Harvard University astronomers and Smithsonian Institution astronomers explore the cosmos together. The combination of the Harvard College Observatory (HCO) and the Smithsonian Astrophysical Observatory (SAO) is known as the Harvard-Smithsonian Center for Astrophysics (CfA).

News Releases

September 25, 2018

NASA has awarded a contract extension to the Smithsonian Astrophysical Observatory (SAO) in Cambridge, Massachusetts, to continue operations and science support for the agency's Chandra X-ray Observatory.

September 13, 2018

The explosions of stars, known as supernovae, can be so bright they outshine their host galaxies. They take months or years to fade away, and sometimes, the gaseous remains of the explosion slam into hydrogen-rich gas and temporarily get bright again – but could they remain luminous without any outside interference?

Latest Science Update

September 21, 2018

There are about 4433 exoplanets in the latest catalogs. Their radii have generally been measured by knowing the radius of their host star and then closely fitting the lightcurves as the planet transits across the face of the star.

SI Specific Information

SI-specific information regarding the government shutdown may be found at alerts.si.edu. SAO staff are encouraged to review the website for updated information