Prof Leeuw Lerothodi (CGS) and Dr Steve Crawford (SALT)
On March 26th, 2013, Dr Steve Crawford, the data manager at the Southern African Large Telescope, presented a College of Graduate Studies (CGS) seminar entitled “A Night in the Life of SALT”
As described by Dr Crawford, the Southern African Large Telescope (SALT) is the largest single optical telescope in the southern hemisphere and among the largest in the world. It has a hexagonal primary mirror array 11 metres across, comprising 91 individual 1.2m hexagonal mirrors.
SALT can detect the light from faint or distant objects in the Universe, a billion times too faint to be seen with the unaided eye – as faint as a candle flame would appear at the distance of the moon. The telescope and instruments are designed to operate from the near ultraviolet to the near infrared (320 to 1700 nm), and offer some unique or rare capabilities on a telescope of this size.
SALT collects light from astronomical objects and accurately focuses it to one of four selectable focii. From there the light proceeds into an optical instrument while the telescope tracks the relative movement of the object across the sky to maximise exposure time
Throughout the night, the SALT Astronomer and operator will do observations for a wide range of different projects ranging from Near Earth Asteroids to galaxies at the end of the Universe. Dr Crawford showed some early SALT results from a project done with Prof Lerothodi L. Leeuw, of the College of Graduate Studies, on very distant galaxies that are gravitationally lensed by closer galaxies that can be observed with SALT to determine their spectra, distances and geometry of their lenses. Do look out for other exciting results coming from SALT in the future; and, when in the Karoo near Sutherland, stop at the SALT Visitor Centre to learn more about SALT and its results.
