In a remarkable display of precision and scientific ingenuity, the Indian Institute of Astrophysics (IIA), an autonomous body under the Department of Science and Technology, has played a pivotal role in the Surya Tilak Project at Ayodhya. 

This initiative, aimed at bringing sunlight onto the forehead of Sri Ram Lalla, symbolizing divine blessings, during the auspicious occasion of Sri Ram Navami in the Chaitra month, stands as a testament to the fusion of technology and tradition.

The significance of the project lies in the dynamic nature of the solar calendar, which governs the positioning of the sun in the sky. 

As the English calendar date of Sri Ram Navami varies annually, following the lunar calendar, the precise alignment of sunlight onto the idol requires meticulous astronomical calculations. Delving into the intricacies of celestial mechanics, the experts at IIA have undertaken the task of identifying the calendar days of Sri Ram Navami for a cycle of 19 years, ensuring the replication of this celestial event with utmost accuracy.

At the heart of the project lies the design and optimization of an opto-mechanical system capable of channeling sunlight from the zenith of the temple onto the idol's forehead. 

Through a comprehensive approach encompassing the estimation of mirror and lens dimensions, as well as the manual mechanism for realigning the system according to the sun's position, the IIA team has crafted a solution that seamlessly integrates tradition with technology.

Amidst the ongoing construction of the temple, the IIA experts have adapted their design to suit the existing structure, ensuring the successful execution of the Surya Tilak on April 17, 2024. 

Their involvement extended beyond conceptualization, as they actively participated in testing, assembly, integration, and validation of the system on-site, underscoring their commitment to excellence.

While the implementation of the opto-mechanical system at the site is overseen by the Central Building Research Institute (CBRI), the device itself is manufactured by Optica, Bangalore. Looking ahead, plans are underway for the installation of a finalized design featuring four mirrors and four lenses, poised to be implemented once the temple construction reaches completion.

However, the efficacy of the mechanism is contingent upon environmental factors, with cloud cover or rainfall posing potential challenges. Nonetheless, the system boasts adaptability, capable of accommodating slight shifts in the calendar date of Sri Ram Navami, ensuring continued functionality and relevance.

The Surya Tilak Project stands as a beacon of innovation, bridging the realms of science and spirituality, while the contributions of the Indian Institute of Astrophysics serve as a shining example of scientific prowess harnessed for cultural enrichment and divine reverence.