Celestron 31056, Instruction Manual

Page 1: ...C150 HD AND G 8N NEWTONIAN INSTRUCTION MANUAL Models 31056 and 31058 ...

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Page 3: ...scope in DEC 20 Adjusting the Mount in Altitude 21 Adjusting the Mount in Azimuth 21 Disassembling and Transporting Your G 8N 22 Storing Your Telescope 22 Installing the Finderscope 23 Installing the Eyepiece 24 Technical Specifications 25 TELESCOPE BASICS 26 Image Orientation 26 Focusing 27 Aligning the Finder 28 Your First Look 29 Daytime Observing 29 Nighttime Observing 30 Calculating Magnifica...

Page 4: ... Hopping 43 Viewing Conditions 45 Transparency 45 Sky Illumination 45 Seeing 45 CELESTIALPHOTOGRAPHY 47 Short Exposure Prime Focus 48 Piggyback 49 TELESCOPEMAINTENANCE 51 Care and Cleaning of the Optics 51 Collimation 51 OPTIONALACCESSORIES 53 THE MESSIER CATALOG 56 LIST OF BRIGHT STARS 59 FORFURTHERREADING 60 ii Table of Contents ...

Page 5: ... its 8 diameter mirror gathers almost 800 times the light of your eye It can show you literally thousands of deep sky objects Yet your Celestron Newtonian telescope is compact enough to take to the mountains or desert or wherever you observe This telescope is made of the highest quality materials to ensure durability and stability All this adds up to a telescope that gives you a lifetime of pleasu...

Page 6: ...e challenging observations The final part of this manual contains a list of objects that can be observed through your Celestron telescope Included are the coordinates for each object its brightness and a code which indicates what type of an object it is In addition there is a list of bright stars used for aligning the setting circles Read the assembly instructions through completely before you att...

Page 7: ... telescope uses a primary mirror to focus the light rays it collects In addition to focusing the light the mirror also redirects them toward the front of the telescope tube where the light entered Near the front of the tube the light rays are intercepted by a small flat secondary mirror some times called an elliptical flat and directed out of the telescope tube at a 90 angle to the incoming light ...

Page 8: ...German Equatorial Mount Model 31056 CG 5 German Equatorial Mount Model 31058 Counterweight Bar Counterweight 5 kg for Model 31058 3 6kg and 1 8kg for Model 31056 Declination DEC Slow Motion Knob Right Ascension R A Slow Motion Knob Adjustable Aluminium Tripod Accessory Tray When setting up the telescope find a large clear area where the parts can be laid out without fear of losing them Start with ...

Page 9: ...e Assembly 3 Tube Ring 11 Counterweight 4 PiggybackAdapter 12 CounterweightShaft 5 Latitude Scale 13 EquatorialMount 6 LatitudeAdjustmentScrew 14 Focuser 7 Tripod 15 Eyepiece 8 Accessory Tray Figure 2 1 G 8N with CG 5 Equatorial Mount The G 8N 1 2 3 5 6 7 9 10 12 13 8 14 15 4 ...

Page 10: ... Ring 11 CounterweightShaft 4 PrimaryMirror insidetube 12 Declination Circle 5 SolwMotionCables 13 MountingPlatform 6 Latitude Scale 14 Eyepiece 7 LatitudeAdjustmentScrew 15 SecondaryMirror 8 Tripod The C150 HD 1 2 3 5 7 8 4 9 10 12 13 14 15 6 11 Figure2 1A C150 HD with CG 4 Equatorial Mount ...

Page 11: ...flexure or wobble of the legs Once the tripod is set up you can adjust the height at which it stands To do this 1 Loosen the knob on the leg clamp so that the tripod leg can be adjusted 2 Slide the center portion of the tripod leg away from the tripod head until it is at the desired height 3 Tighten the knobs on each leg clamp to hold the legs in place With the tripod set up you are ready to attac...

Page 12: ...les in the accessory tray are above the slotted holes in the bracket 3 Insert the wing bolts up through the slotted holes in the leg brace see figure 2 3 4 Thread the wing bolts into the holes in the accessory tray 5 Tighten the wing bolts fully With the accessory tray in place the tripod will be much more stable making it easier to attach the mount and telescope Attaching the Accessory Tray Figur...

Page 13: ...points straight up To attach the equatorial head 1 Locate the azimuth adjustment screws on the equatorial mount 2 Retract the screws so they no longer extend into the azimuth housing rectangular extrusion on the mount Do NOT remove the screws since they are needed later for polar alignment 3 Hold the equatorial mount over the tripod head so that the azimuth housing is above the metal peg 4 Place t...

