Installing the Counterweight ... 8 Attaching the Hand Control Holder... 8 Attaching the Slow Motion Knobs ... 8 Attaching the Telescope Tube to the Mount... 9 The Optical Tube... 10 Balancing the Tube in R.A..11 Adjusting the Mount... 12 Adjusting the Mount in Altitude ...
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Version ... 27 Get Alt-Az ... 27 Goto Alt-Az ... 27 Hibernate ... 27 Turn On/Off GPS ... 27 TELESCOPE BASICS ... 29 Image Orientation ... 29 Focusing ... 30 Aligning the Finderscope ... 30 Calculating Magnification ... 30 Determining Field of View ... 31 General Observing Hints...
(non-computerized) and computerized GT models. The Advanced Series is made of the highest quality materials to ensure stability and durability. All this adds up to a telescope that gives you a lifetime of pleasure with a minimal amount of maintenance.
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Fig 1-2 - The Advanced GT Series Objective Lens Declination Motor Drive RA /Dec locks Counterweight Bar Counterweights Center Leg Brace / Accessory Tray 2" Steel Tripod Hand Control R.A. Motor Drive / Control Panel C80-GT Shown Focuser Diagonal Eyepiece Finderscope CONTROL PANEL Hand Control Port...
This section covers the assembly instructions for your Celestron Advanced Series Telescope (AST). Your AST telescope should be set up indoor the first time so that it is easy to identify the various parts and familiarize yourself with the correct assembly procedure before attempting it outdoor.
Once the bar is securely in place you are ready to attach the counterweight. Since the fully assembled telescope can be quite heavy, position the mount so that the polar axis is pointing towards north before the tube assembly and counterweights are attached. This will make the polar alignment procedure much easier.
6. Replace the counterweight safety screw. The Advanced GT telescope models come with a hand control holder to place the computerized hand control. The hand control holder comes in two pieces: the leg clamp that snaps around the tripod leg and the holder which attaches to the leg clamp.
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 mount, just below the telescope mounting platform. Once again, you have two shafts to choose from.
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 rear 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 finderscope: Slide the rubber O-ring over the eyepiece end of the finderscope and roll it 2/3 of the way up the finderscope.
To balance the mount: 1. Release the R.A. Clamp (see figure 2-15) and position the telescope off to one side of the mount (make sure that the mounting bracket screw is tight).
(Fig 2-5) 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.).
Now, using only the rear screw, raise the mount to your desired latitude. Adjusting the Mount in Azimuth For rough adjustments in azimuth, simply pick up the telescope and tripod and move it. For fine adjustments in azimuth: 1. Turn the azimuth adjustment knobs located on either side of the azimuth housing (see Fig 2-14). While standing behind the telescope, the knobs are on the front of the mount.
The Advanced GT can be powered by the supplied car battery adapter or optional 12v AC adapter. Use only adapters supplied by Celestron. Using any other adapter may damage the electronics or cause the telescope not to operate properly, and will void your manufacturer's warranty.
The Advanced Series GT, computerized version of each telescope has a hand controller designed to give you instant access to all the functions that your telescope has to offer. With automatic slewing to over 40,000 objects, and common sense menu descriptions, even a beginner can master its variety of features in just a few observing sessions.
Alignment, Setup and Utilities. The alignment section deals with the initial telescope alignment as well as finding objects in the sky; the setup section discusses changing parameters such as tracking mode and tracking rate; finally, the last section reviews all of the utilities functions such as calibrating your mount, polar alignment and backlash compensation.
Auto Three Star Align involves the same process as Auto Align, however it allows the user to select which star to use to align the telescope. Quick-Align will ask you to input all the same information as you would for the Auto Align procedure.
Meridian and have you repeat this procedure for that star. 5. For the third alignment star, the telescope will select a bright star on the opposite side of the Meridian and slew to it. Once again center the star in the crosshairs of the finderscope and then center the star in the eyepiece, pressing ENTER when complete.
This will allow you to roughly slew to the coordinates of bright objects like the moon and planets and gives the telescope the information needed to track objects in any part of the sky (depending on accuracy of polar alignment).
