دانلود کتاب The Observer's Sky Atlas: With 50 Star Charts Covering the Entire Sky

The Observer's Sky Atlas is a wonderful little atlas in concept and, for the most part, in execution. The book was written by a professional planetary astronomer and offers useful star charts on odd numbered pages and tables of information on the even numbered facing pages about the objects shown on the charts. Additionally, the charts contain exploded views of those areas of the sky that contain the objects listed. The exploded areas shown dimmer stars near the objects, and this allows for easier spotting through a finder scope or the telescope, both of which will show stars much fainter than can be see with the naked eye. The charts also have reference numbers to direct the observer to other charts in the book featuring areas of the sky adjacent to the area under observation. This feature makes for quick navigation through the atlas. Additional features include an informative introduction with basic observing information and explanations about the charts and tables in the atlas, a key to the star charts for quickly finding the right page, an almanac containing a list of meteor showers, a lunar calendar and planetary opposition dates through 2018, and a glossary.I do many public and school star parties with my astronomy club, and this little atlas is a very handy tool. It focuses on the brighter objects most suitable for viewing with smaller telescopes (mine is a 6-inch) and the best objects for showing folks at star parties. The charts outline the constellations and so may be used as planispheres to help people identify star patterns and the location of the objects being viewed relative to those patterns. Moreover, the facing pages contain information that answers those commonly asked questions such as, "how far away is that?" This book has a permanent place among my observing references, and its small size makes is very portable.The reason I gave the book four stars, though, has to do with the binding. For some inexplicable reason, to me at least, the publisher decided not to use a spiral binding. I can only guess that it's a cost issue. Therefore, the book will not lie flat when open. After one refers to the charts and then turns back to the telescope, the book flops shut. When observing, one typically goes back and forth between the telescope and the atlas, especially if star hopping to find an object. Using an atlas that will not stay open if not held is exceedingly annoying. Of course, one can always carry a bookmark or turn the book over to keep the place, but that should not be necessary. Why any publisher of an astronomy field-reference would omit a spiral binding is a mystery to me.On a final note, this book seems to be similar in format to Objects in the Heavens, by Peter Birren. I have not seen that book, but the description on Amazon leads me to that conclusion. Birren's book is spiral bound.