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Astronomy Colloquium

Wednesday, October 13, 2021
4:00pm to 5:00pm
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Online and In-Person Event
Imaging Stellar Surfaces at the CHARA Array
Theo ten Brummelaar (Director) / Gail Schaefer (Associate Director), Director, CHARA Array, Department of Physics and Astronomy, Georgia State University,

The CHARA Array is a six 1-m telescope optical/infrared interferometer constructed and operated by Georgia State University and located just to our north at Mount Wilson Observatory. With the largest baselines in the world and milli-arcsecond resolution, the CHARA Array has addressed many aspects of stellar astrophysics including measuring stellar diameters, imaging the surfaces of stars, studying the morphology of AGN cores, resolving the structure of circumstellar disks, imaging targets of opportunity like Novae, and mapping the orbits of close binary companions. We will provide an overview of the Array itself, focusing on the adaptive optics systems, the addition of a seventh movable telescope, experiments with fiber-based beam transport, and the development of the next generation of beam combiners. The new instrumentation will improve sensitivity and provide six-way beam combination at a variety of wavelength regions including R, I, J, H and K bands. We will then highlight recent science results and discuss the open access time that is available to the community through the NOIRLab time allocation process.

In-person attendance is limited to Caltech community members only (with a 74 person capacity limit in Hameetman Auditorium).

To view this talk via YouTube, please visit:

For more information, please contact Jim Fuller by email at or visit