ABSTRACT
The Universe is fascinating. Starting in ancient times, people have wondered about the nature of stars and how they might affect our lives. Our knowledge about them has progressed with time, often assisted by advances in fundamental science. For example, in the nineteenth century, the source of solar energy was believed to be the gravitational potential energy and perhaps the chemical energy. These were the only possibilities known at that time. It was only later, after the discovery of nuclear fusion, that scientists realized that the Sun is powered by nuclear energy. At present we are exploring the Universe in great detail with very sophisticated instruments. This has led to a huge amount of very precise data on various astronomical structures. The data has provided us with in-depth knowledge and understanding of the Universe on different length scales. Hence we are now able to construct detailed models, assisted by computer simulations, of objects such as stars, stellar clusters, galaxies etc. The branch of science that aims to understand the physics and chemistry of such heavenly objects is called Astrophysics. This field has seen remarkable developments in the last century and has now reached the level of a precision science.
