Nebulae

Nebulae reveal how stars are born, how they influence their surroundings, and how stellar feedback sculpts the interstellar medium. In these images, Hubble resolves pillars, ionization fronts, shock boundaries, and embedded young stars with exceptional clarity. Many of these regions are active stellar nurseries where ultraviolet radiation from massive stars simultaneously triggers and suppresses new star formation. By comparing nebulae in different environments, astronomers constrain gas density, temperature, chemical composition, and mass-loss rates under real astrophysical conditions. This category is especially useful for education because it visually connects abstract processes such as feedback, collapse, and photoevaporation to concrete structures you can see directly in each frame.