GSU Astronomy Homepage


Pictoral Overview



CHARA Meetings

Observing Schedule

Telesope Status

Tower Cam


Current Conditions


IAU Commission 54

Mt. Wilson Observatory

Double Star Library

Users' Info

CHARA research is focused on the application of astronomical long-baseline optical/infrared interferometry to high resolution observations leading to the determination of the astrophysical properties of stars. The Center operates the CHARA Array, a six-telescope optical/infrared interferometric array on Mount Wilson, California. The CHARA Array provides the highest resolution of any telescope at visible and near-infrared wavelenghths making it among the most powerful facilities in the world for studying stars and stellar systems at resolutions not previously available. Among the Array's "firsts" are:
  • First direct detection of gravity darkening on a single star (Regulus)
  • First direct measurement of the "P-factor" in the Baade-Wesselink method (δ Cep)
  • First detection of hot exozodiacal dust around a main-sequence star (Vega)
  • First model-independent measurement of an exoplanet diameter (HD 189733b)
  • First angular diameter for a halo population star (μ Cas)
  • First image of a single, main-sequence star (Altair)
  • First direct image of an interacting binary (β Lyr)
  • Shortest-period (1.14 days) binary star system yet resolved 2 CrB)
  • First image of a binary star system in eclipse (ε Aur)
  • Earliest measurements of a nova fireball after detonation (Nova Delphini 2013)
The CHARA Year Eleven Science and Technology Review was held at GSU in Atlanta during 18-20 March 2015. The presentations from that gathering, and from earlier meetings, can be found here.
Built with funds from the National Science Foundation, Georgia State University, the W. M. Keck Foundation, and the David and Lucile Packard Foundation, ground was broken on July 13, 1996 at historic Mount Wilson Observatory. The facility was dedicated on October 4, 2000, and "first fringes," which demonstrated the technical feasibilty of CHARA's design, were obtained on September 19, 2001. Another three years of installation was required before the Array became fully operational in 2004, and routine, scheduled observing began in the spring of 2005. CHARA's 100th refereed scientific paper was published in 2013.
Read more about the CHARA Array and see our pictoral overview. For an expecially fine virtual tour of CHARA and other facilities on Mount Wilson, explore these spectacular spherical panoramas.
Collaborative teams have joined with Georgia State University scientists to extend the science capabilities of the Array through "beam combination" instruments that provide for imaging, increased wavelength, and spectral and polarimetric coverage. The greater CHARA collaboration presently includes: Georgia State University, National Optical Astronomy Observatory, Observatoire de Paris, University of Michigan, University of Sydney, and Observatoire de la Côte d'Azur.
Operating funding for CHARA is provided by the Division of Astronomical Sciences of the National Science Foundation and by the College of Arts and Sciences of Georgia State University.
Mount Wilson Observatory dominated the world of astronomy during the first half of the twentieth century. Learn more about this historic landmark here.