Astronomy & Astrophysics is a subject which attracts people of all ages; from a school going student to a person enjoying superannuation. The text deals with the fundamentals of Astronomy and Astrophysics. After briefing about the beginning of Astronomy, we have discussed various coordinate systems used to specify position of a place on the earth and an object in the space. Time is an important parameter and can help in having information about the relative occurrences of various events. The limitations of the observations with our eyes can be largely extended with the help of telescopes. Further, the telescopes help us for making observations of those radiations which cannot be seen by human eyes.

The fundamentals used for the study of various phenomena are summarized. Details about the Sun the closest star, has been studied in detail. Information about the solar family is described at length. Thermochemical reactions are responsible for creation of energy in the shining objects. Information about various types of thermochemical reactions is incorporated. Details of the galaxies and the universe are discussed. A brief description about the Cosmology — the science about the formation of universe is mentioned. The text cannot be considered as complete in absence of a discussion about the possibility of the existence of life in the universe other than that on the Earth.