Last Update: 2019-02-12

Getting Started In Astronomy

by Tom Bruce
 

Disclaimer:
Astronomy is a wonderful activity .. whether or not you will ever develop this interest.  No matter where you are in the world, look up, and the same stars are always there and in the same place -- count on it!  Astronomy is also a personal activity. Each person starts it in his/her own way, listen to others, but  still pursue your own interests.

Most beginners begin by "tinkering around" with sky charts and scopes of some sort. They like to go outside and try to make some sense out of the patterns of stars they see in the sky. Later as their experience and education develops, they start building their own devices or start saving enough cash to buy a small telescope. There is always a question of buying equipment and how much to spend .. and then .. perhaps, losing interest later. I have a comment about this: buy the best you can afford and keep it well and protected. Your interests will change but there is a good chance you will want to open up this interest again .. even for a short time.  The pithy notes, below are mine !

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• For beginners .. and for a short time, I suggest you stay away from telescopes, altogether, and get a good set of binoculars (7 x 50 or 8 x 60) a good set of sky charts and/or a planetary program (StarCalc, listed below). There is much to learn about basic astronomy that will make your efforts more enjoyable. 

  In any case, never- ever consider buying a "box-store" type of telescope.
   

• Take as an example - a " 7x50 " pair of binoculars: The first number tells you the magnifying power and the 2nd number is the diameter (in mm) of the front lens. Now the size of the front lens --called the "objective lens"-- tells you how much light this device will capture.  But perhaps more important, the 2nd number also indicates the ability of the scope to resolve fine detail on the objects you are viewing.  So in generally, chose a pair of binoculars with the biggest 1st and 2nd numbers that you can afford.  But ... there are other considerations:
   

  • Rules
    • The greater the 1st number (magnification), the harder it is to hold the scope still .. but ..
    • The greater the 1st number (magnification), the dimmer the faint object will appear
       
    • The greater the 2nd number (diameter), the more light will be captured .. but ..
    • The greater the 2nd number (diameter), the finer the detail you will see on the object you are viewing
       
    • So .. it may be a little difficult to balance magnification vs brightness vs resolution vs cost .. so I would try the binocular, before buying. (say compare 7-50s to 16-60s)
       
    • Aside: Also. if you divide the 2nd number by the 1st number then you get the diameter of the cone of light entering the pupil of your eye (ideally, 7mm for night time observing). 
       
    •  With 7-50s You should be able to see the 4 moons of Jupiter and the rings of Saturn with either of these binoculars depending on how clear the sky is .. but ..it will be difficult.  

• The same argument holds for a telescopes, however a nice "sweet spot" would be a 13" f/7 telescope for the experienced amateur. Where, the "f/7" stands for focal ratio (focal length/mirror diameter).  Large focal ratios indicate higher magnifications with decreasing object brightness .. same as your camera. In addition, costs are greater with telescopes and you must ALSO add the cost of the mount and drive and instrumentation, if this applies.
   
   
• Again, I would not recommend a telescope until you become familiar with basic astronomical geometry and terms that are routinely used. 
   
• Picking a scope:
  • If cost is critically important, then I would contact a local Astronomy club about used-scopes; or through local manufacturers in your area; or perhaps publications (magazines, news letters) that would list used telescopes. Try eBay.
     
    • Aside: On eBay you can still find a russian made small telescope called The "Rubinar 1000mm."  This is a an excellent scope .. but you would still have to add a mount and drive that can be difficult if not impossible without some experienced help.  This scope can also be used as a telephoto lens for a camera ..but again  with experienced help . Expect to pay $200-$400 but ask about the condition
       
    • Aside: ignore any scope that has scratches or sleet marks across the glass (optical) surfaces.  If it has dust, only, then it can be cleaned by letting warm soapy water wash across the coating and then let dry. 
       

    • Under no circumstances .. ever .. touch any optical surface of a mirror or lens with you hands or other material.
       

    • Always ask the sales representative if they have used/refurbished telescopes for sale .. and their condition.
       
• If you are looking for a complete but inexpensive telescope then look at iOptron's Smart Cube telescopes or others. I believe it has a 4" diameter mirror, but also has a mount and drive that sets itself and can be put away in a box and stored for use, later. This scope is operated with a control box that can be used to "GOTO" astronomical objects (planets, stars etc) directly. A small light camera could be added, later.  
   
• If you still want to go for a larger but still inexpensive push-along telescope then look at a "Dobson 8" to 10" telescope.  Try to get the f-ratio as large as possible say, f/10 .. but manufactures seem to build telescopes with an all around f-ratio around f/4.5.  The diameter of the mirror is very important for user satisfaction.  The larger the diameter of the mirror, the finer the detail that you can see .. and of course a larger diameter mirror captures more light. Note: "Dobson" is a generic name for a type of Alt-Azimuth telescope.  What you find: Coulter's Odyssey Dobson Telescope.  Coulter made excellent and inexpensive Dobson types of telescope systems but I am not sure if they are still in business .. again try eBay.
   
• There are very good reasons for buying any good telescope but it is hard to beat what you can now find on the web or in magazines (Sky and Telescope, Astronomy etc) especially if you only observe now and then or are not working on a personal project.  England has many excellent scope makers. In America telescope makers are becoming a dying breed.

• Next I recommend that you download the free astronomy software package called StarCalc developed in Russia at: