The University of Athens Observatory hosts a 0.4-m Cassegrain reflector inside the 5-m dome.

The main characteristics of the telescope are:

• Cassegrain reflector (CCT-16, DFM ENGINEERING INC., USA) with 0.4-m primary mirror and 0.15-m secondary mirror.
• Focal ratio f/3 for primary mirror and effective focal ratio f/8 for the telescope. Both primary and secondary mirrors have a pyrex substrate and are aluminized with a silicon monoxide overcoat.


• With a 3200 mm effective focal length the telescope provides a field of view of 11×16 arcmin with the SBIG ST10 XME CCD camera.
• An f/6.3 focal reducer can be placed on Cassegrain foscus, increasing the field of view up to 17×26 arcmin with the same camera.


• The focal plane position is between 0 and 20 cm behind the instrument mounting surface.
• The focus may be either controlled manually or commanded by the control system with a 2-speed motor.
• Low temperature (-40 °C) operation are guaranteed for the optical encoders.
• The telescope is equipped with a 9×60 finderscope and an illuminated reticle.


• A total of 20 kg of load can be mounted on Cassegrain focus, after balancing the optical tube with the equivalent counterweight.
• The telescope is equipped with a lightweight dew shield, which also reduces stray light.