Smithsonian Astrophysical Observatory

Science Updates


A galactic bar is the approximately linear structure of stars and gas that stretches across the inner regions of some galaxies. The bar stretches from one inner spiral arm, across the nuclear region, to an arm on the other side.


The optical spectra of nearby star-forming galaxies provide astronomers with a comprehensive view of the ionized gas in their interstellar medium (ISM). Atoms in the gas, excited to varying degrees by ultraviolet radiation from hot stars or other processes, radiate in distinctive spectral features.

The Smithsonian Astrophysical Observatory (SAO) is a "research institute" of the Smithsonian Institution. It is joined with the Harvard College Observatory (HCO) to form the Harvard-Smithsonian Center for Astrophysics (CfA). Because these research activities share Harvard and Smithsonian staff and resources, the links at this website will take you to information posted on the "CfA" pages.