INSTRUCTION MANUAL
INTRODUCTION ........................................................................................................................................ 4 WARNING .................................................................................................................................................... 4 QUICK SETUP ............................................................................................................................................. 5 ASSEMBLY ....................................
POLAR ALIGNMENT (WITH OPTIONAL WEDGE) ......................................................................................... 29 Photography with the NexStar 4 .......................................................................................................... 30 Finding the North Celestial Pole ......................................................................................................... 31 CELESTIAL OBSERVING...............................................................................
Congratulations on your purchase of the Celestron NexStar! The NexStar ushers in a whole new generation of computer automated technology. Simple and friendly to use, the NexStar is up and running after locating just two alignment stars. It’s the perfect combination of power and portability. If you are new to astronomy, you may wish to start off by using the NexStar's built-in Sky Tour feature, which commands the NexStar to find the most interesting objects in the sky and automatically slews to each one.
3 Eyepiece StarPointer 1 Flip Mirror Focuser Knob Attach the included accessories (eyepiece and Star Pointer finderscope) and remove the front lens cover. Turn-on the Star Pointer by rotating the dial on the side. (For instructions on aligning the Star Pointer see the Assembly section of the manual). Remove the NexStar from its packaging and place the base on a sturdy, level surface. Remove the accessories from their individual boxes.
5 7 Direction Buttons Up and Down Scroll Buttons Catalog Keys Object List Button Input the necessary date and time information as instructed by the hand control. Press ENTER after each entry. The NexStar will also ask for time zone and location information. Use the UP and Down scroll buttons to select from the various options, pressing ENTER after each selection. (See Hand Control section for detailed alignment procedures). TOUR Button Press the TOUR button on the hand control.
9 1 10 8 2 7 3 6 5 4 1 2 Optical Tube Liquid Crystal Display 6 7 Focuser Knob Straight Through Photographic Adapter 3 Hand Control 8 Flip Mirror Control 4 ON/OFF Switch 9 Eyepiece 5 Battery Compartment 10 Star Pointer Finderscope 7
The NexStar 4 comes completely pre-assembled and can be operational in a matter of minutes. The NexStar is conveniently packaged in one reusable shipping carton that contains all of the following accessories: • • • 25mm SMA Eyepiece – 1¼" Star Pointer Finderscope and Mounting Bracket The Sky® for Celestron Astronomy Software Assembling the NexStar Start by removing the telescope from its shipping carton and setting the round base on a flat table or surface.
The Hand Control The hand control is located on the side of the fork arm and can be removed and used remotely or used while attached to the fork. The hand control attaches to the fork arm by resting on two posts, located on the bottom of the hand control cradle, and a clip inside the fork arm. To remove the hand control from the fork arm cradle, gently lift the hand control upwards and pull out.
The Star Pointer Finderscope The Star Pointer is the quickest and easiest way to point your telescope exactly at a desired object in the sky. It's like having a laser pointer that you can shine directly onto the night sky. The Star Pointer is a zero magnification pointing tool that uses a coated glass window to superimpose the image of a small red dot onto the night sky.
3. With both eyes open, look through the glass window at the alignment star. 4. If the Star Pointer is perfectly aligned, you will see the red LED dot overlap the alignment star. If the Star Pointer is not aligned, take notice of where the red dot is relative to the bright star. 5. Without moving the main telescope, turn the Star Pointer's azimuth and altitude alignment controls until the red dot is directly over the alignment star.
The NexStar 4 HC telescope is a precision scientific instrument that will allow you to enjoy viewing numerous objects in the night sky — planets, nebulae, star clusters, galaxies and more. Equipped with high speed motors and hand control, the NexStar HC allows you to remotely move your telescope to desired objects quickly and accurately. At a touch of a button, you can slew your telescope across the sky in a matter of seconds and continuously track objects as the Earth rotates beneath them.
Star Key: Gives the user access to the utility functions of the hand control, such as changing the direction of the arrow keys and backlash compensation. Hand Control Slew Rate Indicator Lights: Displays the speed at which the telescope will move when each direction button is pressed. 4. 5. Rate Button Pressing the RATE key (3) allows you to instantly change the speed rate of the motors from high speed slew rate to precise centering rate or two speeds in between.
3. 4. Use the UP and Down arrow keys to speed up or slow down the initial speed of the altitude motors when the arrow buttons are pressed. Press the STAR key on the hand control again to activate the direction buttons again. GuideStar Software The NexStar HC has an RS-232 port on the back of the hand control, allowing it to be controlled using the GuideStar telescope control software. Linking the NexStar to a computer requires the use of a RS-232 cable.
The NexStar GT has a removable hand controller built into the side of the fork arm designed to give you instant access to all the functions the NexStar has to offer. With automatic slewing to over 4,000 objects, and common sense menu descriptions, even a beginner can master its variety of features in just a few observing sessions. Below is a brief description of the individual components of the NexStar GT hand controller: 1. 2. 3.
