Celestron 31058 manual

C150-HD AND G-8N NEWT ONIAN INSTR UCTION MANU AL Models #31056 and #31058[...]

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T ABLE OF CONTENTS ▲ ▲ ▲ ▲ ▲ INTRODUCTION ................................................................................................................ .................................. 5 How to Use This Manual ......................................................................................................... ...................[...]

Observing the Moon ............................................................................................................. ........................ 4 0 Observing the Planets .......................................................................................................... ......................... 4 0 Observing the Sun ...............[...]

Introduction • 5 INTR ODUCTION Welcome to the Celestron world of amateur astronomy! Celestron has been providing amateur astronomers with the tools to explore the universe for more than a quarter of a century. The Celestron Newtonian telescope continues in this proud tradition. With a mirror diameter of 6", your C150-HD has almost 500 times [...]

6 • Introduction This manual is designed to instruct you in the proper use of your Celestron Newtonian telescope. The instructions are for assembly, initial use, long term operation, and maintenance. There are seven major sections to the manual. The first section covers the proper procedure for setting up your Celestron telescope. This includes s[...]

Introduction • 7 FAMILIAR WITH THE CORRECT OPERATING PROCEDURES OF YOUR TELESCOPE. NEVER USE AN EYEPIECE SOLAR FILTER OR A HERSCHEL WEDGE SOLAR FILTER. INTERNAL HEAT BUILD-UP INSIDE THE TELESCOPE CAN CAUSE THESE DEVICES TO CRACK OR BREAK. NEVER POINT YOUR TELESCOPE AT THE SUN UNLESS USING THE PROPER SOLAR FILTER. WHEN USING A SOLAR FILTER, ALWAYS[...]

8 • The C150-HD ASSEMBLING Y OUR 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-HD reflecting telescope. These telescopes are Newtonian reflector that utilize mirrors with specific focal length s . The telescope comes on the German equatorial mount, which when properly aligned and f[...]

The G-8N • 9 1. Finderscope 9. Tripod Leg Clamp 2. Finderscope Bracket 10. Leg Brace Assembly 3. Tube Ring 11. Counterweight 4. Piggyback Adapter 12. Counterweight Shaft 5. Latitude Scale 13. Equatorial Mount 6. Latitude Adjustment Screw 14. Focuser 7. Tripod 15. Eyepiece 8. Accessory Tray Figure 2-1 G-8N with CG-5 Equatorial Mount The G-8N 1 2 3[...]

10 • The C150-HD 1. FinderscopeBracket 9. Accessory Tray 2. Finderscope 10. Counterweight 3. Tube Ring 11. Counterweight Shaft 4. Primary Mirror (inside tube) 12. Declination Circle 5. Solw Motion Cables 13. Mounting Platform 6. Latitude Scale 14. Eyepiece 7. Latitude Adjustment Screw 15. Secondary Mirror 8. Tripod The C150-HD 1 2 3 5 7 8 4 9 10 [...]

The G-8N • 1 1 The tripod comes fully assembled with the metal plate, called the tripod head, that holds 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 assembly for the accessory tray is fully ext[...]

12 • The C150-HD There are three wing bolts that hold the accessory tray to the center leg brace. 1 . Locate the three wing bolts. 2. Place the accessory tray over the leg brace and position it so the thread holes in the accessory tray are above the slotted holes in the bracket. 3. Insert the wing bolts up through the slotted holes in the leg bra[...]

The G-8N • 1 3 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 are German equatorial mounts that attache to the tripod head (i.e., metal plate on the tripod). On one side of the plate there is an “ N ” which signifies north. This[...]

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.) slow motion knob. The R.A. slow motion knob allows you to make fine pointing adjustments in the direction the telescope is aiming (onc[...]

The G-8N • 1 5 Attaching the Declination Slow Motion Knob Like the R.A. slow motion knob, the DEC slow motion knob allows you to make 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 shaft that the DEC slow motion knob fits over is toward the top of the[...]

16 • The C150-HD Attaching the Counterweight Bar and Counterweight The last item to be mounted before the telescope tube is the counterweight bar and counterweight. Used to balanced the telescope, the counterweight bar attaches to the opposite side of the mount as the telescope. To install the counterweight bar: 1 . Retract the counterweight bar [...]