Selecting an Object Now that the telescope is properly aligned, you can choose an object from any of the catalogs in the telescope's extensive database. The hand control has a key (4) designated for each of the catalogs in its database. There are two ways to select objects from the database: scrolling through the named object lists and entering object numbers.
Constellation Tour In addition to the Tour Mode, your telescope has a Constellation Tour that allows the user to take a tour of all the best objects in each of the 88 constellations. Selecting Constellation from the LIST menu will display all the constellation names that are above the user defined horizon (filter limits).
5 = 16x The Advanced GT contains many user defined setup functions designed to give the user control over the telescope's many advanced features. All of the setup and utility features can be accessed by pressing the MENU key and...
Additionally, Identify Mode can be used to find other celestial objects that are close to the objects you are currently observing. For example, if your telescope is pointed at the brightest star in the constellation Lyra, choosing Identify and then searching the Named Star catalog will no doubt return the star Vega as the star you are observing.
(west) for azimuth and counterclockwise in declination. Declination Goto approach will only apply while the telescope tube is on one side of the Meridian. Once the tube passes over to the other side of the Meridian, the Goto approach will need to be reversed.
Warning: In order for the telescope to be able to slew to a star from the direction that minimizes the amount of backlash in the gears, it may be necessary for the telescope to slew beyond the specified slew limit in order to approach the star from the correct direction.
Accessories section of the manual), you will need to turn the GPS on the first time you use the accessory. . If you want to use the telescope's database to find the coordinates of a celestial object for a future or past dates you would...
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ADVANCED GT MENU ALIGNMENT TRACKING START-UP PROCUDURE MODE EQ NORTH EQ SOUTH RATE SIDEREAL SOLAR LUNAR VIEW TIME-SITE SCOPE SETUP SETUP TIME-SITE ANTI-BACKLASH FILTER LIMITS DIRECTION BUTTONS GOTO APPROACH AUTOGUIDE RATE AZIMUTH LIMITS EAST/WEST FILTERING UTILITIES CALIBRATE GOTO HOME POSITION POLAR ALIGN LIGHT CONTROL FACTORY SETTING...
Some telescopes, known as refractors, use lenses. Other telescopes, known as reflectors, use mirrors. Developed in the early 1600s, the refractor is the oldest telescope design. It derives its name from the method it uses to focus incoming light rays. The refractor uses a lens to bend or refract incoming light rays, hence the name (see Figure 4-1).
Although the power is variable, each instrument has a limit to the highest useful magnification. The general rule is that 60 power can be used for every inch of aperture. For example, in a 3.2” diameter telescope, such as the 80ED, the maximum useful magnification is 192 power.
To convert degrees to feet at 1,000 yards, which is more useful for terrestrial observing, simply multiply by 52.5. Continuing , multiply the angular field 1.67 with our example one thousand yards. The apparent field of each eyepiece that Celestron manufactures is found in the Celestron Accessory Catalog (#93685). General Observing Hints When working with any optical instrument, there are a few things to remember to ensure you get the best possible image.
Up to this point, this manual covered the assembly and basic operation of your telescope. However, to understand your telescope more thoroughly, you need to know a little about the night sky. This section deals with observational astronomy in general and includes information on the night sky and polar alignment.
Motion of the Stars The daily motion of the Sun across the sky is familiar to even the most casual observer. This daily trek is not the Sun moving as early astronomers thought, but the result of the Earth's rotation. The Earth's rotation also causes the stars to do the same, scribing out a large circle as the Earth completes one rotation.
If you are observing from Los Angeles, which has a latitude of 34°, then the celestial pole is 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.
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.
So, repeat the process again to improve the accuracy checking both axes for minimal drift. Once the drift has been eliminated, the telescope is very accurately aligned. You can now do prime focus deep-sky astrophotography for long periods.
With your telescope set up, you are ready to use it for observing. This section covers visual observing hints for both solar system and deep sky objects as well as general observing conditions which will affect your ability to observe.
