Celestron 80GTL - Manuals

8 T T h h e e E E y y e e p p i i e e c c e e The eyepiece, is the optical element that magnifies the image focused by the telescope. The eyepiece fits either directly into the focuser or into the diagonal. To install the eyepiece: 1. Loosen the thumbscrew on the diagonal so it does not obstruct the...

10 U U s s i i n n g g y y o o u u r r S S o o l l a a r r F F i i l l t t e e r r Solar observing is one of the most rewarding forms of celestial observations. Yet, because the Sun is so bright, special precautions must be taken to ensure your safety and protect your equipment. Therefore, read thes...

11 A A t t t t a a c c h h i i n n g g 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 The NexStar GT hand control has a phone jack type connector at the end of its cord. Plug the phone jack connector into the outlet at the base of the telescope’s fork arm. Push the connector into the outlet...

12 Planets - All 8 planets in our Solar System plus the Moon. Stars – A compiled list of the brightest stars from the SAO catalog. List – For quick access, all of the best and most popular objects in the NexStar database have been broken down into lists based on their type and/or common name: Named ...

13 10. Scroll Keys: Used to scroll up and down within any of the menu lists. A double arrow symbol on the right side of the LCD indicates that the scroll keys can be used to view additional information. 11. Rate: Instantly changes the rate of speed of the motors when the direction buttons are presse...

14 Y Use the Up and Down scroll keys to choose between City Database and Custom Site . City Database will allow you to select the closest city to your observing site from a list of either international or U.S. location. Custom Site allows you to enter the exact longitude and latitude of your observi...

15 1. Once the NexStar is powered on, use the Up and Down scroll keys to select Two Two Two Two- - - -Star Align Star Align Star Align Star Align , and press ENTER. 2. The NexStar display will ask you to move the telescope tube until it is horizontal to the ground. To do this, use the direction keys...

16 Object Catalog S S e e l l e e c c t t i i n n g g a a n n O O b b j j e e c c t t Now that the telescope is properly aligned, you can choose an object from any of the catalogs in the NexStar's database. The hand control has a key designated for each of the catalogs in its database. There are two...

17 • To slew to the object displayed, press ENTER. • To see the next tour object, press the Down key. Direction Buttons The NexStar has four direction buttons in the center of the hand control which controls the telescope motion in altitude (up anddown) and azimuth (left and right). The telescope ca...

18 Alt-Az This is the default tracking rate and is used when the telescope has been properly aligned. EQ North Used to track the sky when the telescope is polar aligned using an equatorial wedge in the Northern Hemisphere. EQ South Used to track the sky when the telescope is polar aligned using an e...

19 objects are relative to the location of the telescope, they are only valid for that exact location. To save land objects, once again center the desired object in the eyepiece. Scroll down to the " Save Land Obj " command and press ENTER. The display will ask you to enter a number between ...

20 Slew Limits – Sets the limits in altitude that the telescope can slew without displaying a warning message first. The NexStar hand control will warn you before allowing the telescope tube to slew to an object below the horizon or slew to an object that is high enough that the tube might hit one o...

22 Correct image as viewed when using erect image diagonal Inverted image, as viewed with the eyepiece directly in telescope A telescope is an instrument that collects and focuses light. The nature of the optical design determines how the light is focused. Some telescopes, known as refractors, use l...

25 •Sunspots : Dark regions of the sun's photosphere which are cooler than the surrounding area. Sunspots are usually seen to consist of two parts: the inner darker core, the umbra, and the surrounding less dark region, the penumbra. •Granulation : Small convection cells in the photosphere that appe...

27 While your NexStar telescope requires little maintenance, there are a few things to remember that will ensure your telescope performs at its best. Care and Cleaning of the Optics Occasionally, dust and/or moisture may build up on the lens of your telescope. Special care should be taken when clean...

30 APPENDIX A - TECHNICAL SPECIFICATIONS O O O p p p t t t i i i c c c a a a l l l S S S p p p e e e c c c i i i f f f i i i c c c a a a t t t i i i o o o n n n NexStar 80GTL Design Refractor Aperture 80mm Focal Length 900mm F/ratio of the Optical System F/11 Objective Coatings Fully Coated Highest ...

31 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 moonless nigh...

34 Appendix C - RS-232 Connection You can control your NexStar telescope with a computer via the PC port on the hand control and using an optional RS-232 cable (see Optional Accessories section of manual). Once connected, the NexStar can be controlled using popular astronomy software programs. C C o...

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 condition...