The G-8N • 1 7 Before you attach the optical tube, fully tighten the right ascension and declination clamps. This will prevent the telescope from moving suddenly once attached to the mount. 1 Locate the mounting bracket from the box containing the equatorial mount head. 2 Attach the mounting bracket to the tube rings so that the tappered (narrow)[...]

18 • The C150-HD Before you attach the optical tube, make sure that the declination and right ascension clamps are tight. The optical tube attaches to the mount via two rings that are mounted on the tube of the telescope. To mount the telescope tube: 1. Loosen the knobs on the side of the rings. This will allow you to slide the mount- ing rings t[...]

The G-8N • 1 9 The G-8N lens cover has a 1-1/2" cap covering an aperture stop that is offset from the center. To utilize the aperture stop, leave the telescope cover on the front of the tube and remove only the small aperture stop cap from the front of the cover. This is useful when observing very bright objects, like the full moon. The aper[...]

20 • The C150-HD The telescope should also be balanced on the declination axis to prevent any sudden motions when the DEC clamp is released. To balance the telescope in DEC: 1. Release the R.A. clamp and rotate the telescope so that it is on one side of the mount (i.e., as described in the previous section on balancing the telescope in R.A.). 2. [...]

The G-8N • 2 1 For the purpose of polar alignment, there are two directions in which the mount can be adjusted; vertically, which is called altitude and horizontally, which is called azimuth. There are several ways to align on the celestial pole, many of which are discussed later in this manual. This section simply covers the correct movement of [...]

22 • The C150-HD The entire telescope and mount is light enough to pick up and carry outside for a casual observing session. If, however, you want to transport your telescope to a remote observing location, you must partially disassemble it. Here ’ s how: 1. Remove the telescope from the equatorial mount. Return it to the shipping carton to ens[...]

The G-8N • 2 3 To install the finderscope onto the telescope you must first mount the finderscope through the finder bracket and then attach it to the telescope. Toward the front of the telescope tube, near the focusing assembly, there is a small bracket with a set screw in it. This is where the finderscope bracket will be mounted. To install the[...]

24 • The C150-HD The eyepiece, or ocular as it is also called, is an optical element that magnifies the image focused by the telescope. Without the eyepiece it would be impos- sible to use the telescope visually. The eyepiece fits directly into the eyepiece holder. To attach an ocular: 1. Loosen the set screw on the eyepiece holder so that it doe[...]

The G-8N • 2 5 Below is pertinent technical information on your G-8N and C150-HD telescope that you may find useful. G-8N C150-HD Optical System: Newtonian Reflector Newtonian Reflector Aperture: 200mm (8") 150mm (6") Focal Length: 1000mm (40") 750 mm (30") Highest Useful Power: 480x 360x Resolution (arc seconds): 0.58 .77 Lig[...]

26 • Telescope Basic TELESCOPE BASICS 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 will only affect your terrestrial observations. For celestial viewing, star charts can be[...]

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

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, this procedure should be done in the daytime when it is easy to find and identify objects. The finderscope has a spring-loaded adjustment screw that puts pressure on[...]

Telescope Basics • 29 With the telescope fully assembled and all the accessories attached you are ready for your first look. Your first look should be done in the daytime when it is easier to locate the locking clamps and slow motion adjustment knobs. This will help to familiarize you with your telescope, thus making it easier to use at night. Da[...]

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 eye and can be located by using landmarks. In addition, objects on the ground are stationary, or at least for the most part. In the night sky you will [...]

Telescope Basics • 31 As implied in the previous section, you can change the power of your Celestron telescope just by changing the eyepiece (ocular). To determine the magnification for your telescope, simply divide the focal length of the telescope (1000mm) by the focal length of the eyepiece you are using. In equation format, the formula looks [...]

32 • Astronomy Basics ASTRONOMY BASICS 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 coordinate system which is similar to our geographical coord[...]

Astronomy Basics • 33 Like the Sun, the stars also appear to move across the sky. This motion is caused by 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 around the south celestial pole. This means that[...]

