دانلود کتاب Hunting and Imaging Comets

Of all the objects visible in the night sky, it is the brightest comets that have most fascinated amateur astronomers and alarmed the human population. No other objects can stretch as far across the sky as the tail of a truly great comet, or be as easily visible as a zero-magnitude ‘broom star.’ In recent times amateur astronomers have made some surprising discoveries, including the comets Hale-Bopp and Hyakutake, while also playing a critical role in detecting the comets that hit Jupiter in 1994 and 2009. It was also an amateur astronomer that first spotted the dazzling October 2007 outburst of 17P/Holmes. Discovering a comet has always been the greatest prize for the amateur astronomer – the chance to truly “write your name across the sky.” Remarkably, despite routine professional CCD surveys, many amateurs worldwide still discover comets in the 21st century. In Hunting and Imaging Comets Martin Mobberley, an active comet imager himself, explains how non-professionals have achieved such success. This book describes in precise detail how amateur astronomers can find comets and capture spectacular images of them using modern telescopes, CCDs, and digital SLRs. Mobberley also explains how computer software can be used to measure the positions and brightness magnitudes of comets to a professional standard and how to submit those scientific results to the astronomical community. If you want to search for new comets, or simply observe known ones, this is the book for you!