BENGALURU: Over the last few decades, India has taken massive steps towards achieving parity with the west in terms of space research and exploration. Apart from the varying success of programmes like Chandrayaan and Mangalyaan to developing launch vehicles that can carry heavy loads, the country has come a long way. Yet, the research infrastructure in India is still lacking.
The National Large Solar Telescope (NLST), proposed in the early 2010s, to study the sun’s microscopic structure, is yet to take shape. A recent paper by two researchers at the Indian Institute of Astrophysics has nudged the country a step closer to the goal of building the largest solar telescope in the world.
Scientists Saraswathi Kalyani Subramanian and Sridharan Rengaswamy have come up with a new metric to quantify the quality of images captured by solar telescopes, which could open up a world of possibilities for solar observation and the study of distant stars.
“It’s very likely that most of the parts for the telescope, especially the optics, would most likely be imported from abroad. So one of the key considerations was how to ensure that you’re getting what you need. Specifically, we needed to specify the quality of images that would be captured by the solar telescope that is going to be built, so that we could get the right optics,”
Rengaswamy explains. Ground-based telescopes inevitably experience resolution loss due to atmospheric disturbances when observing the Sun. The developed metric allows researchers to quantify the impact of the atmosphere and implement appropriate adaptive optics.
This essential mitigation strategy ensures that solar images captured by telescopes accurately depict the intricate details of the solar surface, facilitating advanced research and analysis. “This paper specifies parameters for both with and without the atmosphere.
If the telescope is on the ground, we are losing a certain amount of resolution but this measure helps us mitigate the impact of the atmosphere. If we do not have any adapted optics, then how do we quantify the quality of the images taken by a telescope?” Rengaswamy asks.
The NLST, when built, could be a huge asset for India’s space ambitions. Designed to study the Sun in minute detail, it not only helps us understand our nearest star better, but also study distant stars as well. “There are a lot of applications for a solar telescope, the foremost being that it’s sort of a laboratory for studying other stars.
Since the Sun is so close to us, we can see the solar surface in greater detail. We can then take whatever we learn from looking at the sun and apply it to other distant stars. We don’t have the luxury of observing distant stars in great detail, because they are so far away from us, but depending upon the type of the star and combined with the knowledge of our own Sun, we can extrapolate the features of a particular star we might be observing,” Rengaswamy concludes.
Two researchers at the Indian Institute of Astrophysics recently proposed a new metric that can quantify the image quality of solar telescopes, bringing India’s goal of building the world’s largest ground-based solar telescope one step closer.