Last updated:
April 19, 2004


A 4.1-meter Telescope Built and Operated as a Brazil/USA partnership.

SOAR Telescope

SOAR site

The telescope


Gallery of images



Comments and

The Telescope Configuration

SOAR is an f/16 Ritchey-Chrétien optical design that delivering an 8 arcminute diameter field of view for science with a 50-Hertz tip-tilt stabilized image. SOAR has an altitude-azimuth mount that can accommodate eight “hot” instruments ready to make observations. The telescope has dual multi-bay Nasmyth observing ports on the sides of the telescope structure and three bent Cassegrain ports within the telescope itself. The incoming light beam is directed to a specific instrument with the tertiary mirror turret and subsequent fold mirrors. Each Nasmyth port can support an 8-meter telescope class instrument, which allows the SOAR partners to set-up shared use of appropriate instruments.


Optical System

The telescope features an adaptive 4.1-meter diameter, 10-centimeter thick primary mirror supported by 120 electro-mechanical force feedback actuators, light-weighted glass secondary and tertiary mirrors, and a fast tip-tilt gimbal for the tertiary mirror for first order wavefront corrections at 50 Hertz. All three mirrors are made of Corning’s ULE™ low expansion glass material. Goodrich Corporation developed the optical system, including the polishing of all three mirrors, the support systems for all three mirrors, and the integrated control system. SOAR has also been designed to take full advantage of a ground-layer adaptive optics system, already being designed, which will be installed as a future upgrade.

Telescope Mount

The telescope mount is a precision structure that moves in azimuth on a 3.6-meter rolling element bearing and in elevation on two pairs of preloaded tapered roller bearings. Vertex RSI designed and built the SOAR mount with a first mode frequency at 10 Hertz to allow this large structure to track smoothly, retarget accurately, and settle quickly. The mount also provides instrument rotators at Nasmyth foci.

Control System

The Telescope Control System is written in National Instruments LabView and runs on a set of Linux and Windows OS desktop computers. The LabView software allows seamless connectivity to the network of personal computers that control the various elements of the telescope, facility, and environmental control system, as well as the instruments. The SOAR telescope is set up to allow astronomers to observe remotely from anywhere in the world, with very minimal hardware and connectivity requirements, and only a telescope operator on site.