Page 14: ... the R A shaft 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 more convenient If after a few observing sessions you find the R A slow motion knob is more accessibl...

Page 15: ...tion 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 Use the shaft that is pointing toward the ground This makes it easy to reach while looking through the telescope something which is quite important when you are observing 1 Line up the flat area on the inner portion of the DEC slow motion knob with the flat ar...

Page 16: ...ounterweight bar is now installed With the counterweight bar in place you are ready to attach the counterweight 1 Lock the DEC clamp to hold the mount in place 2 Remove the safety thumbscrew on the end of the counterweight bar 3 Loosen the set screw on the counterweight itself so that the central hole of the counterweight is unobstructed 4 Slide the counterweight onto the counterweight bar see fig...

Page 17: ...op of the mounting platform see figure 2 8 5 Tighten the telescope mounting screw on the CG 5 mount to hold the telescope in place 6 Hand tighten the mounting platform safety screw until the tip touches the side of the mounting bracket see figure 2 5 NOTE Never loosen any of the knobs on the telescope tube or mount Also be sure that the open end of the telescope is pointing away from the ground at...

Page 18: ...nd slide the mounting rings until they are over the holes on the mounting platform 4 Place the flat portion of the ring over the mount so that the hole in the ring is over the holes of the mounting platform 5 Thread the mounting screws underneath the mounting platform to secure the rings Tighten the knobs on the side of the mounting rings to prevent the telescope from sliding forward or backward T...

Page 19: ...ope off to one side of the mount make sure that the mounting bracket screw is tight The counter weight bar will extend horizontally on the opposite side of the mount see figure 2 9 2 Release the telescope GRADUALLY to see which way the telescope rolls 3 Loosen the set screw on the counterweight 4 Move the counterweight to a point where it balances the telescope i e it remains stationary when the R...

Page 20: ...around the declination axis DO NOT LET GO OF THE TELESCOPE TUBE COMPLETELY 5 Loosen the screws that hold the telescope tube inside the mounting rings and slide the telescope either forwards or backwards until it remains stationary when the DEC clamp is released 6 Tighten the tude ring screws firmly to hold the telescope in place Like the R A balance these are general balance instructions and will ...

Page 21: ... axis is pointing The latitude adjustment on the CG 4 and CG 5 mount has a range of 40 starting at 20 going up to 60 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 screws located on either side of the azimuth housing at the base of the mount While standing behind the telescope the knobs are on the f...

Page 22: ...the telescope yourself However you may want to remove the counterweight from the counterweight bar to lighten the mount If you are shipping the telescope via a common carrier you should completely disassemble the telescope and return all parts to their original shipping container When not in use your Celestron telescope can be left fully assembled and set up However all lens and eyepiece covers sh...

Page 23: ...hrough the bracket until the O ring presses tightly between the finder and the inside of the bracket 3 Tighten the adjustment screws until they make contact with the finderscope body 4 Locate the mounting bracket near the front open end of the telescope 5 Loosen the set screw on the mounting bracket on the telescope 6 Slide the finder bracket attached to the finderscope into the mounting bracket o...

Page 24: ...lar Eyepieces are commonly referred to by focal length which is printed on the eyepiece barrel The longer the focal length i e the larger the number the lower the eyepiece power and the shorter the focal length i e the smaller the number the higher the magnification Generally you will use low to moder ate power when viewing For more information on how to determine power see the section on Calculat...

Page 25: ...al Length 1000mm 40 750mm 30 Highest Useful Power 480x 360x Resolution arc seconds 0 58 77 Light Gathering Power 816 459 Limiting Visual Magnitude 14 13 5 Secondary Obstruction 2 9 2 2 of Primary Surface Area 13 1 13 4 f ratio f 5 f 5 Length 19 75 14 5 Weight Optical Tube 15 5 lb 8 5 lb With Tripod 30 5 lb 25lb These specifications are approximate and subject to change without notice Technical Spe...

Page 26: ...ffect your terrestrial observations For celestial viewing star charts can be made to match the view in the telescope by rotating the chart 180 about the center The view through the finder is also inverted Image Orientation ActualVeiw NewtonianView Figure 3 1 The figure illustrate the image orientation of a Newtonian telescope Top is the actual orientation while below is the image seen through the ...

Page 27: ... focus In some cases you may actually see a double image Never look across or over objects that are producing heat waves This includes asphalt parking lots on hot summer days or building roof tops Hazy skies fog and mist can also make it difficult to focus The amount of detail that can be seen under these conditions will be greatly reduced When using your telescope as a telephoto lens the split sc...

