Helmos Observatory

Aristarchos Telescope

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 Announcements

The call for proposals for the observing period August 1- October 31, 2014 has been opened. The deadline for submitting proposals is March 31, 2014.

 

Telescope Design

 
FEATURES (with no instruments)

Height:

9.0 m

Width:

6.5 m

Weight (moving parts): 29 tons
Total weight : 34 tons
Weight (tube): 14 tons
Weight (altazimuth platform): 7.4 tons
Weight (prim mirror): 2.617 tons
Weight (sec mirror): 0.108 tons
Mounting system: Altazimuth with 6 drives per axis
Balancing system: Automated (ATB)
Encoding system: 2 tape encoders per axis with a resolution of 0.02"
 
 
OPTICS
Optical system: Ritchey-Chretien
Primary mirror diameter: 2280 mm
Focal ratio (primary): f/2.4
Secondary mirror diameter: 740.7 mm
Focal ratio (secondary): f/3.1
Final focal ratio: f/8
Optical aperture: 2200 mm
Focal length: 17714.45 for corrected field of view
17630.05 for uncorrected field of view
Field of view RC-corrected: 1.04 deg (diameter 321.6 mm)
Field of view uncorrected: 10.1' (diameter 52.8 mm)
Field of view (side port): 10.01'
Image scale: 1" = 85 microns (1.17"/mm)
Image quality on axis: < 0.35" (80% encircled energy, 350 nm - 1000 nm)
Focusing accuracy: +/- 0.005 mm (secondary mirror movement)
Travel range: +/- 10 mm (focusing mechanism)
 
 
ACQUISITION AND GUIDING UNIT (AGU)
Module 1: 2 off-axis autoguiders
Module 2: 4 side ports for instruments (uncorrected field)
Module 3: 1 main port for science instruments (RC-corrected field)
 
 
PERFORMANCE
Range of movement: +/- 200 deg (in azimuth)
Range of movement: +/- 90 deg (in altitude)
Rate of movement: max 2 deg per second (in azimuth)
Rate of movement: max 2 deg per second (in altitude)
Pointing accuracy: < 4" up to zenith distances of 70 deg
Tracking accuracy: < 0.5" in 10 min, 2" in 1 hr (open loop)
Tracking accuracy: < 0.25" in 10 min, 0.5" in 1 hr (closed loop)
Rotator tracking accuracy: 0.25" in 10 min, 0.5" in 1 hr
Radius of zenith blind spot: 2 deg
Mean time between failures: 750 hrs
Mean time to effect repair: < 4 hrs
Resonant frequencies: 16 Hz (fork), 21 Hz (tube)
Total weight capacity: up to 300 kg of instrumentation
Cassegrain weight capacity: up to 300 kg of instrumentation
Side port weight capacity: up to 100 kg of instrumentation
Operating temperature range: -10 C to +35 C
Operating humidity range: up to 80% relative humidity
Wind tolerance: up to 15 m/s (in operation)
Earthquake resistance: up to 2 m/square sec in any direction
 
CONTROL SYSTEM
Manual mode  
Automatic mode: Including advance activity scheduling
Remote control mode: Including planetarium mode
Levels of safety: 3 (software, signal, hardware limits)
 

Telescope & AGU description (pdf file)