HORUS is a high-resolution cross-dispersed echelle spectrograph proposed as visitor instrument for GTC. It is designed taking advantage of many of the optical elements from the Utrech Echelle Spectrograph, in operation on the 4.2m William Hershel Telescope between 1992 and 2001. With a resolving power of R~50,000 and broad wavelength coverage (380-420 nm contiguous and partial to 800 nm), HORUS aims at measuring the chemical compositions
of stars and nebulae, in the Milky Way and nearby galaxies, for studies of the origin of the chemical elements and galactic archaeology. The light gathering power of GTC and HORUS will allow the spectroscopic study of transiting exoplanets and the chemical analysis of globular clusters in galaxies of the local group. Using simultaneous wavelength calibration and enclosed in a vacuum chamber with active thermal control, HORUS will be able to detect
and characterize the orbits of planets with intermediate and low masses. Because most of the components are already in hand, HORUS requires only a modest investment of funding and time.