Page 28: ...ease the R A and DEC clamps and point the telescope at your target 3 Center your target in the main optics of the telescope You may have to move the telescope slightly to center it 4 Adjust the screw on the finder bracket that is on the right when looking through the finder until the cross hairs are centered horizontally on the target seen through the telescope 5 Adjust the screw on the top of the...

Page 29: ... and DEC clamps and point the telescope at the object you selected 4 Locate the object in your finder and lock the R A and DEC clamps 5 Use the slow motion knobs to center the object in the field of the finder 6 Once centered look through your telescope and the object will be there if you aligned the finder first Try using different optional eyepieces to see how the field changes with various magn...

Page 30: ...orth as possible You can use a landmark that you know faces north to get you in the general direction 2 Adjust the mount until the latitude indicator points to the latitude from which you are observing 3 Insert an eyepiece into the telescope It should be a low power eyepiece i e one with a large number on the side to give you the widest field possible 4 Turn the motor drive on if you are using one...

Page 31: ...nge of 20 to 35 power for every inch of aperture which for the G 8N is between 160 and 280 power 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 actual field of view divide the apparent field of the eyepiece supplied by the eyepiece manufacturer by the magnification As you can see before you determine the fi...

Page 32: ...tor carry a minus sign in front of the number and those north are often preceded by a plus sign The celestial equivalent of longitude is called Right Ascension or R A for short Like the Earth s lines of longitude they run from pole to pole and are evenly spaced 15 degrees apart Although the longitude lines are separated by an angular distance they are also a measure of time Each line of longitude ...

Page 33: ... see the stars complete one circle because the sunlight during the day washes out the starlight However part of this circular motion of stars in this region of the sky can be seen by setting up a camera on a tripod and opening the shutter for a couple of hours The processed film will reveal circular arcs that are centered on the pole This information will be useful for certain methods of polar ali...

Page 34: ...h the telescope will appear stationary i e they will not drift out of the field of view If your telescope does not use a motor drive all objects in the sky day or night will drift out of the field This apparent motion is caused by the Earth s rotation Even if you are not using a motor drive polar alignment is still desirable since it will reduce the number of corrections needed to follow an object...

Page 35: ...Big Dipper will change during the year and throughout the course of the night see figure 4 4 When the Big Dipper is difficult to locate try using Cassiopia Observers in the southern hemisphere are not as fortunate as those in the northern hemisphere The stars around the south celestial pole are not nearly as bright as those around the north The closest star that is relatively bright is Sigma Octan...

Page 36: ...northern horizon This means the pole is now 89 above the northern horizon If you move one degree further south the same thing happens again As you can see from this example the distance from the northern horizon to the celestial pole is always equal to your latitude If you are observing from Los Angeles which has a latitude of 34 then the celestial pole would be 34 above the northern horizon All a...

Page 37: ...e the telescope so that the optical tube is directly over the polar axis see figure 4 6 3 Move the mount in altitude and or azimuth until Polaris is in the field of view of the finder Rough azimuth adjustments can be made by moving the tripod 4 Center Polaris using the fine altitude and azimuth controls refer to figure 2 5 Remember do not move the telescope in R A or DEC You want to adjust the dir...

Page 38: ...g due south with the scope on the side of the mount insert the diagonal so it points straight up Insert a cross hair ocular and align the cross hairs to be parallel to declination and right ascension motion First choose your star near where the celestial equator and the meridian meet The star should be approximately 1 2 hour of the meridian and 5 degrees of the celestial equator Center the star in...

Page 39: ...sing the Celestron Sky Maps 93722 or consulting a current as tronomy magazine To align the R A setting circle 1 Locate a bright star near the celestial equator The farther you are from the celestial pole the better your reading on the R A setting circle will be The star you choose to align the setting circle with should be a bright one whose coordinates are known and easy to look up For a list of ...

Page 40: ...effect is more noticeable at higher power If you are using a motor drive and have polar aligned the Moon will remain centered Consult your local newspaper or a current astronomy magazine to find out when the Moon will be visible Try using filters to increase contrast and bring out more detail on the lunar surface Other easy targets in the night sky include the five naked eye planets You can see Ve...

Page 41: ...tch the shadow of the telescope tube until it forms a circular shadow Deep sky objects are simply those objects outside the boundaries of our solar system They include star clusters planetary nebulae diffuse nebulae double stars and other galaxies outside our own Milky Way The Celestron Sky Maps 93722 can help you locate the brightest deep sky objects Most deep sky objects have a large angular siz...

