Physics

Dr Sujan K. Sengupta
Indian Institute of Astrophysics, Bangalore

About two decades ago, astronomers detected the first planet
out side the solar system. Since then more than 3000 of such
planet called as extra-solar planets or exoplanets have been
discovered. These discoveries have has revolutionized our
understanding of planets and their formation. While we know well
about the five kinds of planets
in our solar system, the discovery of at least 14 kinds of
extra-solar planets poses great puzzle regarding their physical
properties, atmospheric chemistry, internal geology etc.
Stars are formed through the gravitational collapse of
interstellar clouds but planets are formed through the
accumulation of matter in the proto-planetary disk.
The mass-range of objects formed through these two mechanisms
overlaps providing ambiguity in recognizing a planet from another
class of objects called Brown Dwarfs which are intermediate to
the least massive star and  the most massive planets but are formed                         like a star. In the present talk I shall discuss on new  detection methods
and characterization of extra-solar planets with the existing and
upcoming facilities.