34 • Astronomy Basics Figure 4-3 When the telescope’s axis of rotation is parallel to the Earth’s axis, stars viewed through 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 at the same rate as the stars. For the G-8N[...]

Astronomy Basics • 35 For each hemisphere, there is a point in the sky around which all the other stars appear to rotate. These points are called the celestial poles and are named for the hemisphere in which they reside. For example, in the northern hemisphere all stars move around the north celestial pole. When the telescope ’ s polar axis is [...]

36 • Astronomy Basics Latitude Scales The easiest way to polar align a telescope is with a latitude scale. Unlike other methods that require you to find the celestial pole by identifying certain stars near it, this method works off of a known constant to determine how high the polar axis should be pointed. The latitude range varies depending upon[...]

Astronomy Basics • 37 Pointing at Polaris This method utilizes Polaris as a guidepost to the celestial pole. Since Polaris is less than a degree from the celestial pole, many amateurs simply point the polar axis of their telescope at Polaris. Although this is by no means a perfect alignment, it is close. To align using this method: Align the find[...]

38 • Astronomy Basics Declination Drift This method of polar alignment allows you to get the most accurate alignment on the celestial pole and is required if you want to do long exposure deep-sky astrophotography through the telescope. The declination drift method requires that you monitor the drift of selected guide stars. The drift of each guid[...]

Astronomy Basics • 39 Polar Alignment Finders There are two finders specifically designed for polar alignment that can be used with the CG-4 and CG-5 mounts. These finders can be purchased as optional accessories for the C150-HD and G-8N. The first finder, known as the 7x50 Polaris finder (#51614), is used as a regular finder. The second finder i[...]

40 • Celestial Observing CELESTIAL OBSERVING 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-sky objects. In the night sky, the Moon is a prime target for your first look because it is extremely bright and easy to find. Often, it is a temptation to loo[...]

Celestial Observing • 41 Observing Deep-Sky Objects Although overlooked by many amateur astronomers, solar observation is both rewarding and fun. However, because the Sun is so bright, special precautions must be taken (always use the proper solar filter) when observing our star so as not to damage your eyes or your telescope. WARNING: Never proj[...]

42 • Celestial Observing Using the Setting Circles Once the setting circles are aligned you can use them to find any object with known coordinates. 1 . Select an object to observe. Use a seasonal star chart or planisphere to make sure the object you chose is above the horizon. As you become more familiar with the night sky, this will no longer be[...]

Celestial Observing • 43 Star Hopping You can use your setting circles to find these objects (as described earlier in this manual) or try star hopping. Star hopping is done by using bright stars to guide you to an object. Here are directions for two popular objects. The Andromeda Galaxy, M31, is an easy first target. To find M31: 1 . Locate the c[...]

44 • Celestial Observing Star hopping may take some getting used to since you can see more stars through the finder than you can see with the naked eye. And, some objects are not visible in the finder. One such object is M57, the famed Ring Nebula. Here ’ s how to find it: 1 . Find the constellation of Lyra, a small parallelogram visible in the[...]

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

46 • Celestial Observing temperature, don ’ t touch the telescope tube with your hands. When pointing the telescope, hold the telescope by the star diagonal. If observing with others, make sure no one stands in front of or directly below the telescope tube. The images produced by Type 2 seeing conditions don ’ t move as quickly as those produ[...]

Celestial Photography • 47 CELESTIAL PHOTOGRAPHY 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 are: short exposure prime focus, piggyback, eyepiece projection, [...]

48 • Celestial Photography Short exposure prime focus photography is the best way to begin recording celestial objects. It is done with the camera attached to the telescope without an eyepiece or camera lens in place. To attach your camera, you need the T-adapter and a T-Ring for your specific camera (i.e., Minolta, Nikon, Pentax, etc.). The C150[...]

Celestial Photography • 49 The exposure times listed here should be used as a starting point. Always make exposures that are longer and shorter than the recommended time. Also, try bracketing your exposures, taking a few photos at each shutter speed. This will ensure that you will get a good photo. If using black and white film, try a yellow filt[...]

50 • Celestial Photography 9. Close the camera ’ s shutter. As for lenses, use good ones that produce sharp images near the edge of the field. The lenses should have a resolving power of at least 40 lines per millime- ter. A good focal length range is 50 to 500mm for lenses designed for 35mm cameras. The exposure time depends on the film being [...]

