Celestron 31056 - Manual

Introduction • 7 FAMILIAR WITH THE CORRECT OPERATING PROCEDURES OF YOURTELESCOPE. NEVER USE AN EYEPIECE SOLAR FILTER OR A HERSCHELW E D G E S O L A R F I L T E R . I N T E R N A L H E A T B U I L D - U P I N S I D ETHE TELESCOPE CAN CAUSE THESE DEVICES TO CRACK ORB R E A K . NEVER POINT YOUR TELESCO...

8 • The C150-HD A S S E M B L I N G Y O U R N E W T O N I A N T E L E S C O P E This section covers the proper assembly instructions for your G-8N and C150-HDreflecting telescope. These telescopes are Newtonian reflector that utilize mirrorswith specific focal length s . The telescope comes on the G...

The G-8N • 11 The tripod comes fully assembled with the metal plate, called the tripod head, thatholds the legs together at the top. In addition, the brackets that support the acces-sory tray are also attached to the tripod. Stand the tripod upright and pull the tripod legs apart until the leg brace...

The G-8N • 13 The equatorial mount allows you to tilt the telescope ’ s axis of rotation so that you can track the stars as they move across the sky. The CG-4 and CG-5 mounts areGerman equatorial mounts that attache to the tripod head (i.e., metal plate on thetripod). On one side of the plate there ...

14 • The C150-HD Attaching the R.A. Slow Motion Knob With the mount securely in place, you are ready to attach some of the accessories(the telescope tube will be added last). Start with the Right Ascension (R.A.) slowmotion knob. The R.A. slow motion knob allows you to make fine pointingadjustments ...

The G-8N • 15 Attaching the Declination Slow Motion Knob Like the R.A. slow motion knob, the DEC slow motion knob allows you tomake fine pointing adjustments in the direction the telescope is pointed. The DEC slow motion knob attaches in the same manner as the R.A. knob. The shaftthat the DEC slow m...

16 • The C150-HD Attaching the Counterweight Bar and Counterweight The last item to be mounted before the telescope tube is the counterweight barand counterweight. Used to balanced the telescope, the counterweight bar attachesto the opposite side of the mount as the telescope. To install the counter...

The G-8N • 17 Before you attach the optical tube, fully tighten the right ascension and declinationclamps. This will prevent the telescope from moving suddenly once attached to themount. 1 Locate the mounting bracket from the box containing the equatorial mount head. 2 Attach the mounting bracket to...

18 • The C150-HD Before you attach the optical tube, make sure that the declination and right ascensionclamps are tight. The optical tube attaches to the mount via two rings that aremounted on the tube of the telescope. To mount the telescope tube: 1. Loosen the knobs on the side of the rings. This ...

The G-8N • 19 The G-8N lens cover has a 1-1/2" cap covering an aperture stop that is offset fromthe center. To utilize the aperture stop, leave the telescope cover on the front of thetube and remove only the small aperture stop cap from the front of the cover. This isuseful when observing very b...

20 • The C150-HD The telescope should also be balanced on the declination axis to prevent anysudden motions when the DEC clamp is released. To balance the telescope inDEC: 1. Release the R.A. clamp and rotate the telescope so that it is on one side ofthe mount (i.e., as described in the previous sec...

22 • The C150-HD The entire telescope and mount is light enough to pick up and carry outside for acasual observing session. If, however, you want to transport your telescope to aremote observing location, you must partially disassemble it. Here ’ s how: 1. Remove the telescope from the equatorial mo...

The G-8N • 23 To install the finderscope onto the telescope you must first mount the finderscopethrough the finder bracket and then attach it to the telescope. Toward the front ofthe telescope tube, near the focusing assembly, there is a small bracket with a setscrew in it. This is where the finders...

26 • Telescope Basic T E L E S C O P E B A S I C S Once your telescope has been fully assembled and the accessories attached,you are ready to take a look. This section deals with basic telescope operation. The Newtonian optical system produces an upside down image. This willonly affect your terrestr...

Telescope Basics • 27 To focus your telescope, simply turn the focus knob located directly below theeyepiece holder (see figure 2-13). Turning the knob clockwise allows you tofocus on an object that is farther than the one you are currently observing.Turning the knob counterclockwise from you allows...

28 • Telescope Basic Accurate alignment of the finder makes it easy to find objects with the telescope,especially celestial objects. To make aligning the finder as easy as possible, thisprocedure should be done in the daytime when it is easy to find and identify objects.The finderscope has a spring-...

Telescope Basics • 29 With the telescope fully assembled and all the accessories attached you areready for your first look. Your first look should be done in the daytime when itis easier to locate the locking clamps and slow motion adjustment knobs. Thiswill help to familiarize you with your telesco...

30 • Telescope Basic Nighttime Observing Looking at objects in the sky is quite different than looking at objects on Earth.For one, many objects seen in the daytime are easy to see with the naked eyeand can be located by using landmarks. In addition, objects on the ground arestationary, or at least ...

Telescope Basics • 31 As implied in the previous section, you can change the power of yourCelestron telescope just by changing the eyepiece (ocular). To determine themagnification for your telescope, simply divide the focal length of the telescope(1000mm) by the focal length of the eyepiece you are ...

32 • Astronomy Basics A S T R O N O M Y B A S I C S This section deals with observational astronomy in general. It includes infor-mation on the night sky, polar alignment, and using your telescope for astro-nomical observations. In order to help find objects in the sky, astronomers use a celestial c...

