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About UIT

The Ultraviolet Imaging Telescope (UIT) was a shuttle-borne instrument used to obtain ultraviolet images of astronomical sources over a wide field of view. It was part of the ASTRO payload complement of three co-mounted instruments that flew in December 1990 and March 1995 as Space Shuttle missions. UIT was a project of the Laboratory of Astronomy and Solar Physics (LASP) at NASA's Goddard Space Flight Center. The Principal Investigator was Theodore P. Stecher.

UIT consisted of an f/9 Ritchey-Chretien telescope with an aperture of 38 cm. Two detectors covered the near-ultraviolet and far-ultraviolet wavelength ranges from 1200 to 3300 A. Six filters were available for each camera. Magnetically focussed two-stage image intensifiers produced images that were recorded on 70 mm film (Kodak IIa-O). The resulting images cover a 40 arcmin field of view, with a resolution of 3 arcsec. For comparison, the Wide Field Camera #2 on HST has much smaller field of view, 2.5 arcmin x 2.5 arcmin, with a higher resolution of about 0.1 arcsec. UIT could therefore obtain ultraviolet imaging of much larger, more extended objects, than HST. In addition, a diffraction grating was used for full field low resolution spectroscopy. The film images were digitized, linearized and flat fielded through a standard reduction system.

During the ASTRO-1 mission, 361 near-UV and 460 far-UV images were obtained for 66 targets. During the ASTRO-2 mission, 758 far-UV images were obtained for 193 targets. The near-UV camera failed at launch so no images were obtained with that camera. The images were obtained of a wide variety of extended astronomical sources. These include reflection nebulae, supernova remnants, globular clusters, spiral galaxies, dwarf galaxies, and clusters of galaxies.

Further details about UIT may be obtained from The Ultraviolet Imaging Telescope: Instrument and Data Characteristics, an article written by UIT mission personnel describing the design, operation, data reduction, and calibration of the instrument.

Example of a UIT Image
UIT Image of Messier 101
from UIT Photo Gallery