Maintenance • 51 TELESCOPE MAINTENANCE After you have set up your telescope and started using it, there are a few things to remember for future reference. To minimize the need to clean your telescope, replace all lens covers once you have finished using it. Since the front of the telescope tube is open ALWAYS replace the front cover when the tele[...]

52 • Maintenance Prior to collimating the primary mirror holder, locate the three (3) screws on the end plate at the end of the tube. Unthread the three screws and remove the plate from the end of the tube. Under the end plate there are three (3) sets of two (2) screws. The shorter Allen screws push the mirror holder which is held by the longer o[...]

Optional Accessories • 53 OPTIONAL ACCESSORIES The following is a partial list of optional accessories available for your Celestron C150-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 magnification of that eyepiece. Celestron offers two Barlow lens[...]

54 • Optional Accessories • Lanthanum Eyepieces (LV Series) - Lanthanum is a unique rare earth glass used in one of the field lenses of this new eyepiece. The Lantha- num glass reduces aberrations to a minimum. All are fully multicoated and have an astounding 20mm of eye relief — perfect for eyeglass wearers! They are available in the followi[...]

Optional Accessories • 55 Single Axis Motor Drive System - #93518 By adding the MDCG-5 Drive System to your mount, you add the capacity to automatically track objects in the sky, a convenience you ’ ll be sure to enjoy during long viewing or astrophotography sessions, when manual tracking can become tiring. Furthermore, the Drive System will en[...]

56 • The Messier Catalog THE MESSIER CATALOG THE MESSIER CATALOG THE MESSIER CATALOG THE MESSIER CATALOG THE MESSIER CATALOG The Messier Catalog, compiled by Charles Messier, was the first extensive listing of star clusters and nebulae. Messier’s primary observational purpose was to discover comets. He compiled this list so that others searchin[...]

The Messier Catalog • 57 M # M # M # M # M # NGC# NGC# NGC# NGC# NGC# Const. Const. Const. Const. Const. R.A. R.A. R.A. R.A. R.A. DEC DEC DEC DEC DEC Mag Mag Mag Mag Mag Type Type Type Type Type Proper Name Proper Name Proper Name Proper Name Proper Name H M S H M S H M S H M S H M S ° ‘ ° ‘ ° ‘ ° ‘ ° ‘ M 3 6 NGC 1960 A u r 5 36.3 [...]

58 • The Messier Catalog M # M # M # M # M # NGC# NGC# NGC# NGC# NGC# Const. Const. Const. Const. Const. R.A. R.A. R.A. R.A. R.A. DEC DEC DEC DEC DEC Mag Mag Mag Mag Mag Type Type Type Type Type Proper Name Proper Name Proper Name Proper Name Proper Name H M S H M S H M S H M S H M S ° ‘ ° ‘ ° ‘ ° ‘ ° ‘ M 8 1 NGC 3031 U M a 9 55.8 [...]

List of Bright Stars • 59 LIST OF BRIGHT STARS LIST OF BRIGHT STARS LIST OF BRIGHT STARS LIST OF BRIGHT STARS LIST OF BRIGHT STARS The following is a list of bright stars that can be used to align the R.A. setting circle. All coordinates are in epoch 2000.0. Epoch 2000.0 Epoch 2000.0 Epoch 2000.0 Epoch 2000.0 Epoch 2000.0 Star Name Star Name Star[...]

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

CELESTRON ONE YEAR WARRANTY A. Cel estron w arrants this tele scope to be free from defects in materials and wor kmanship fo r one ye ar. Cele stron w ill repai r or repl ace such pro duct or part the reof w hich, upon inspe ction by Ce lestr on, is found to be defe ctive in material s or wo rkmanship . As a condition to the obligatio n of Cel estr[...]

2835 Columbia Street Torrance, CA 90503 Tel. (310) 328-9560 Fax (310) 212-5835 www.celestron.com Copyright 200 2 Celestron All rights reserved. (Products or instructions may change without notice or obligation.) Item # 31058-INST 0 8 -0 2 Price $10.00[...]