The WISE Preliminary Release includes data from the first 105 days of WISE survey observations, 14 January 2010 to 29 April 2010, that were processed with initial calibrations and reduction algorithms. Primary release data products include an Atlas of 10,464 calibrated, coadded Image Sets, a Source Catalog containing positional and photometric information for over 257 million objects detected on the WISE images, and an Explanatory Supplement that provides a user's guide to the WISE mission and format, content, characteristics and cautionary notes for the Release products. Ancillary release products include an archive of over 754,000 Single-exposure Image sets and database of over 2.2 billion source extractions from those images, and moving object tracklets identified as part of the NEOWISE program (Mainzer et al. 2011).
