 Taphao Thong was discovered by detecting the changes in its star's radial velocity as the planet's gravity pulls the star around.This was achieved by observing the Doppler shift of the spectrum of Chalawan.After the discovery of the first extrasolar planet around a Sun-like star, Dimidium, astronomers Geoffrey Marcy and R. Paul Butler searched through their observational data for signs of extrasolar planets and soon discovered two