Library Telescopes

Leon County has a limited number of 130mm Newtonian Reflector table top telescopes available to check out as part of the "Library of Things" program.  The telescopes are the Astronomers Without Borders (AWB) One Sky model. These are high-quality, robust telescopes with a unique collapsible truss-tube that makes them easy to store and transport.  They can be checked out for up to two weeks using your regular library card.  You get the scope, two eyepieces, the finder, a collimation cap, and a tool, all in a handsome canvas duffle bag for transport and storage. 

Visit the Leon County Library to learn how to borrow a telescope.  These telescopes are a great way to take a telescope for a "test drive" before deciding to purchase your own.  The telescopes are not toys -- they are serious observing tools.  They will have a learning curve, like any complex tool.  See the tips below, and give yourself permission to take the time you need to get full enjoyment out of this tool.

This section is for folks who have checked out, or are considering checking out, a Library Telescope.  It answers some commonly asked questions about these wonderful instruments.  Here are some quick links for your reference:

• AWB One Sky Manual:  The Library Telescope will include a hard copy of this pdf manual. You can get it here first  so you'll know what to expect.

• A Review of the AWB One Sky Telescope (YouTube):  9 minute video does an excellent job familiarizing you with how to set up the Library Telescope.

• The AWB One Sky Page on the AWB Store Site:  A lot of good background information about the Library Telescope

• How to Align the Red Dot Finder (YouTube): You must install and align the red dot finder before you can use the telescope. This video from Celestron describes how to do it.

Here are some tips that can make using the telescope easier (and more fun!) They are listed in more or less priority order.

1. Give Yourself Some Time:  A telescope is not like a pair of binoculars that you can just pull off a shelf and start using. It's more like an airplane that has to be preflighted. If you've never used one of these scopes before, allow an hour or so to set it up and get familiar with it, before ever trying to use it to view the night sky, even if you are familiar with other telescopes.  You'll just have more fun if you're not trying to figure everything out "on the fly", possibly with your kids or other people looking over your shoulder.  Each time you use the scope, you'll need to allow a few minutes to go through at least some of the steps below. 

2. Balance the Telescope:  The Library does this for you, but it may have gotten bumped or fiddled with.  Check the balance of the telescope to be sure it can be easily controlled, as follows: 

   • Extend the telescope to its full length and loosen the Tension Control Knob (see the manual p.2 for a parts diagram). Insert the 25mm eyepiece. 

   • The telescope should be perfectly balanced so it stays wherever you point it.  If it wants to droop or rise by itself, loosen the Dovetail Locking Screw just enough to let you slide the telescope back and forth on the dovetail rail, until it is balanced.  

   • Once balanced, tighten the The Dovetail Locking Screw, and adjust the Tension Control Knob to your liking. The scope should stay where you point it and move with only a slight pressure ("fingertip pressure".)   

   • You should only have to do this once, if at all. Once balanced, don't change it!

3. Check Collimation: The Library also does this for you, but it can change if the telescope is jostled and, well, figure the odds of that happening!  "Collimation" is just a fancy word that means the two mirrors in the telescope are aligned with each other. The big mirror at the bottom with a dot in the middle is the "primary"; the smaller one at the top is the "secondary."  A reflecting telescope, like this one, has to be tuned before each use, sort of like a guitar.  The instructions for collimating are in the manual. Just follow them and you'll be fine.  Note that you don't have to construct a collimation cap -- the Library provides a very nice collimation eyepiece with the kit.  Also, note you should only need to adjust the secondary mirror once, if at all.  This is usually done for you by the Library.  Leave a few minutes to adjust the primary, though, at the beginning of each observing session. See below for an Advanced Technique using only a star to collimate your telescope "on the fly" while observing, once the initial collimation is done.

4. Align the red dot finder:  Once the scope is balanced and collimated, line up the red dot finder. There is a video above showing how to do this. It's best done during the day or directly after sunset, using a distant fixed object like a sign or pole or tree top.  Find the object using the 25mm eyepiece and lock the telescope into position. Then align the red dot finder. Once aligned, take a few practice shots at other distant objects to be sure the you can acquire objects using the finder.   

