Other note-worthy research the "South African Astronomical Observatory" has achieved using SALT include the discovery of a class of stars known as "polar", or a pair of stars. The "polar" binary star system, where a compactor star called a "white dwarf" whose volume has shrunk about one millionth of a star like our sun. Studies using SALT concluded that these polar binary star systems take only an hour and a half to complete an orbit. Also, the SALT telescope allows scientists to study the rapid brightness changes in exotic stars.