Page 42: ...locked position 5 Look through the finder to see if you have located the object 6 Center the object in the finder 7 Look in the main optics using a low power eyepiece the object should be there The telescope will track in R A as long as the motor drive is operating 8 Repeat the process for each object observed throughout the observing session You may not be able to see fainter objects in the finde...

Page 43: ... corner The star is Alpha α Andromedae 3 Move northeast approximately 7 There you will find two stars of equal brightness Delta δ and Pi π Andromedae about 3 apart 4 Continue in the same direction another 8 There you will find two stars Beta β and Mu µ Andromedae about 3 apart 5 Move 3 northwest the same distance between the two stars to the Andromeda galaxy It is easily visible in the finder Figu...

Page 44: ...stars that make up the parallelogram Beta β and Gamma γ Lyrae see figure 5 3 4 Point the finder half way between these two stars 5 Move about 1 2 toward Beta β Lyrae but remaining on a line that connects the two stars 6 Look through the telescope and the Ring Nebula should be in the tele scope Its angular size is quite small and therefore not visible in the finder These two examples should give yo...

Page 45: ...eeing conditions refer to the stability of the atmosphere and directly effects the clarity of star images and the amount of fine detail seen in extended objects like the planets 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 Li...

Page 46: ...tend to produce good seeing If you can t get a better location wait until the early morning hours when the surroundings are uniformly cool and the seeing is generally better Type 3 seeing conditions are characterized by fast ripples but sharp images In extended objects fine detail is visible but the images shift around the field Stars are crisp points but they shift small distances rapidly around ...

Page 47: ...re the mandatory features a camera needs for celestial photog raphy First a B setting which allows for time exposures This excludes point and shoot cameras and limits the selection to 35mm SLR cameras Second the B or manual setting should not run off the battery Many new electronic cameras use the battery to keep the shutter open during time exposures Once the batteries are drained usually after a...

Page 48: ...amera body onto the T Ring the same as you would any other lens With your camera attached to the telescope you are ready for prime focus photography Start with an easy object like the Moon Here s how to do it 1 Load your camera with film that has a moderate to fast speed i e ISO rating Faster films are more desirable when the Moon is a crescent When the Moon is near full and at its brightest slowe...

Page 49: ... mounting ring see figure2 1 It will be neccessary to remove the finder scope bracket before attaching the camera In order to guide the exposure you will need an optional motor drive 93518 or 93523 As with any form of deep sky photography it should be done from a dark sky observing site Light pollution around major urban areas washes out the faint light of deep sky objects You can still practice f...

Page 50: ...a 3200 color print Fujichrome 1600D color slide 3M 1000 color slide T Max 3200 black and white print T Max 400 black and white print As you perfect your technique try specialized films that is films that are designed or specially treated for celestial photography Here are some popular choices Ektar 125 color print Fujichrome 100D color slide Tech Pan gas hypered black and white print As with all f...

Page 51: ... you should check collimation to ensure that rough handling has not altered the alignment of the mirrors To determine whether or not recollimation is necessary the telescope should be set up outside at night It should be a still night and one in which you have let the telescope sit outside for 30 to 45 minutes before attempting collimation You should also wait for a night with good seeing conditio...

Page 52: ...e the star from the center to about half way or less toward the field s edge for higher power oculars Prior to making any adjustment it is advisable to gently back off the pressure on the three 3 outer screws to where they are snug yet easily loosened without moving the telescope unnecessarily Collimation adjustments are best made while viewing the star s position in the field of view while turnin...

Page 53: ...of celestial objects producing the best possible image sharpness Drive correctors are a must for those with serious interest in astrophotography or CCD imaging This precision state of the art DC motor drive operates on D Cell batteries The hand controller module is very compact and fits easily in the palm of your hand Motors for both axes are included along with brackets clutches and hardware Eyep...

Page 54: ...pe in that you can use both eyes when pointing the telescope at an object A partially reflective surface projects the image of an LED illuminated pinpoint into the line of sight Just align the illuminated pinpoint with the object you are interested in and the object will be in the main telescope Night Vision Flashlight 93588 Celestron s premium model for as tronomy using two red LEDs to preserve n...

Page 55: ...from which you re observing For 20 to 40 of latitude 93720 30 For 30 to 50 of latitude 93720 40 For 40 to 60 of latitude 93720 50 Polarizing Filter Set 93608 The polarizing filter set limits the transmis sion of light to a specific plane thus increasing contrast between various objects This is used primarily for terrestrial lunar and planetary observing Polar Axis Finderscope 94221 This useful acc...

