Learn how galaxies are named, from ancient constellations to modern survey catalogs, and why some galaxies have several different designations.

Learn why galaxies stop forming stars, from gas depletion and feedback to black hole activity, environment, and cosmic evolution.

Learn what a star cluster is, how clusters form, the main types, and why astronomers study them to understand stellar evolution.

Learn how astronomers detect distant galaxies using telescopes, redshift, gravitational lensing, and deep-field surveys.

Explore how astronomers use light, spectra, simulations, and space telescopes to study galaxies and uncover their structure, evolution, and hidden matter.

Learn how galaxies merge, what happens during each stage, and why these collisions shape stars, black holes, and galaxy evolution.

Stars act as measurable clues that reveal a galaxy’s age, mass, motion, chemistry, and history.

Discover how telescopes capture galaxy images through optics, sensors, exposure stacking, and image processing used by professional observatories.