The best time to observe the Sun is in the early morning or late afternoon when the air is cooler. • To center the Sun without looking into the eyepiece, watch the shadow of the telescope tube until it forms a circular shadow.
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disturbances vary from time-to-time and place-to-place. The size of the air parcels compared to your aperture determines the "seeing" quality. Under good seeing conditions, fine detail is visible on the brighter planets like Jupiter and Mars, and stars are pinpoint images. Under poor seeing conditions, images are blurred and stars appear as blobs. The conditions described here apply to both visual and photographic observations.
The camera must have interchangeable lenses so you can attach it to the telescope and so you can use a variety of lenses for piggyback photography. If you can't find a new camera, you can purchase a used camera body that is not 100-percent functional.
5. Locate the area of the sky that you want to photograph and move the telescope so that it points in that direction. 6. Find a suitable guide star in the telescope eyepiece field of view. This is relatively easy since you can search a wide area without affecting the area covered by your camera lens.
Your done will the telescope tracking drive turned off. To turn the tracking drive off, press the MENU (9) button on the hand control and scroll down to the Tracking Mode sub menu. Use the Up and Down scroll keys (10) to select the Off option and press ENTER.
Auto Guiding The Advanced GT telescope has a designated auto guiding port for use with a CCD autoguider. The diagram below may be useful when connecting the CCD camera cable to the telescope and calibrating the autoguider. Note that the four outputs are active-low, with internal pull-ups and are capable of sinking 25...
NOT sealed, the cover should be placed over the opening when not in use. This will prevent contaminants from entering the optical tube. 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 factory for a return authorization number and price quote.
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 in the 1-1/4" size. The 2x Ultima Barlow (#93506) is a compact triplet design that is fully multicoated for maximum light transmission and parfocal when used with the Ultima eyepieces.
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Sky Map (#93722) - Celestron Sky Maps are the ideal teaching guide for learning the night sky. You wouldn’t set off on a road trip without a road map, and you don’t need to try to navigate the night sky without a map either.
Resolution: Rayleigh Dawes Limit Light Gathering Power Field of View: standard eyepiece Linear FOV (@1000 yds) Optical Coatings - Standard Optical tube length Telescope Weight Advanced GT Additional Specifications Hand Control Motor: Type Max Slew Speed Software Precision Hand Control Ports...
Sun against the stars". Equatorial mount A telescope mounting in which the instrument is set upon an axis which is parallel to the axis of the Earth; the angle of the axis must be equal to the observer's latitude.
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1 and those increasingly fainter from 2 down to magnitude 5. The faintest star that can be seen without a telescope is about magnitude 6. Each magnitude step corresponds to a ratio of 2.5 in brightness. Thus a star of magnitude 1 is 2.5 times brighter than a star of magnitude 2, and 100 times brighter than a magnitude 5 star.
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The rate is 15 arc seconds per second or 15 degrees per hour. Terminator boundary Universe The totality of astronomical things, events, relations and energies capable of being described objectively. Variable Star A star whose brightness varies over time due to either inherent properties of the star or something eclipsing or obscuring the brightness of the star.
Appendix D - RS-232 Connection You can control your telescope with a computer via the RS-232 port on the computerized hand control and using an optional RS-232 cable (#93920). Once connected, the telescope can be controlled using popular astronomy software programs.
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Additional RS232 Commands 1. Multiply the desired tracking rate (arcseconds/second) by 4. Example: if the desired trackrate is 150 arcseconds/second, then TRACKRATE = 600 2. Separate TRACKRATE into two bytes, such that (TRACKRATE = TrackRateHigh*256 + rackRateLow). Example: TrackRateHigh = 2 TrackRateLow = 88 3.
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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.
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Celestron 2835 Columbia Street Torrance, CA 90503 U.S.A. Tel. (310) 328-9560 Fax. (310) 212-5835 Web site at http//www.celestron.com Copyright 2003 Celestron All rights reserved. (Products or instructions may change without notice or obligation.) Item # 21021-INST Printed in China $10.00...