Barred spiral galaxy

A spiral galaxy with an elongated bar of stars and gas across its center, from whose ends spiral arms extend. The bar helps redistribute material through the galaxy.

Galactic bar: An elongated arrangement of stars and gas crossing the central region of a galaxy. This central structure distinguishes barred spirals and helps organize their inner spiral arms.
Milky Way: The barred spiral galaxy containing the Solar System. Its central bar is inferred from stellar surveys and shapes models of our own galaxy.
Spiral galaxy: A galaxy with a flattened rotating disk and spiral patterns of stars, gas, and dust. Barred spirals are a subtype of spiral galaxy, sharing its disk and arm structure.
Unbarred spiral galaxy: A spiral galaxy whose central region lacks a prominent elongated stellar bar. It has spiral arms without the central bar that defines this galaxy type.
Star formation: The process by which dense regions of molecular gas collapse to form stars. Gas concentrated along bars and rings can fuel localized star formation.
Density wave theory: A theory explaining spiral arms as patterns of enhanced density moving through a galaxy’s disk. It describes how spiral-arm patterns can coexist with a rotating central bar.
NGC 1300: A prominent barred spiral galaxy in the constellation Eridanus. Its sharply defined bar and grand-design arms make it a classic visual example.
Galactic nucleus: The central region of a galaxy, containing its densest concentration of stars and often a massive black hole. The bar crosses the central region from which the arms and inner structures are organized.
Elliptical galaxy: A galaxy with a smooth, rounded or elongated stellar distribution and little organized disk structure. Its shape and lack of prominent spiral arms contrast with barred disk galaxies.
Circumnuclear ring: A ring of gas, dust, and star formation surrounding a galaxy’s nucleus. Bar-driven gas inflow can accumulate near resonances and form a central ring.

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