{"product_id":"the-night-sky-observers-guide-sring-summer-2","title":"The Night Sky Observers Guide: Sring \u0026 Summer: 2","description":"\u003cp\u003eAmateur astronomers today are exceptionally fortunate to be living in an era when high quality  and very large  optics are so affordable. In the first half of the 20th century the telescope deluxe for the amateur was the 6-inch refractor. However  such telescopes were so expensive that very few amateurs could afford them: the majority of stargazers had to content themselves with instruments in the 60mm range. Consequently  most observing guides published during that time emphasized double and multiple stars  with honorable mention for variable stars and planetary nebulae  objects which do well in long focal length refractors. Webbs 1858 Celestial Objects for Common Telescopes and Olcotts 1936 Field Book of the Skies were not superceded for so many decades simply because the average amateur instrument did not dramatically improve during the century after Webb. By the 1950s the mass-produced or homemade 6-inch parabolic mirror brought medium-sized optics into the price range of the ave\u003c\/p\u003e","brand":"My Store","offers":[{"title":"Default Title","offer_id":44983727030325,"sku":"ByrdShop_0943396603","price":69.25,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0627\/8139\/0901\/files\/9780943396606.jpg?v=1770807806","url":"https:\/\/atxbooks.com\/products\/the-night-sky-observers-guide-sring-summer-2","provider":"ATX Books","version":"1.0","type":"link"}