This thesis presents accurate analyses of the spin-orbit angle for many remarkable transiting exoplanetary systems, including the first measurement of the Rossiter-McLaughlin effect for a multiple transiting system.

The author presents the observational methods needed to probe the spin-orbit angle, the relation between the stellar spin axis and planetary orbital axis. Measurements of the spin-orbit angle provide us a unique and valuable opportunity to understand the origin of close-in giant exoplanets, called "hot Jupiters."

The first method introduced involves...