Hale telescope. Observer sitting at the prime focus of the Hale telescope, which is housed at the Palomar Observatory in California, USA. This reflector telescope was named after the astronomer George Ellery Hale when it was completed in 1948. At about five meters (200 inches), it is the second largest single fixed mirror telescope in the world. Many important advances in astronomy took place here, such as the first observation of a brown dwarf star. The dome sits at an elevation of 1867 meters within the Palomar mountain range.