The Center for Astrophysics | Harvard & Smithsonian, through its collaborating entity the Smithsonian Astrophysical Observatory (SAO), offers opportunities for visiting scientists to engage with CfA | Harvard & Smithsonian science, research and resources. The Visiting Scientist and Visiting Student Program at Smithsonian Astrophysical Observatory expands scholarly exchange in atomic and molecular physics; infrared, optical, radio, and X-ray astronomy; planetary sciences; geophysics; solar and stellar physics; and theoretical astrophysics. Visits can vary from a few days to several weeks or months and, in some cases, last up to a year. This program annually attracts many international and national visitors. Stipend support varies with the length of the visit, with support being provided by the visitor's home institution or by fellowships such as a Guggenheim or from NATO, etc. Application to the program is made by directly contacting a member of the research staff to request support. Awards are dependent upon availability of funding.