Astrophysics And Cosmology I - SS3 Physics Past Questions and Answers - page 2

Observational astronomy is a branch of astronomy that involves collecting and analyzing data from observations of celestial objects such as stars, planets, galaxies, and other cosmic phenomena. 

Telescopes are essential tools for observational astronomy, as they allow us to collect lighter and see more distant objects than our eyes can see. Telescopes work by collecting and focusing light using mirrors or lenses. There are many different types of telescopes, including refracting telescopes, reflecting telescopes, and radio telescopes. Each type has its advantages and disadvantages, and they are used for different types of observations.