Page 4 - Warning
4 Congratulations on your purchase of the Celestron Advanced Series telescope (AST)! The Advanced Series of telescopes come in standard (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 ...
Page 5 - CONTROL PANEL; Hand Control Port
5 Fig 1-2 - The Advanced GT Series C80-GT Shown 1. Objective Lens 10. Focuser 2. Declination Motor Drive 11. Diagonal 3. RA /Dec locks 12. Eyepiece 4. Counterweight Bar 13. Finderscope 5. Counterweights CONTROL PANEL 6. Center Leg Brace / Accessory Tray A. Hand Control Port 7. 2" Steel Tripod B....
Page 6 - Tighten the levers on each leg clamp to hold the legs in place.
6 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. 21...
Page 7 - Locate the azimuth adjustment screws on the equatorial mount.; Do NOT remove the screws; Thread the accessory tray knob on to the central rod and tighten.; Mounting Knob
7 attaches to the tripod head. On one side of the tripod head there is a metal alignment peg for aligning the mount. This side of the tripod will face north when setting up for an astronomical observing session. To attach the equatorial head: 1. Locate the azimuth adjustment screws on the equatorial...
Page 9 - Never loosen any of the knobs on the
9 4. Slide the R.A. slow motion knob onto the R.A. shaft. The knob is a tension fit, so sliding it on holds it in place. As mentioned above, there are two R.A. shafts, one on either side of the mount. It makes no difference which shaft you use since both work the same. Use whichever one you find mor...
Page 10 - Installing the Finderscope; Loosen the set screw on the mounting bracket on the telescope.; Objective Lens
10 T T h h e e O O p p t t i i c c a a l l T T u u b b e e Installing the Finderscope 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, ...
Page 11 - Installing the Eyepieces; Loosen the set screw on the eyepiece adapter so that; GRADUALLY; — to see which way the telescope “rolls.”; Focuser Knob
11 Installing the Eyepieces 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 impossible to use the telescope visually. The eyepiece fits directly into the focuser. To attach an ocular: 1. Loosen th...
Page 12 - — to see which way it rotates around the declination axis.; DO NOT LET GO; Tighten the tube ring screws firmly to hold the telescope in place.
12 Balancing the Telescope in DEC The telescope should also be balanced on the declination axis to prevent any sudden motions when the DEC clamp (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...
Page 15 - Has a dual-line, 16 character display screen that is backlit for; The Advanced GT Hand Control
15 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...
Page 17 - Auto Align; Last Alignment; Enter; Mount Calibration
17 A A l l i i g g n n m m e e n n t t P P r r o o c c e e d d u u r r e e s s In order for the telescope to accurately point to objects in the sky, it must first be aligned to three known positions (stars) in the sky. With this information, the telescope can create a model of the sky, which it uses...
Page 18 - Pointing Accuracy
18 4. Select one of the four alignment methods as described below. Note: If incorrect information is entered into the hand control, the UNDO button acts like a back space button allowing the user to re-enter the correct data. A A u u t t o o A A l l i i g g n n Auto Align allows the telescope to aut...
Page 20 - Helpful
20 O O b b j j e e c c t t C C a a t t a a l l o o g g 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 ar...
Page 21 - Tour Mode; Filter Limits; Direction Buttons; Scope Setup
21 Tour Mode The Advanced Series telescopes include a tour feature which automatically allows the user to choose from a list of interesting objects based on the date and time in which you are observing. The automatic tour will display only those objects that are within your set filter limits (see Fi...
Page 22 - Tracking Mode; Used; Tracking Rate
22 1 = .5x 6 = 64x 2 = 1x (sidereal) 7 = .5º / sec 3 = 4x 8 = 2º / sec 4 = 8x 9 = 3º / sec 5 = 16x S S e e t t u u p p P P r r o o c c e e d d u u r r e e s s The Advanced GT contains many user defined setup functions designed to give the user control over the telescope's many advanced features. All...
Page 24 - Precise GoTo; Precise Goto; Scope Setup Features
24 Note: Some of the databases contain thousands of objects, and can therefore take several minutes to return the closest objects. Precise GoTo The Advanced Series telescopes have a precise goto function that can assist in finding extremely faint objects and centering objects closer to the center of...
Page 25 - figure shows the full range of motion
25 example, if you are observing from a mountainous location where the horizon is partially obscured, you can set your minimum altitude limit to read +20º. This will make sure that the hand control only displays objects that are higher in altitude than 20º. If you want to explore the entire object d...
Page 26 - CALIBRATE GOTO; UTILITIES
26 in R.A. (azimuth) until it reaches the point that the cables are extended to their maximum. Then by displaying the telescopes azimuth in this position (by looking at Get Alt-Az under the Utilities menu) you can determine the telescopes azimuth at its most extended position. Enter this azimuth rea...
Page 27 - Factory Settings; Version; Select Hibernate from the Utility Menu.
