Getting Started

The Ultraviolet Imaging Telescope (UIT) was the imaging component of the three ASTRO ultraviolet telescopes that flew on Space Shuttle missions in December 1990 and March 1995. The instrument was well suited to the study of large extended objects: globular clusters, reflection nebulae, supernova remnants, galaxies, and clusters of galaxies. The large field of view and ultraviolet bandpass make the UIT images a unique dataset, complementary to other imaging instruments such as HST's WFPC.

The MAST holdings include over 1500 ultraviolet images of 243 targets. The field-of-view is circular with a diameter of 40 arcmin and a nominal resolution of 3 arcsec. Two cameras, each with 6 filters, provide a range of effective wavelengths and bandpasses in the near- ("A" camera) and far-ultraviolet ("B" camera). Of these, the broad-band A1, B1 and B5 filters were used for most of the images. The images were recorded on Kodak IIa-O film, then developed and digitized. The data were flat-fielded, linearized, and when possible absolutely calibrated, geometrically rectified, and rotated to create fully reduced images with orthogonal RA and Dec axes and uniform plate scale.

The search form may be used to select data from the UIT catalog by object name, coordinates, filter, date of observation, etc. In addition, users may browse the Catalog or download the images using anonymous ftp.

The images are archived as FITS files. Several versions of the images are available as captured at various stages during the image processing. Not all the images could be fully calibrated, so users should check the file names (see Data Products) and FITS headers to determine what reduction and calibration steps were applied.