The Astrophysics Concentration and new Secondary Field in Astrophysics offer small class sizes, the highest faculty-­to­-student ratio of the physical science departments, and the opportunity to travel to remote astronomical observatories. Students often pursue a joint concentration with either Physics or Earth & Planetary Sciences. The Center for Astrophysics | Harvard & Smithsonian, located at 60 Garden Street opposite the Radcliffe Quadrangle, is one of the world's great centers for research in astrophysics, with over 350 scientists and powerful astronomical observatories in Arizona, Chile, Hawaii, and in space. Undergraduate students interested in participating in either term-­time or summer research are encouraged to contact the Director of Undergraduate Studies to discuss the numerous opportunities, which range from the hunt for planets orbiting nearby stars to the quest to understand the Big Bang and the accelerating Universe.