5. Let the mirror cool down:  When you take the scope outside, the mirror will take several minutes, maybe up to half an hour, to reach thermal equilibrium. You can use it during this time, but you may notice the view gets better as the mirror cools down.  If possible, set the telescope outside a half-hour or so before you plan to observe, so the mirror will be ready when you are. 

6. Use the 25mm Eyepiece First and Last: It's good practice to start and end your observation of every object using the low power 25mm eyepiece.  This eyepiece is designed to have the wider field of view (compared to the shorter eyepiece) specifically to help find objects. Get in the habit of putting it back in and focusing it before moving on to another target.  It's very difficult to find things using the high powered, shorter eyepiece. 

7. Break down with the same care you set up:  At the end of your session, put the caps back on the eyepieces and put all the eyepieces and tools back in their bag.  Collapse the telescope and store it sitting upright on its base. This is how it is meant to be stored. Next time, you'll be able to get it out and use it much more quickly. 

8. Get Thee to Darker Skies:  Any telescope will show more when the sky is darker, for two reasons. First, the darker sky itself will reveal fainter stars and more details than a brighter sky. Second, your eyes will be able to dark-adapt better, allowing you to actually see fainter stars and more detail. And the Library Telescope is a perfect, portable observatory to take to dark sky locations at the beach or on a camping trip far from city lights! 

9. Have fun!  See below for some objects you might seek out with your Library Telescope.  The telescope will reveal fainter objects and much greater detail than your naked eye. It is lightweight, quick to set up (once the initial set up is done) and is a pleasure to use, when used properly.

TAS is in the process of upgrading the telescope equipment. Please use the following process to ensure your scope is stored safely for the next user:

1. Make sure the red dot finder is turned off

2. Put all the accessories in their places in the clear plastic case or accessories bag

3. Make sure the red dot finder is turned off, and leave it attached to the telescope

4. Turn the telescope tube so that the focuser and red dot finder are on the underside of the tube

5. Place the telescope in the bag with its feet down. If your bag has a wooden base installed, set the telescope on this base.

6. Put the accessories case and documents folder on the base of the telescope

7. Make sure the red dot finder is turned off

8. Pull the bag up around the telescope and zip it shut

9. Return the telescope to the check out counter of the library

The size and focal length of the Library telescope makes it a surprisingly versatile and portable tool.  The Library generously includes a Monthly Sky Chart (from www.skymaps.com )with your telescope to let you know what constellations and objects are up at the moment. Objects seen visually through a telescope will not look like the long-exposure photographs seen through the Hubble Space Telescope or even the amateur photos on the TAS homepage.  A camera is able to absorb far more light and color over a longer period of time than the human eye.  Visual objects tend to have little to no color; some will only appear as "smudges" at first. You will have to train your eye to look for the subtle details in diffuse objects like galaxies and nebulae.

The sky chart provided by the library is a great place to find items to seek out with your telescope. Here are some other things you can look for pretty easily, because they are visible also to the naked eye and will be easier to find.  Amateur astronomers normally use binoculars to pick out their targets first, then use the telescope to go in for a closer look.  Any binoculars you already own can be used!

Easier to Find

• The Moon:  The Moon looks fabulous in a telescope!  The best time to look is before or after a full moon, when the shadow line (the terminator) crosses the face of the Moon. The low angle of the sun will reveal a wealth of features to explore. 

• Planets: Saturn's rings will be clearly visible. You will able to see Jupiter's four Galilean moons as well as cloud bands.  At the right time, and with a little luck, you may be able to see polar ice caps on Mars and a little bit of surface detail. You will be able to what Venus go through her phases (just like the moon). 

• Star clusters: These groups of gravitationally-bound stars spilling across the night sky in your eyepiece have been compared to diamonds spilling on black velvet.  In Fall and Winter, look for M45 (the Pleaides), which is a naked eye cluster in the constellation Taurus, the Bull.  