Messier – Complete list of all Messier objects. NGC – Complete list of all the deep-sky objects in the Revised New General Catalog. Caldwell – A combination of the best NGC and IC objects. Planets - All 8 planets in our Solar System plus the Sun and moon. Stars – A compiled list of the brightest stars from the SAO catalog.
with all accessories (eyepiece and Star Pointer) attached and lens cover removed as described in the Assembly section of the manual. 1. 2. 3. Once the NexStar is powered on , Press ENTER to begin alignment. Use the Up and Down scroll keys to select AutoAlign if it is not already displayed, and press ENTER. The telescope will then ask you to use the arrow keys (3) to level the telescope tube and point the front of the telescope towards north.
In order to accurately center the alignment star in the eyepiece, it may be necessary to decrease the slew rate of the motors for fine centering. This is done by pressing the RATE key (11) on the hand controller then selecting the number that corresponds to the speed you desire. (9 = fastest , 1 = slowest). Third Star Alignment The NexStar has a third star alignment feature which allows you to replace either of the two original alignment stars with a new star.
1. Press the INFO Key. This will give you useful information about the selected object such as R.A. and declination, magnitude and most importantly, altitude above the horizon. (If a star alignment has not yet been performed, the altitude will not be displayed). The speed at which information scrolls across the hand control display can be changed while the information is being viewed: Hold down the “1” key to speed up the scroll speed. • Hold down the “4” key to slow down the scroll speed.
The hand control has a "double button" feature that allows you to instantly speed up the motors without having to choose a speed rate. To use this feature, simply press the arrow button that corresponds to the direction that you want to move the telescope. While holding that button down, press the opposite directional button. This will increase the slew rate to approximately 1º per second (equal to rate 7 on the hand control).
Sidereal Lunar This rate compensates for the rotation of the earth by moving the telescope at the same rate as the rotation of the earth, but in the opposite direction. When the telescope is polar aligned, this can be accomplished by moving the telescope in Right Ascension only. When mounted in AltAz mode, the telescope must make corrections in both R.A. and declination. Used for tracking the moon when observing the lunar landscape.
Goto Alt-Az Helpful Hint - Allows you to enter a specific altitude and azimuth position and slew to it. To store a set of coordinates (R.A./Dec) permanently into the NexStar database, save it as a User Defined Object as described above. Utility Features Scrolling through the MENU options will also provide access to several advanced utility functions within the NexStar such as cord wrap and anti-backlash.
N exStar R ead y M ENU ALIG N M E N T T R A C K IN G M O D E ALT-AZ EQ NO RTH EQ SO UTH O FF LIS T NAM ED STARS NAM ED O BJECTS DO UBLE STARS VARIABLE STARS ASTERISM S TO UR PLANETS A U T O A L IG N NO RTH & LEVEL ENTER DATE T R A C K IN G R A T E ENTER TIM E SIDEREAL SO LAR LUNAR KING G E T A L T -A Z G E T R A -D E C G O T O A L T -A Z G O T O R A -D E C U S E R OB JE C T S SELECT M ETHO D CHO O SE CITY UNITED STATES Choose State G O TO SKY O BJECT G O TO LAND O BJECT SAVE SKY O BJECT SAVE LAN
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 lenses. Other telescopes, known as reflectors, use mirrors. The Maksutov-Cassegrain optical system uses a combination of mirrors and lenses and is referred to as a compound or catadioptric telescope. This unique design offers large-diameter optics while maintaining very short tube lengths, making them extremely portable.
Focusing The NexStar's focusing mechanism controls the primary mirror which is mounted on a ring that slides back and forth on the primary baffle tube. The focusing knob, which moves the primary mirror, is on the rear cell of the telescope just below the star diagonal and eyepiece. Turn the focusing knob until the image is sharp. If the knob will not turn, it has reached the end of its travel on the focusing mechanism. Turn the knob in the opposite direction until the image is sharp.
General Observing Hints When working with any optical instrument, there are a few things to remember to ensure you get the best possible image. • • • • Never look through window glass. Glass found in household windows is optically imperfect, and as a result, may vary in thickness from one part of a window to the next. This inconsistency can and will affect the ability to focus your telescope.
Up to this point, this manual covered the assembly and basic operation of your NexStar 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. The Celestial Coordinate System To help find objects in the sky, astronomers use a celestial coordinate system that is similar to our geographical coordinate system here on Earth.
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. The size of the circular path a star follows depends on where it is in the sky.
Polar Alignment (with optional Wedge) Even though the NexStar can precisely track a celestial object while in the Alt-Az position, it is still necessary to align the polar axis of the telescope (the fork arm) to the Earth's axis on rotation in order to attempt long exposure astro photography. To do an accurate polar alignment, the NexStar requires an optional equatorial wedge (#93658) between the telescope and a tripod. Celestron also offers a steel tripod with an attached wedge tilt plate (#93497).
