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Table of Contents
Related Manuals for Celestron 31058
Summary of Contents for Celestron 31058
- Page 1 C150-HD AND G-8N NEWTONIAN INSTRUCTION MANUAL Models #31056 and #31058...
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Page 3: Table Of Contents
Storing Your Telescope ... 22 Installing the Finderscope ... 23 Installing the Eyepiece ... 24 Technical Specifications ... 25 L L L L L TELESCOPE BASICS ... 26 Image Orientation ... 26 Focusing ... 27 Aligning the Finder ... 28 Your First Look ... - Page 4 L L L L L CELESTIAL PHOTOGRAPHY ... 47 Short Exposure Prime Focus ... 48 Piggyback ... 49 L L L L L TELESCOPE MAINTENANCE ... 51 Care and Cleaning of the Optics ... 51 Collimation ... 51 L L L L L OPTIONAL ACCESSORIES ... 53 L L L L L THE MESSIER CATALOG ...
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Page 5: L L L L L Introduction
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 the light gathering power of the unaided human eye. -
Page 6: How To Use This Manual
• 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. -
Page 7: The Newtonian Optical System
(some- times called an elliptical flat) and directed out of the telescope tube at a 90° angle to the incoming light rays (see figure 1-1). It is here that the eyepiece is placed to view the image formed by the telescope. -
Page 8: L L L L L Assembling Your Newtonian
• CG-4 German Equatorial Mount (Model #31056) • CG-5 German Equatorial Mount (Model #31058) • Counterweight Bar • Counterweight (5 kg for Model #31058 - 3.6kg and 1.8kg for Model #31056) • Declination (DEC) Slow Motion Knob • Right Ascension (R.A.) Slow Motion Knob •... - Page 9 The G-8N G-8N with CG-5 Equatorial Mount 1. Finderscope 2. Finderscope Bracket 3. Tube Ring 4. Piggyback Adapter 5. Latitude Scale 6. Latitude Adjustment Screw 7. Tripod 8. Accessory Tray Figure 2-1 9. Tripod Leg Clamp 10. Leg Brace Assembly 11.
- Page 10 The C150-HD 1. FinderscopeBracket 2. Finderscope 3. Tube Ring 4. Primary Mirror (inside tube) 5. Solw Motion Cables 6. Latitude Scale 7. Latitude Adjustment Screw 8. Tripod • The C150-HD Figure 2-1A C150-HD with CG-4 Equatorial Mount 9. Accessory Tray 10.
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Page 11: Setting Up The Tripod
The tripod comes fully assembled with the metal plate, called the tripod head, that Setting Up the Tripod 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 extended (see figure 2-2). -
Page 12: Attaching The Accessory Tray
4. Thread the wing bolts into the holes in the accessory tray. 5. Tighten the wing bolts fully. With the accessory tray in place, the tripod will be much more stable making it easier to attach the mount and telescope. • The C150-HD 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. -
Page 13: Attaching The Equatorial Mount
Attaching the Equatorial The equatorial mount allows you to tilt the telescope’s axis of rotation so that you Mount 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). -
Page 14: 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 (once it is attached to the mount). -
Page 15: Attaching The Declination Slow Motion Knob
DEC slow motion knob fits over is toward the top of the mount, just below the telescope mounting platform. Once again, you have two shafts to choose from. Use the shaft that is pointing toward the ground. This makes it easy to reach while looking through the telescope, something which is quite important when you are observing. -
Page 16: Installing The Counterweight Bar & Counterweights
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 lock nut by turning it counterclockwise. This 2. -
Page 17: Attaching The Telescope To The Mount
6 Hand tighten the mounting platform safety screw until the tip touches the side of the mounting bracket (see figure 2-5). Never loosen any of the knobs on the telescope tube or mount. Also, be sure NOTE: that the open end of the telescope is pointing away from the ground at all times. - Page 18 2. Locate the two holes on either end of the CG-4 mounting platform. 3. Hold the telescope up to the mount and slide the mounting rings until they are over 4. Place the flat portion of the ring over the mount so that the hole in the ring is over 5.
