Model #21072 F80 EQ WA 80mm (3.1") REFRACTOR TELESCOPE INSTRUCTION MANUAL Figure 1 Finderscope Tube Ring Knurled Screw (opposite of tube ring hinge) Finder Bracket Focusing Set Screw Square Extrusions Mounting Platform Figure 2 5 1. INTRODUCTION Thank you for purchasing this Celestron 80mm Refractor Equatorial Telescope. This telescope is a precision scientific instrument. With it you will enjoy numerous objects in the sky--planets, nebulae, star clusters, galaxies and other astronomical objects. But, before your journey begins take time to read this manual to familiarize yourself with the operation and parts of this telescope. WARNING--NEVER LOOK AT THE SUN WITH YOUR TELESCOPE OR ITS FINDERSCOPE. PERMANENT AND IRREVERSIBLE EYE DAMAGE MAY RESULT AS WELL AS DAMAGE TO YOUR TELESCOPE. HOWEVER, YOU MAY ENJOY LOOKING AT THE SUN IF YOU HAVE A SAFE METHOD OF DOING SO--A SOLAR FILTER. IF USING A SOLAR FILTER, MAKE SURE THE FINDERSCOPE IS COVERED. 2. TELESCOPE ASSEMBLY Please refer to figures 1 and 2 (and the identifying parts list) as you assemble the telescope. The telescope and all items are packed in one box. Included are: · Telescope Optical Tube · German Equatorial Mount · Adjustable Wood Tripod · Counterweight Shaft and Counterweight · Tripod Accessory Tray · Declination Cable · Right Ascension Cable · 25mm SMA Eyepiece - 1¼" (16x) · Diagonal - 1¼" · Finderscope, 6x30 A. Locate the German equatorial mount and the tripod legs along with the tripod mounting hardware and the tripod accessory tray. 1. Lie the tripod head (#7) on its side. Attach the three tripod legs (#12) one by one to the tripod head with the bolts and wing nuts (#17). Do not over tighten the bolts but just make them lightly finger tight. Remember to have each tripod leg in the right orientation with the tripod tray bracket (#11) facing inward. Next, put the bolts and wing nuts in the bottom of the tripod legs through the holes for the height adjustment you want. We suggest you keep it at the lowest height for assembly (you can raise it later if you wish) and for maximum rigidity. NOTE--this may have been assembled at the factory. Now set the tripod with the equatorial mount attached in the standing position by spreading the legs apart far enough for the tripod accessory tray (#11) to fit. You are now ready to install the tripod accessory tray (#11). The tripod tray bracket fits into slots in the bottom of the tray (use the holes on the ends of the brackets). Use the bolts and wing nuts to attach each bracket to the tray. 2. 3. 4. 6 5. Tighten all bolts and wing nuts to ensure proper stability. B. Before proceeding further, locate knobs #19 and #16 and tighten them finger tight after orienting the mount as illustrated in figure 1. 1. Locate the declination cable holder (where #21 fits on). Locate the declination cable (the shorter of the two cables) and attach the cable (#21) to the cable holder by tightening the thumb screw on the cable end. The thumb screw should be tightened down hard on the flat surface of the cable holder after backing off the cable about 1/4" from being fully engaged. This method helps ensure there is no slippage when using the cable. You may reverse the position orientation of the Declination cable to suit your preference if desired. Locate the right ascension cable holder (where #18 fits on). Locate the right ascension cable (#18) and attach it the same way as the declination cable was attached in the last section. Slide the counterweight shaft (#9) through the counterweight (#8). Use the counterweight lock (#10) to lock the counterweight in place. By holding the counterweight in one hand, thread the counterweight shaft clockwise into the equatorial mount as shown in figure 1. 2. 3. 4. C. You are now ready to put the telescope optical tube (#2) onto the equatorial mount (#6). The optical tube is held to the mount with two mounting rings. On the bottom of the mounting rings are square extrusions -- one on each ring. This portion of the ring slides over the ends of the mounting platform to hold the telescope in place (see figure 2). 1. Loosen the knurled screws on the side of the mounting rings and remove the tube ring closest to the focuser end of the optical tube. Slide the remaining tube ring towards the objective end of the telescope tube. Place the telescope tube on the mounting platform and orient it so that the objective lens is opposite the slow motion control handles. Slide the attached tube ring down until the square extrusion fits over the end of the mounting platform. Insert one of the mount platform screws through the bottom of the square extrusion and thread it into the mount. Open the second tube ring and place the square extrusion under the other end of the mounting platform. Close the tube and slightly tighten the knurled screw to hold the tube ring in place. Thread the second mounting screw through the square extrusion of the tube ring and into the mounting platform. Tighten both mounting screws. Tighten the knurled screws that clamp the mounting rings in place . This will keep the telescope from sliding back and forth in the mounting rings. 2. 3. 4. 5. 6. 7. 8. 9. D. Put the diagonal (#23) into the focuser (#22) and tighten the thumb screw on the focuser to hold it in place. E. Put the eyepiece (#1) into the diagonal and tighten the thumb screw to hold it in place. 7 3. TELESCOPE OPERATION -GETTING SET UP A. Loosen the polar axis knob (near #5) with one hand while holding the equatorial mount with the other hand. Look at the latitude scale (#19) and move the mount to the latitude of your location and then tighten the polar axis knob. This only has to be done once unless you take the telescope to a different location. For example, Los Angeles, California is located at about 34º. If you do not know your latitude, it can be found on most road atlases of your area. B. To change the direction your telescope is pointing: 1. To move the telescope in declination (north/south) there are two options. For large and quick movements, release the declination knob (near #4) and then tighten the knob when you are near the position you want. For very small movements and fine adjustments, use the declination cable (#21). The declination cable has a range of about 30º and if you come to the stop at the end then overshoot your target by releasing the declination knob and move the telescope in declination. Then tighten the knob and reverse the direction of the declination cable. Do not try to force movement when the declination cable has reached the stop. To move the telescope in right ascension (east/west) there are two options. For large and quick movements, release the right ascension knob (near #5) and then tighten the knob when you are near the position you want. For very small movements and fine adjustments, use the right ascension cable. 