler's Third Law, describe the relationship between the orbital velocity of a star and its distance from the center of a galaxy.

The Dark Matter Halo is the hypothetical dark matter halo that is thought to surround many galaxies, providing additional mass and influencing their dynamics.

The Bulge is the central region of a galaxy where most of the stars and gas are concentrated, forming a prominent spherical or elliptical structure.

The Disk is the flattened disk-shaped region of a galaxy where most of the stars and gas reside, forming a prominent spiral or barred spiral structure.

The Halo is the extended region surrounding the disk of a galaxy that contains stars, gas, and dark matter, extending far beyond the visible components of the galaxy.

Galactic Rotation is the phenomenon where stars in a galaxy exhibit a systematic rotation around the galactic center, creating a rotating disk-like structure.

Peculiar Velocity is the term used to describe the velocity of a star relative to the average motion of stars in its vicinity, representing the star's individual motion within the galaxy.

Velocity Dispersion is the phenomenon where stars in a galaxy exhibit a velocity dispersion, meaning they have a range of velocities, reflecting the different motions and interactions within the galaxy.

The Jeans Equation is the equation that relates the velocity dispersion of stars to the gravitational potential of a galaxy, providing insights into the dynamics and structure of the galaxy.

The Virial Theorem is the theorem that relates the total kinetic and potential energy of a self-gravitating system, providing insights into the stability and equilibrium of the system.

Spiral Structure is the phenomenon where stars in a galaxy form spiral arms, creating a distinctive and beautiful pattern in the galaxy's disk.

Barred Spiral Structure is the phenomenon where stars in a galaxy form a central bar-like structure, along with spiral arms, creating a distinct morphological feature in the galaxy's disk.

Elliptical Galaxy is the phenomenon where stars in a galaxy form an elliptical or spherical shape, lacking the spiral or barred spiral structure seen in other galaxy types.

Irregular Galaxy is the phenomenon where stars in a galaxy form an irregular shape, lacking a well-defined structure, spiral arms, or a central bar, creating a chaotic and fragmented appearance.