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Page 19: Balancing The Telescope In R.a
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. -
Page 20: Balancing The Telescope In Dec
DEC clamp is released. To balance the telescope in DEC: 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.). -
Page 21: Adjusting The Mount In Altitude
For fine adjustments in azimuth: Turn the azimuth adjustment screws located on either side of the azimuth housing at the base of the mount. While standing behind the telescope, the knobs are on the front of the mount. -
Page 22: Disassembling And Transporting Your G-8N
Storing Your Telescope When not in use, your Celestron telescope can be left fully assembled and set up. However, all lens and eyepiece covers should be put back in place. The opening to the focuser must also be covered. This will reduce the amount of dust build-up on the optical surfaces and reduce the number of times you need to clean the instru- ment. -
Page 23: Installing The Finderscope
To install the finderscope onto the telescope you must first mount the finderscope 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. -
Page 24: Installing The Eyepiece
In addition, eyepieces are also referred to by barrel diameter. The C150-HD and G- 8N use eyepieces with a barrel diameter of 1-1/4". Once the telescope is fully assembled, tighten the bolts that hold the tripod legs to the tripod head and the bolts that adjust the tripod height. Check these bolts periodically to ensure they are tight. -
Page 25: Technical Specifications
Technical Specifications Below is pertinent technical information on your G-8N and C150-HD telescope that you may find useful. Optical System: Aperture: Focal Length: Highest Useful Power: Resolution (arc seconds): Light Gathering Power: Limiting Visual Magnitude: Secondary Obstruction % of Primary Surface Area... -
Page 26: L L L L L Telescope Basics
Image Orientation only affect your terrestrial observations. For celestial viewing, star charts can be made to match the view in the telescope by rotating the chart 180° about the center. The view through the finder is also inverted. The figure illustrate the image orientation of a Newtonian telescope. Top is the actual orientation while below is the image seen through the telescope. -
Page 27: Focusing
This inconsistency can and will affect the ability to focus your telescope. In most cases you will not be able to achieve a truly sharp focus. In some cases, you may actually see a double image. -
Page 28: Aligning The Finder
Accurate alignment of the finder makes it easy to find objects with the telescope, Aligning the Finder 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. -
Page 29: 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. -
Page 30: Nighttime Observing
There is more on this in the section on “Polar Align- ment.” That’s all there is to using your Celestron Newtonian telescope. However, don’t limit your view of an object to a single eyepiece. After observing an object for a few minutes, try using a different optional eyepiece, perhaps a more powerful one. -
Page 31: Calculating Magnification (Power)
52.5. Continuing with our example, 1.04 times 52.5 produces a field size of 55 feet at 1,000 yards. The apparent field of each eyepiece that Celestron manufactures is found in the Celestron accessory catalog (#93685). Focal Length of Telescope (mm) Magnification = —————————————————... -
Page 32: L L L L L Astronomy Basics
Your Celestron telescope comes equipped with setting circles that translate the celestial coordinates into a precise location for the telescope to point. The setting circles will not work properly until you have polar aligned the telescope and set the R.A. -
Page 33: Motion Of The Stars
Like the Sun, the stars also appear to move across the sky. This motion is caused Motion of the Stars 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. -
Page 34: Polar Alignment
C150-HD there are also two optional motor drives (#93517 and #93522). The second thing you need is to set the telescope’s axis of rotation so that it tracks in the right direction. Since the motion of the stars across the sky is caused by the Earth’s rotation about its axis, the telescope’s axis must be made parallel to the Earth’s axis. -
Page 35: Finding The Pole
For example, in the northern hemisphere all stars move around the north celestial pole. When the telescope’s polar axis is pointed at the celestial pole, it is parallel to the Earth’s rotational axis. -
Page 36: Latitude Scales
If you are observing from Los Angeles, which has a latitude of 34°, then the celestial pole would be 34° above the northern horizon. All a latitude scale does then is to point the polar axis of the telescope at the right elevation above the northern (or southern) horizon. To align your telescope: 1. -
Page 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 finderscope with the main optical tube as described in the "Aligning... -
Page 38: Declination Drift
First choose your star near where the celestial equator and the meridian meet. The star should be approximately ±1/2 hour of the meridian and ±5 degrees of the celestial equator. Center the star in the field of your telescope and monitor the drift in declination. -
Page 39: Polar Axis Finder
2. Center the star in the finder. 3. Look through the main telescope and see if the star is in the field. If not, find it 4. Start the optional motor drive so that it will track the star. If you are not using 5. -
Page 40: L L L L L Celestial Observing
C E L E S T I A L 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. Observing the Moon In the night sky, the Moon is a prime target for your first look because it is extremely bright and easy to find. -
Page 41: Observing The Sun
Objects system. They include star clusters, planetary nebulae, diffuse nebulae, double stars, and other galaxies outside our own Milky Way. The Celestron Sky Maps (#93722) can help you locate the brightest deep-sky objects. Most deep-sky objects have a large angular size. Therefore, low-to-moderate power is all you need to see them. -
Page 42: Using The Setting Circles
3. Move the telescope in declination until the indicator is pointing at the 4. Move the telescope in R.A. until the indicator points to the correct coordi- 5. Look through the finder to see if you have located the object. -
Page 43: Star Hopping
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. - Page 44 5. Move about 1/2° toward Beta ( ) Lyrae, but remaining on a line that 6. Look through the telescope and the Ring Nebula should be in the tele- These two examples should give you an idea of how to star hop to deep sky objects.
