AMOS was awarded in February 2016 for the design, manufacturing and installation of a 2.5 m telescope for Physical Research Laboratory (PRL) of India. The telescope is located in Mount Abu observatory site at Gurushikar in Rajasthan. The site situated 1680 m above the see level is one of the best in India for Astronomical Observations in the visible and infrared wavelengths (0.4 µm to 2.5 µm). PRL researches in astronomy and astrophysics focus mainly in the areas of exoplanets, evolution of solar system and other galaxies. The telescope will be operated mostly in combination with the optical fiber-fed high-resolution cross-dispersed echelle spectrograph named PARAS developed by PRL.
The telescope design is based on a Ritchey-Chretien Cassegrain configuration with a focal length of 20 m. The image quality in operation is maintained thanks to the active optic system where the 2.5 m primary mirror shape is controlled by means of 42 force axial actuators and the position of the secondary by means of a hexapod. Built-in wavefront sensor and camera provide feedback information respectively for the active optic and tracking closed loop. The telescope can host at Cassegrain focus one main instrument and two side instruments that are selected automatically.
AMOS has acquired in more than 30 years a large experience in design, analysis, fabrication and commissioning of 2 to 4 m-class telescopes. Strong of this experience, the multidisciplinary integrated team of the project was able to design the Mt ABU 2.5 m telescope in one year with a great mastering of the technologies and sub-systems development which are used.
Major components such as the mount structural parts, the 2.5 m primary mirror, etc. were fabricated at AMOS. The assembly of the telescope was performed in the integration hall of AMOS. The integration of all the components was followed by the alignment of the optics, the tuning of the axes, the functional tests and finally the performance on sky in September 2020. After dismounting, packing and multimodal transport, the telescope will be installed on-site in spring 2021.