The image data available through this site consist of telescopic images of the night sky obtained with a 0.9-meter telescope on Kitt Peak in Arizona. They have a scale of approximately one arcsecond per pixel and an exposure time of a little over 2 minutes. Limiting magnitude varies according to seeing, weather, exposure time, and instrument parameters, but can be as faint as V magnitude 21.5. The full-width at half maximum (FWHM) of star images varies from 1.2 to 4 arcsec. The spectral bandpass is either that of an unfiltered thinned, back-illuminated CCD, or that of the CCD filtered by a Schott OG-515 filter that passes wavelengths longward of 515 nanometers, depending on the epoch of the observations. Typically three observations of a given area of sky are made in the span of an hour and a half. Regions may be reobserved in this way on time scales of days, weeks, months, and years.
In 2002-2003, the drift-scanning 0.9m telescope was redesigned with new optics and a mosaic CCD system, changing operations to stare mode. The images produced by this system can be viewed by the public in near real time through our FMO Project. The mosaic FMO project was funded by the Paul G. Allen Charitable Foundation. All image dimensions are 1.7 degrees by 1.9 degrees. Sky coverage by the mosaic system is offered through the 'Mosaic Sky Coverage Data' link below:
Mosaic Sky coverage Data