The CHARA Array

The CHARA Array is an optical / near-infrared interferometer located on Mount Wilson, CA. The facility is composed of six 1-meter telescopes, a beam synthesis facility, and a beam combination laboratory. Using the longest 331 meter baselines CHARA can resolve objects as small as 0.4 milliarcseconds (mas) at visible wavelengths.


The CLASSIC and CLIMB beam combiners of the CHARA Array are open air, aperture plane, broadband, single spectral channel instruments optimized for sensitivity. CLASSIC is the original two beam combiner used for the first science at CHARA, and it still has the faintest magnitude limit. CLIMB is a three beam expansion of CLASSIC that also provides closure phase measurements.


JouFLU is a two telescope beam combiner operating in the near infrared K’ band (lambda = 2.20 microns).  JouFLU spatially filters the light through optical fibers to produce high precision visibility measurements.


The Michigan Infrared Combiner (MIRC) combines the light from all six CHARA telescopes simultaneously.  It disperses the light across 8 spectral channels in the near infrared H-band (1.6 microns).  MIRC can be used to create images of stellar surfaces.  The precision closure phases are well suited to detecting faint binary companions.


PAVO is an integral-field-unit for measuring spatially-modulated fringes in the pupil plane.  It spectrally disperses light over a 630-950 nm bandwidth (R = 30).  Currently, PAVO can be used to combine the light from two telescopes. 


The Visible spEctroGraph and polArimeter (VEGA) was installed in September 2007 at the CHARA array. VEGA measures spectrally dispersed interference fringes, providing a spatial resolution of 0.3 mas and spectral resolutions from R = 6,000 to 30,000 over a wavelength of 480-850nm.

The following projects are under development at the CHARA Array:


ALOHA uses nonlinear optics that act like a mixer in a radio receiver, to shift the infrared radiations emitted by the observed astrophysical source to the visible spectral domain. This way, the light beam is more easily processed by mature optical devices and detectors.