Page 56: ...6523 Sgr 18 03 7 24 23 5 8 D Neb LagoonNebula M9 NGC6333 Oph 17 19 2 18 31 7 9 Gl Cl M10 NGC6254 Oph 16 57 2 4 06 6 6 Gl Cl M11 NGC6705 Sct 18 51 1 6 16 5 8 Op Cl Wild Duck Cluster M12 NGC6218 Oph 16 47 2 1 57 6 6 Gl Cl M13 NGC6205 Her 16 41 7 36 28 5 9 Gl Cl Hercules Cluster M14 NGC6402 Oph 17 37 6 3 15 7 6 Gl Cl M15 NGC7078 Peg 21 30 0 12 10 6 4 Gl Cl M16 NGC6611 Ser 18 18 9 13 47 6 0 D Neb Eagl...

Page 57: ...024 Com 13 12 9 18 10 7 7 Gl Cl M54 NGC6715 Sgr 18 55 1 30 29 7 7 Gl Cl M55 NGC6809 Sgr 19 40 0 30 58 7 0 Gl Cl M56 NGC6779 Lyr 19 16 6 30 11 8 2 Gl Cl M57 NGC6720 Lyr 18 53 6 33 02 9 0 P Neb RingNebula M58 NGC4579 Vir 12 37 7 11 49 9 8 Sp Gx M59 NGC4621 Vir 12 42 0 11 39 9 8 El Gx M60 NGC4649 Vir 12 43 7 11 33 8 8 El Gx M61 NGC4303 Vir 12 21 9 4 28 9 7 Sp Gx M62 NGC6266 Oph 17 01 2 30 07 6 6 Gl C...

Page 58: ...GC4736 CVn 12 50 9 41 07 8 1 Sp Gx M95 NGC3351 Leo 10 44 0 11 42 9 7 Sp Gx M96 NGC3368 Leo 10 46 8 11 49 9 2 Sp Gx M97 NGC3587 UMa 11 14 9 55 01 11 2 P Neb OwlNebula M98 NGC4192 Com 12 13 8 14 54 10 1 Sp Gx M99 NGC4254 Com 12 18 8 14 25 9 8 Sp Gx Pin Wheel Nebula M100 NGC4321 Com 12 22 9 15 49 9 4 Sp Gx M101 NGC5457 UMa 14 03 2 54 21 7 7 Sp Gx M102 NGC5457 UMa 14 03 2 54 21 7 7 dup M103 NGC581 Cas...

Page 59: ...H M S H M S H M S H M S H M S Sirius CMa 06 45 09 16 42 58 1 47 Canopus Car 06 23 57 52 41 44 0 72 Arcturus Boo 14 15 40 19 10 57 0 72 Rigel Kent Cen 14 39 37 60 50 02 0 01 Vega Lyr 18 36 56 38 47 01 0 04 Capella Aur 05 16 41 45 59 53 0 05 Rigel Ori 05 14 32 08 12 06 0 14 Procyon CMi 07 38 18 05 13 30 0 37 Betelgeuse Ori 05 55 10 07 24 26 0 41 Achernar Eri 01 37 43 57 14 12 0 60 Hadar Cen 14 03 49...

Page 60: ...kinson Costanzo Chaple NGC 2000 0 Sinnott General Observational Astronomy The Cambridge Astronomy Guide Liller Mayer A Complete Manual Of Amateur Astronomy Sherrod The Guide To Amateur Astronomy Newton Teece Visual Observation Observational Astronomy For Amateurs Sidgwick Astronomical Calendar Ottewell Burnham s Celestial Handbook Vols 1 2 3 Burnham The Planet Jupiter Peek Field Guide To The Stars...

Page 61: ...dling or unauthorized repair Further product malfunction or deterioration due to normal wear is not covered by this warranty CELESTRON DISCLAIMS ANY WARRANTIES EXPRESS OR IMPLIED WHETHER OF MERCHANTABILITY OF FITNESS FOR A PARTICULAR USE EXCEPT AS EXPRESSLY SET FORTH HEREIN THE SOLE OBLIGATION OF CELESTRON UNDER THIS LIMITED WARRANTY SHALL BE TO REPAIR OR REPLACE THE COVERED PRODUCT IN ACCORDANCE ...

Page 62: ...reet Torrance CA 90503 Tel 310 328 9560 Fax 310 212 5835 www celestron com Copyright 2002 Celestron All rights reserved Products or instructions may change without notice or obligation Item 31058 INST 08 02 Price 10 00 ...