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 Center for Astrophysics | Harvard & Smithsonian (CfA).

News Releases

January 13, 2020

NASA's Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star's habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface.

December 20, 2019

As the holiday season approaches, people in the northern hemisphere will gather indoors to stay warm. In keeping with the season, astronomers have studied two groups of galaxies that are rushing together and producing their own warmth.

Latest Science Update

January 24, 2020

A Cepheid variable star is one whose particular mass and age (along with some of its other physical parameters) result in brightness oscillations with a precise period proportional to the star's intrinsic luminosity.

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