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Page 45: Viewing Conditions
Extended objects, like the Moon, appear to shimmer while point sources (i.e., stars) appear double. Type 1 seeing is caused by currents within or very close to the telescope tube. These currents could be caused by a telescope that has not reached thermal equilibrium with the outdoor surroundings, heat waves from people standing near the telescope, or heated dew caps. - Page 46 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 produced by Type 1 conditions, but the images are quite blurry.
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Page 47: L L L L L Celestial Photography
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 are: short exposure prime focus, piggyback, eyepiece projection, and long exposure deep sky. -
Page 48: Short Exposure Prime Focus
Short exposure prime focus photography is the best way to begin recording celestial Short Exposure Prime objects. It is done with the camera attached to the telescope without an eyepiece or F o c u s 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.). -
Page 49: Piggyback
Because you are photographing with a low power lens and guiding with a high power telescope, the margin for error is very large. Small mistakes made while guiding the telescope will not show up on film. To attach the camera to the telescope, use the piggyback adapter screw located on the top of the tube mounting ring (see figure2-1). - Page 50 The longer the focal length, the more accurate your guiding must be. You can continue to increase the focal length of the lens until you are ready for prime focus photography with your Celestron telescope.
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Page 51: L L L L L Telescope Maintenance
Special care should be taken when cleaning any optical instrument so as not to damage the optics. Internal adjustments and cleaning should be done only by the Celestron repair department. If your telescope is in need of internal cleaning, please call the Celestron repair department for specific information on service. - Page 52 NOT needed unless the telescope has been dropped or damaged. If it requires an adjustment, contact your local astronomy club for more detailed instructions, consult a telescope users handbook, or call the Celestron technical support department.
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Page 53: L L L L L Optional Accessories
O P T I O N A L 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. - Page 54 • Lanthanum Eyepieces (LV Series) - Lanthanum is a unique rare earth Eyepiece Filters - To enhance your visual observations of solar system objects, Celestron offers a wide range of colored filters that thread into the 1-1/ 4" oculars. Available individually are: #12 deep yellow, #21 orange, #25 red, #58 green, #80A light blue, #96 neutral density - 25%T, #96 neutral density - 13%T, and polarizing.
- Page 55 The Celestron Planisphere makes it easy to locate stars for observing and is a great planet finder as well. A map of the night sky, oriented by month and day, rotates within a depiction of the 24 hours of the day, to display exactly which stars and planets will be visible at any given time.
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Page 56: L L L L L 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 searching for comets would not be confused by these objects. - Page 57 NGC# NGC# NGC# Const. Const. Const. NGC# NGC# Const. Const. NGC 1960 NGC 2099 NGC 1912 NGC 7092 NGC 2287 NGC 1976 NGC 1982 NGC 2632 NGC 2437 NGC 2422 NGC 2548 NGC 4472 NGC 2323 NGC 5194-5 NGC 7654 NGC 5024 NGC 6715 NGC 6809...
- Page 58 NGC# NGC# NGC# Const. Const. Const. NGC# NGC# Const. Const. NGC 3031 NGC 3034 NGC 5236 NGC 4374 NGC 4382 NGC 4406 NGC 4486 NGC 4501 NGC 4552 NGC 4569 NGC 4548 NGC 6341 NGC 2447 NGC 4736 NGC 3351 NGC 3368 NGC 3587 NGC 4192...
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Page 59: L L L L L List Of Bright Stars
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. -
Page 60: L L L L L For Further Reading
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 ... Pasachoff & Kutner Cambridge Atlas Of Astronomy ... Audouze & Israel McGraw-Hill Encyclopedia Of Astronomy ... - Page 61 Celestron, is found to be defective in materials or workmanship. As a condition to the obligation of Celestron to repair or replace such product, the product must be returned to Celestron together with proof-of-purchase satisfactory to Celestron.
- Page 62 2835 Columbia Street Torrance, CA 90503 Tel. (310) 328-9560 Fax (310) 212-5835 www.celestron.com Copyright 2002 Celestron All rights reserved. (Products or instructions may change without notice or obligation.) Item # 31058-INST 08-02 Price $10.00...