3. Once complete the NexStar will automatically slew to the first alignment star. If the star that is chosen is in the north, it may be below the horizon. If so, abort the slew by pressing any of the arrow direction buttons before the telescope tube comes into contact with the base. Press the UNDO button to select an alignment star that is above the horizon. Use the hand control to center the alignment star with the Star Pointer and press ENTER, then center the star in the eyepiece and press ALIGN.
Finding the North Celestial Pole In 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 pointed at the celestial pole, it is parallel to the Earth's rotational axis.
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 when it is full. At this time, the face we see is fully illuminated and its light can be overpowering. In addition, little or no contrast can be seen during this phase.
Observing the Sun 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 when observing our star so as not to damage your eyes or your telescope. Never project an image of the Sun through the telescope. Because of the folded optical design, tremendous heat build-up will result inside the optical tube. This can damage the telescope and/or any accessories attached to the telescope.
Seeing Seeing conditions refers to the stability of the atmosphere and directly affects the amount of fine detail seen in extended objects. The air in our atmosphere acts as a lens which bends and distorts incoming light rays. The amount of bending depends on air density. Varying temperature layers have different densities and, therefore, bend light differently. Light rays from the same object arrive slightly displaced creating an imperfect or smeared image.
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 corrector plate of your telescope. Special care should be taken when cleaning any instrument so as not to damage the optics. If dust has built up on the corrector plate, remove it with a brush (made of camel’s hair) or a can of pressurized air.
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. Adapter, AC (#18770) – Allows DC (battery) powered telescopes to be converted for use with 120 volt AC power. The adapter attaches to any standard wall outlet. Adapter, Car Battery (#18769) - Celestron offers the Car Battery Adapter that allows you to run the NexStar drive off an external power source.
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. These and other filters are also sold in sets.
Tripod, NexStar - A stable tripod is a must for serious astronomical observing and photography. This steel field tripod (#93497) folds down to a compact 8"x28". It is equipped with a built on wedge tilt plate for quick equatorial use and astrophotography. It has a metal center brace and accessory tray for added stability. Vibration Suppression Pads (#93503) - These pads rest between the ground and tripod feet of your telescope.
Appendix A - Technical Specifications O Oppttiiccaall S Sppeecciiffiiccaattiioonn Design Aperture Focal Length F/ratio of the Optical System Primary Mirror: Diameter Coatings Secondary Mirror Spot Size Secondary Obstruction Corrector Plate: Material Coatings Highest Useful Magnification Lowest Useful Magnification (7mm exit pupil) Resolution: Rayleigh Criterion Dawes Limit Photographic Resolution Light Gathering Power Near Focus standard eyepiece or camera Field of View: Standard Eyepiece : 35mm Camera Line
Appendix B - Glossary of Terms AAbsolute magnitude Airy disk Alt-Azimuth Mounting Altitude Aperture Apparent Magnitude Arcminute Arcsecond Asterism Asteroid Astrology Astronomical unit (AU) Aurora Azimuth BBinary Stars CCelestial Equator Celestial pole Celestial Sphere Collimation DDeclination (DEC) EEcliptic Equatorial mount 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.
FFocal length JJovian Planets KKuiper Belt LLight-Year (ly) MMagnitude Meridian Messier NNebula North Celestial Pole Nova OOpen Cluster PParallax Parfocal Parsec Point Source RReflector The distance between a lens (or mirror) and the point at which the image of an object at infinity is brought to focus. The focal length divided by the aperture of the mirror or lens is termed the focal ratio.
Resolution Right Ascension: (RA) SSidereal Rate TTerminator UUniverse VVariable Star The minimum detectable angle an optical system can detect. Because of diffraction, there is a limit to the minimum angle, resolution. The larger the aperture, the better the resolution. The angular distance of a celestial object measured in hours, minutes, and seconds along the Celestial Equator eastward from the Vernal Equinox. This is the angular speed at which the Earth is rotating.
Appendix C – Maps of Time Zones 43
CELESTRON ONE YEAR WARRANTY A. Celestron International (CI) warrants this telescope to be free from defects in materials and workmanship for one year. CI will repair or replace such product or part thereof which, upon inspection by CI, is found to be defective in materials or workmanship. As a condition to the obligation of CI to repair or replace such product, the product must be returned to CI together with proof-of-purchase satisfactory to CI. B.
Celestron International 2835 Columbia Street Torrance, CA 90503 Tel. (310) 328-9560 Fax. (310) 212-5835 Web site at http//www.celestron.com Copyright 2000 Celestron International All rights reserved. (Products or instructions may change without notice or obligation.) This device complies with Part 15 of the FCC Rule.
ADDENDUM TO NEXSTAR 4 TELESCOPE MANUAL This document contains useful information about your NexStar 4 telescope that may not have been included in your instruction manual at the time of printing. Listed below is information regarding the utility features described under the hand control section of the manual. Please refer to this addendum when using your NexStar 4 hand control.
