General Features Optical Design: Refractor Aperture: 70mm(2.75in) Focal Length: 400mm(15.7in) Focal Ratio: F5.7 Eyepiece1: 25mm(0.98in) Magnification1: 16X Eyepiece2: 10mm(0.39in) Magnification2: 40X Max Magnification: 120 Finderscope:[…]
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Revised Fourth Edition: updated for use through 2025. The first three editions of NightWatch sold more than 600,000 copies, making it the top-selling stargazing guide[…]
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A star-filled sky is as mysterious as it is sublime. What are we looking at? How far away and from when?! How do I tell[…]
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General Features Optical Design: Refractor Aperture: 80mm(3.2in) Focal Length: 400mm(15.75in) Focal Ratio: F5 Eyepiece1: 25mm(0.98in) Magnification1: 16X Eyepiece2: 10mm(0.39in) Magnification2: 40X Eyepiece3: 5mm(0.196n) Magnification3: 80X[…]
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For a generation, Astronomy: A Self-Teaching Guide has introduced hundreds of thousands of readers worldwide to the night sky. Now this classic beginner’s guide has[…]
Read moreWelcome to the first episode of Crash Course Astronomy. Your host for this intergalactic adventure is the Bad Astronomer himself, Phil Plait. We begin with[…]
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