2. C. The telescope should be properly balanced in order for it to move smoothly in both axes. Proper balance is essential if using an optional motor drive for accurate tracking. 1. To balance the right ascension axis, move the counterweight shaft so it is parallel (horizontal) to the ground. Slowly release the right ascension knob (near #5) and see if the optical tube moves. If the optical tube moves, then slide the counterweight up or down the counterweight shaft until the optical tube remains stationary in the parallel position to the ground. When this happens, make sure the counterweight lock is tight. D. To quickly move the telescope around horizontally 1. Loosen the horizontal adjustment knob (#16), move the telescope to the position desired and then tighten the knob. E. To focus the telescope. 1. 2. Remove the front lens cover (#3). With a low power eyepiece tight in the diagonal (with its lens cover removed), position the telescope tube to look at any object about one mile or further away during the day. You may need to use the flexible cables to get the object in the center of the field. To focus, turn the focusing knob (#22) until your chosen object is in sharp focus. Remember to use outdoors only as you should not look through windows which may distort the image. F. Attaching the Finderscope: This telescope uses a 6x30 finderscope which is easily attached to the dovetail mount. To attach the finderscope: 1. Attach the finderscope and bracket by sliding the rubber O-ring over the eyepiece end of the finderscope and roll it 2/3 of the way up the finderscope. Then insert the eyepiece end of the finderscope through the bracket until the O-ring presses tightly between the finder and the inside of the bracket. Tighten the three adjustment screws until they make contact with the finderscope body. Slide the finder bracket (attached to the finderscope) into the mounting bracket on the telescope. Tighten the set screw on the mounting bracket to hold the finderscope in place (see figure 3). 8 2. Figure 3 G. Aligning the Finderscope: Do not be alarmed when you look through the telescope and the object is upside down and reversed left to right. This is normal with an astronomical telescope. To align it: 1. 2. 3. 4. Choose a target in excess of one mile away. This will eliminate any possible parallax effect. Point the F80 EQ at your target and center it in the main optics of the telescope. Adjust the screws on the finder bracket until the cross hairs in the finder are centered on the target. Tighten each screw a quarter of a turn so they will not come loose. H. Preparation for astronomical observing requires that you: 1. 2. 3. Orient the telescope so that the right ascension (polar) axis is pointing as close to true north as possible. Use a magnetic compass if you are not sure which way north is. Make sure the mount is level. A carpenters level may be helpful. Recheck all hardware and knobs to make sure all are tight. 4. UNDERSTANDING THE SKY A. The Celestial - Coordinate System. The celestial-coordinate system is an imaginary projection of the Earth's geographical coordinate system onto the celestial sphere which seems to turn overhead at night. This celestial grid is complete with equator, latitudes, longitudes and poles. The Earth is in constant motion as it rotates on its axis. Actually the celestial-coordinate system is being displaced very slowly with respect to the stars. This is called precession and is caused by gravitational influences from the Sun, Moon and other celestial bodies. The celestial equator is a full 360º circle bisecting the celestial sphere into the northern celestial hemisphere and the southern celestial hemisphere Like the Earth's equator, it is the prime parallel of latitude and is designated 0º. 9 The celestial parallels of latitude are called "coordinates of declination (Dec.)", and like the Earth's latitudes they are named for their angular distances from the equator. These distances are measured in degrees, minutes and seconds of arc. There are 60 minutes of arc in each degree, and 60 seconds of arc in each arc minute. Declinations north of the celestial equator are "+" and declinations south are "-". The north pole is +90 and the south pole is -90 . The celestial meridians of longitude are called "coordinates of right ascension (R.A.)", and like the Earth's longitude meridians they extend from pole to pole. There are 24 major R.A. coordinates, evenly spaced around the 360º equator, one every 15º. Like the Earth's longitudes, R.A. coordinates are a measure of time as well as angular distance. We speak of the Earth's major longitude meridians as being separated by one hour of time because the Earth rotates once every 24 hours (one hour = 15°). The same principle applies to celestial longitudes since the celestial sphere appears to rotate once every 24 hours. Right ascension hours are also divided into minutes of arc and seconds of arc, with each hour having 60 minutes of arc and each arc minute being divided into 60 arc seconds. Astronomers prefer the time designation for R.A. coordinates even though the coordinates denote locations on the celestial sphere, because this makes it easier to tell how long it will be before a Figure 4 particular star will cross a particular north-south line in the sky. So, R.A. coordinates are marked off in units of time eastward from an arbitrary point on the celestial equator in the constellation Pisces. The prime R.A. coordinate which passes through this point is designated "O hours O minutes O seconds". We call this reference point the vernal equinox where it crosses the celestial equator. All other coordinates are names for the number of hours, minutes and seconds that they lag behind this coordinate after it passes overhead moving westward. Given the celestial coordinate system, it now becomes possible to find celestial objects by translating their celestial coordinates using telescope pointing positions. For this you use setting circles for R.A. and Dec. to find celestial coordinates for stellar object ...