Astronomy Basics • 33 Like the Sun, the stars also appear to move across the sky. This motion is causedby the Earth ’ s rotation. For observers in the northern hemisphere, all stars appear to move around the north celestial pole. For observers in the southern hemisphere,all stars appear to move arou...

34 • Astronomy Basics Figure 4-3 When the telescope’s axis of rotation is parallel to the Earth’s axis, stars viewedthrough the telescope appear stationary when using a motor drive. In order for the telescope to track the stars it must meet two criteria. First,you need a drive motor that will move a...

Astronomy Basics • 35 For each hemisphere, there is a point in the sky around which all the otherstars appear to rotate. These points are called the celestial poles and arenamed for the hemisphere in which they reside. For example, in the northernhemisphere all stars move around the north celestial ...

36 • Astronomy Basics Latitude Scales The easiest way to polar align a telescope is with a latitude scale. Unlikeother methods that require you to find the celestial pole by identifying certainstars near it, this method works off of a known constant to determine how highthe polar axis should be poin...

Astronomy Basics • 37 Pointing at Polaris This method utilizes Polaris as a guidepost to the celestial pole. Since Polarisis less than a degree from the celestial pole, many amateurs simply point thepolar axis of their telescope at Polaris. Although this is by no means a perfectalignment, it is clos...

38 • Astronomy Basics D e c l i n a t i o n D r i f t This method of polar alignment allows you to get the most accurate alignmenton the celestial pole and is required if you want to do long exposure deep-skyastrophotography through the telescope. The declination drift method requiresthat you monito...

Astronomy Basics • 39 Polar Alignment Finders There are two finders specifically designed for polar alignment that can be usedwith the CG-4 and CG-5 mounts. These finders can be purchased as optionalaccessories for the C150-HD and G-8N. The first finder, known as the 7x50 Polarisfinder (#51614), is ...

40 • Celestial Observing C E L E S T I A L O B S E R V I N G With your telescope set up, you are ready to use it for celestial observing.This section covers visual observing of both solar system and deep-skyo b j e c t s . In the night sky, the Moon is a prime target for your first look because it i...

Celestial Observing • 41 O b s e r v i n g D e e p - S k yO b j e c t s Although overlooked by many amateur astronomers, solar observation is bothrewarding and fun. However, because the Sun is so bright, special precautionsmust be taken (always use the proper solar filter) when observing our star so...

42 • Celestial Observing Using the Setting Circles Once the setting circles are aligned you can use them to find any object with knowncoordinates. 1 . Select an object to observe. Use a seasonal star chart or planisphere tomake sure the object you chose is above the horizon. As you becomemore famili...

Celestial Observing • 43 S t a r H o p p i n g You can use your setting circles to find these objects (as described earlier inthis manual) or try star hopping. Star hopping is done by using bright stars toguide you to an object. Here are directions for two popular objects. The Andromeda Galaxy, M31,...

44 • Celestial Observing Star hopping may take some getting used to since you can see more stars throughthe finder than you can see with the naked eye. And, some objects are not visiblein the finder. One such object is M57, the famed Ring Nebula. Here ’ s how to find it: 1 . Find the constellation o...

Celestial Observing • 45 Viewing conditions affect what you can see through your telescope during anobserving session. Conditions include transparency, sky illumination, and seeing.Understanding viewing conditions and the affect they have on observing will helpyou get the most out of your telescope....

Celestial Photography • 47 C E L E S T I A L P H O T O G R A P H Y After looking at the night sky for awhile you may want to try photographing it.Several forms of celestial photography are possible with your Celestron telescope.The most common forms of celestial photography, in order of difficulty a...

48 • Celestial Photography Short exposure prime focus photography is the best way to begin recording celestialobjects. It is done with the camera attached to the telescope without an eyepiece orcamera lens in place. To attach your camera, you need the T-adapter and a T-Ringfor your specific camera (...

Celestial Photography • 49 The exposure times listed here should be used as a starting point. Always makeexposures that are longer and shorter than the recommended time. Also, trybracketing your exposures, taking a few photos at each shutter speed. This willensure that you will get a good photo. If ...

Maintenance • 51 T E L E S C O P E M A I N T E N A N C E After you have set up your telescope and started using it, there are a few things toremember for future reference. To minimize the need to clean your telescope, replace all lens covers once youhave finished using it. Since the front of the tel...

52 • Maintenance Prior to collimating the primary mirror holder, locate the three (3) screws on the endplate at the end of the tube. Unthread the three screws and remove the plate from theend of the tube. Under the end plate there are three (3) sets of two (2) screws. Theshorter Allen screws push th...

Optional Accessories • 53 O P T I O N A L A C C E S S O R I E S The following is a partial list of optional accessories available for your CelestronC150-HD and G-8N. Barlow Lens - A Barlow lens is a negative lens that increases the focal length of a telescope. Used with any eyepiece, it doubles the ...

60 • Astronomy Books FOR FURTHER READING The following is a list of astronomy books that will further enhance your understanding of the night sky. Thebooks are broken down by classification for easy reference. Astronomy Texts Astronomy Now ...............................................................

CELESTRON ONE YEAR WARRANTY A. Celestron warrants this telescope to be free from defects in materials and workmanship for one year. Celestron will repair or replace such product or part thereof which, upon inspection by Celestron, is found to be defective in materials or workmanship. As a condition ...