2. When I buy my first telescope, will it be complete, or will I have to buy additional items to make it work?
Most telescopes marketed to beginners are complete systems, ready for the sky as soon as you unpack them and perform whatever setup procedures the manufacturer recommends. Some high-end models are sold as “optical-tube assembly only” versions. This means what it says: All you’re purchasing is the optics in the tube — no mount, tripod, or accessories.
Refractors usually need a star diagonal because of their design. A star diagonal bends the light from your target object 90°, so without one, you find yourself in some awkward positions when you’re observing objects high in the sky. The star diagonal fits into the telescope’s focuser, and the eyepiece fits into the star diagonal. Most manufacturers that provide complete refractor telescopes include a star diagonal.
3. I’m interested in observing, but I don’t know which scope to buy. What should I do first?
Your first step should be to learn all you can about telescopes: what types are available, what manufacturers sell them, and what words describe them. Page through the ads in each issue of Astronomy magazine, and you’ll see a range of what’s available.
For each telescope that interests you, visit that manufacturer’s website. When you’re finished reading this article, refer back to recent issues of Astronomy and carefully read telescope reviews (subscribers can read them online in the Astronomy.com Equipment Review Archive). You may not understand everything discussed in each review, but you’ll get a taste of telescope terminology. By doing this, you’ll learn what’s important to observers when they use a telescope. You’ll get a feel for optical and mechanical quality, ease of use (including portability), extra features, and — perhaps most importantly — which objects the telescope excels on.