Telescopes

Simonyi Survey Telescope

Telescope Mount Assembly (TMA)

The TMA's compact steel structure was designed to be rigid yet relatively lightweight, in order to slew 3.5 degrees (i.e., the field of view) within 4 seconds and settle within 1 second. The azimuth cable wrap allows rotation -250 to +250 degrees from north. The telescope is capable of non-sidereal tracking with angular rates of up to 220 arcseconds per second in both azimuth and elevation.

"Large Synoptic Survey Telescope mount final design", Callahan et al. (2016)

Go to the TMA page for a public audience.

Mirrors

The telescope has three reflective surfaces in the light path: the primary (M1), secondary (M2), and tertiary (M3) mirrors. M1 and M3 are formed out of a single piece of glass (M1M3) but have different curvatures. M2 has a 1.8 meter aperture in the center to allow light to pass to the camera.

Mirror sizes:

• M1: 6.7 meter effective diameter
• M2: 3.4 meter diameter (convex)
• M3: 5.0 meter diameter
• M1M3: 8.4 meter diameter

Etendue (integrated throughput, a measure of survey capability), defined as collecting area times the solid angle of the field of view, is 319 meters squared degrees squared for the design of the telescope and the LSST Science Camera.

M1M3 and M2 are coated with four layers. An adhesion layer of nickel-chromium (NiCr), a reflective layer of silver (Ag), another NiCr adhesion layer, and a final protective layer of silicon nitride (Si3N4).

Go to the mirrors page for a public audience.

Auxiliary Telescope

AuxTel has a 1.2 meter primary mirror and a slitless spectrograph. It will observe bright stars every night to obtain atmospheric transmission and improve the photometric calibration of the LSST data. Scientists will not need to process or analyze AuxTel data or apply the derived corrections themselves; this will be done as part of the processing with the LSST Science Pipelines.

Go to the AuxTel page for a public audience.