An important channel of communication in many scientific fields is “Preprints.” The Astronomical Community uses this method very effectively for speedy communication. One of the main reasons for the prevalence of this practice in Astronomy is to reduce the time gap between the submission of an article and its actual publication in a scientific journal. Preprints are circulated by Astronomers among their colleagues. Libraries receive preprints either from authors or from institutions at which the authors are working.