barredspiral
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. This bar stretches across the galaxy's core, extending from the ends of the spiral arms. The bar is thought to play a significant role in the dynamics of the galaxy, influencing the distribution of gas and the formation of new stars. Galaxies with bars are very common, with current estimates suggesting that over two-thirds of all spiral galaxies, including our own Milky Way, possess a central bar. The bar is typically formed from the gravitational interactions and instabilities within the galactic disk. It can channel gas towards the galactic center, potentially fueling a central supermassive black hole or triggering intense starburst activity in the bulge. The presence and size of the bar can also affect the morphology and evolution of the spiral arms themselves. Astronomers classify barred spiral galaxies using systems like the de Vaucouleurs system, where galaxies are denoted by symbols like SB or SAB, indicating the presence and prominence of the bar. Studying barred spiral galaxies provides valuable insights into galactic structure, evolution, and the processes that drive star formation throughout the universe.