• Galaxies:  The Andromeda Galaxy, in the constellation Andromeda, is visible to the naked under as a hazy patch, under very dark skies. It will fill the eyepiece of your telescope.  Look for an elongated smear of light.  The light hitting your eye is from another galaxy!  How cool is that?  

More Challenging to Find

Here are some objects that will require more skill (and probably binoculars) to find. The are not visible to the naked eye, so you'll need to know a little about the night sky and be able to follow a star chart or planetarium app. There is a Monthly Sky Chart included in your telescope kit, courtesy of the Library.  If you decided to stick with astronomy, you might invest in a more detailed star atlas, such as the Sky & Telescope Pocket Sky Atlas.

Planets:  Uranus is actually visible in a telescope, but you have to know exactly where to look. Use the internet or a planetarium app to determine where Uranus is right now. You are looking for a blueish "star" against the background of the other stars, that is not on any of the star charts.  That's about all the detail you can see, but most people have never seen Uranus at all!  It's worth a try.  Don't bother looking for Neptune -- it is beyond the reach of this small telescope. 

Asteroids: Yes, you can see asteroids and minor planets with this scope, if you know where to look!  Check a website or planetarium app for the positions of the minor planets Ceres and Vesta.  As with Uranus and Neptune, these will just appear as "star like points" and you'll have to find them based on the "which one of these doesn't belong" on the star charts method. This is exactly how these asteroids were originally discovered, so you'll be following in the footsteps of our astronomer ancestors!

Star Clusters, Galaxies, and other Deep Sky Objects:  All of the 110 Messier Objects are within reach of this telescope.  You'll need a good set of star charts or app, but these are well worth seeking out.  Charles Messier's Eighteenth Century "List of things to Avoid Looking at Because They Are Not Comets" has turned out to be the treasure box of amateur astronomy.  His objects include the most beautiful and interesting objects easily visible in a small telescope.  They include galaxies, nebulae, and star clusters all across the northern hemisphere (basically everything visible from the latitude of Paris, where Messier's observatory was located.) Here are just a few of the ones that will be visible in the Library telescope (if you can find them!)

• M44 The Beehive Cluster in Cancer

• M36, M37, and M38 in Auriga

• M21, M22, and M23 in Sagittarius

• M13 a Globular Cluster in Hercules

• M42 the Orion Nebula in Orion

• M41 open cluster in Canis Major

This is for users who have already done the basic collimation and want to try something a little more challenging. Some find this an easier way, in fact, to collimate a Newtonian reflector. 

Once the telescope is tuned up, with secondary and primary collimated and the red dot finder aligned, it will give good images.  However, sometimes as the mirror cools, the image may degrade a bit, or sometimes you may notice a bit of flare around the stars. You don't need to break out the collimation eyepiece to fix this.  

1. Point the telescope at a bright star, center it in the field, and put in the high power eyepiece.  Defocus the star so that you see a "bullseye" pattern (see the top of Page 8 in the manual for an example.) You are looking at the "Airy disk" of the star, and the dark spot near the middle is the shadow of the secondary mirror. Unless it is dead-perfect, you may want to re-center it, which is just another way of recollimating the telescope.  

2. While looking through the eyepiece, reach down and loosen the tall bolts that lock the primary into position, so you can easily turn the shorter collimation thumbscrews. Turn one of these a tiny bit and observe the effect on the defocused star. If it moved the shadow  of the secondary closer to center, turn it a little more. If not, turn it the other way! 

3. When you've exhausted the ability of that screw to help, use a different screw in the same way.  Work back and forth until you have recentered the shadow of the secondary.  Try to just use two screws, as much as you can.  Introducing that third screw can actually make things more complicated.  When you are done, you should have a perfectly centered "bullseye" star pattern. Retighten the three tall locking bolts. 

Many astronomers use this method, exclusively, for collimating their telescopes; other just to tweak the collimation as the night wears on.  As long as the secondary mirror is properly aligned, this is a perfectly acceptable, perhaps even preferable, way to collimate the primary.  You will probably find that everything looks even better after you've collimated your scope using only the stars. Somehow, that seems appropriate, doesn't it?