27 should be. Use the equatorial head latitude and azimuth adjustments to place Polaris in the center of the eyepiece. Do not use the direction buttons to position Polaris. Once Polaris is centered in the eyepiece press ENTER; the polar axis should then be pointed towards the North Celestial Pole. L...
Page 28 - MENU; ADVANCED GT
28 EQ NORTHEQ SOUTHOFF MODE SIDEREALSOLARLUNAR RAT E TRACKING VIEW TIME-SITE SETUP TIME-SITEANTI-BACKLASHFILTER LIMITSDIRECTION BUTTONSGOTO APPROACHAUTOGUIDE RATEAZIMUTH LIMITSEAST/WEST FILTERING SCOPE SETUP CALIBRATE GOTOHOME POSITIONPOLAR ALIGNLIGHT CONTROLFACTORY SETTINGVERSIONGET ALT-AZGOTO ALT-...
Page 31 - magnifica; Determining Field of View; a linear field width of 87.7; General Observing Hints
31 magnifica tion, most observing is done in the range of 20 to 35 power for every inch of aperture which for the 80ED is 64 to 112. Determining Field of View Determining the field of view is important if you want to get an idea of the angular size of the object you are observing. To calculate the a...
Page 32 - The Celestial Coordinate System; The celestial sphere seen from the outside showing R.A. and DEC
32 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 ...
Page 33 - Motion of the Stars
33 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 ...
Page 34 - Latitude Scales; NOT; Pointing at Polaris
34 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 Advance...
Page 35 - Finding the North Celestial Pole; Definition
35 Remember, while Polar aligning, do NOT move the telescope in R.A. or DEC. You do not want to move the telescope itself, but the polar axis. The telescope is used simply to see where the polar axis is pointing. Like the previous method, this gets you close to the pole but not directly on it. The f...
Page 37 - Observing the Moon; Lunar Observing Hints; Planetary Observing Hints; Observing the Sun
37 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. Observing the Moon Often, it is tempting to look at the Moon ...
Page 39 - Figure
39 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 seei...
Page 41 - Short Exposure Prime Focus Photography; Remove the eyepiece from the 1
41 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 l...
Page 42 - Advance the film and repeat the process.; Lunar Phase; Terrestrial Photography; telescope makes an excellent; Metering
42 6. Advance the film and repeat the process. Lunar Phase ISO 50 ISO 100 ISO 200 ISO 400 Crescent 1/2 1/4 1/8 1/15 Quarter 1/15 1/30 1/60 1/125 Full 1/30 1/60 1/125 1/250 The exposure times listed in table 7-1 should be used as a starting point. Always make exposures that are longer and shorter tha...
Page 43 - Auto Guiding
43 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 ...
Page 44 - Do NOT rub in circles!
44 While your telescope requires little maintenance, there are a few things to remember that will ensure your telescope performs at its best. C C a a r r e e a a n n d d C C l l e e a a n n i i n n g g o o f f t t h h e e O O p p t t i i c c s s Occasionally, dust and/or moisture may build up on the...
Page 45 - OMNI Plössl; Ultima; Axiom; Filters Sets
45 You will find that additional accessories enhance your viewing pleasure and expand the usefulness of your telescope. For ease of reference, all the accessories are listed in alphabetical order. Auxiliary Port Accessory (#93965) – This accessory plugs into the auxiliary port of the telescopes cont...
Page 47 - Appendix A – Technical Specifications; Advanced Series; Technical Specs
47 Appendix A – Technical Specifications Advanced Series 21021 / 21022 21026 / 21027 Specifications: Optical Design 80mm (3.2") refractor 100mm (4") refractor Focal Length 600mm F/7.5 900mm F/9 Finderscope 6x30 9x50 Mount CG-5 Equatorial CG-5 Equatorial Eyepiece 20mm – 1.25" (30x) 20mm –...
Page 48 - Appendix B - Glossary of Terms
48 Appendix B - Glossary of Terms A - Absolute magnitude The apparent magnitude that a star would have if it were observed from a standard distance of 10 parsecs, or 32.6 light-years. The absolute magnitude of the Sun is 4.8. at a distance of 10 parsecs, it would just be visible on Earth on a clear ...
Page 56 - Communication Protocol:; Description; Notes
56 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. Communication Protocol: The Ad...
Page 57 - Additional RS232 Commands
57 Additional RS232 Commands S S e e n n d d A A n n y y T T r r a a c c k k R R a a t t e e T T h h r r o o u u g g h h R R S S 2 2 3 3 2 2 T T o o T T h h e e H H a a n n d d C C o o n n t t r r o o l l 1. Multiply the desired tracking rate (arcseconds/second) by 4. Example: if the desired trackra...
Page 58 - APPENDIX E – MAPS OF TIME ZONES
Page 66 - CELESTRON TWO YEAR WARRANTY
66 CELESTRON TWO YEAR WARRANTY A. Celestron warrants this telescope to be free from defects in materials and workmanship for two years. 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 condit...
