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ASTRONOMY FORMULAS FOR YOUR 

ZHUMELL AURORA TELESCOPE

MAGNIFICATION

To determine the magnification of a telescope and eyepiece 
combinantion, divide the telescope focal length be the eye-
piece focal length.

Magnification (x) = Telescope Focal Length (mm)/Eyepiece 
Focal Length (mm)

 

Ex: 20mm Eyepiece with a 70x900mm telescope.   

 

Magnification = 900mm/20mm

 

Magnification = 45x

FOCAL RATIO

To determine the focal ratio of a telescope, divide the focal 
length of the telescope by the aperture.

Focal Ratio (f/x)= Telescope Focal Length (mm)/Aperture (mm)

 

Ex: Focal Ratio of a 70x900mm telescope.

 

Focal Ratio (f/x)= 900mm/70mm

 

Focal Ratio (f/x)= f/12.9

Summary of Contents for AURORA 70

Page 1: ...0 1 5 W 30 W 45 W 60 W 1 5 E 75 W OWNER S MANUAL AURORA TELESCOPE ZHUMELL AURORA 70 WITH MOTOR DRIVE REFLECTOR TELESCOPE ...

Page 2: ...ell you get field tested precision crafted optics at the best possible value So even if you re just starting out as an amateur birder or astronomer you don t have to settle for entry level products Zhumell customers enjoy life s pursuits hobbies and adventures in rich colorful detail the kind of detail that only high performance optics can produce At Zhumell we design our binoculars telescopes and...

Page 3: ...s 9 Advanced Observation 10 Astronomy Formulas 11 Astronomy Terminology 12 Telescope Terminology 13 Warranty i Checking and Aligning Your Finderscope ii Using the Motor Drive iii Manual Adjustment with Motor Drive i Getting Started Adjustments ii Polar Alignment iii Finding Celestial Objects a Northern Hemisphere Polaris b Southern Hemisphere Star Drift i Rough Alignment ii Star Drift Alignment i ...

Page 4: ...tor Telescope is built with the highest quality optics and top notch construction to provide years of reliable functionality but will require proper care If after reading this manual you still have questions about your Zhumell telescope please visit http www zhumell com for more helpful tips and contact information Our customer service representatives are available to address any problems you enco...

Page 5: ...age Never use an eyepiece filter as a solar filter Only solar filters will completely cover the opening of the optical tube and provide proper eye protection Make sure no screws are loose before using telescope Do not drop or shake your telescope as doing so may damage the optics or harm you or the people around you CARING FOR YOUR ZHUMELL AURORA TELESCOPE ...

Page 6: ... 1 Brush telescope optics with camelhair brush or blow off dust with an ear syringe can be purchased at any pharmacy Do not use a commercial photographic lens cleaner 2 Remove organic materials e g fingerprints with short gentle strokes using soft white tissue paper and a solution of three parts distilled water and one part isopropyl alcohol You may also add one drop of biodegradable dish soap to ...

Page 7: ... Length 900 Limiting Magnitude 11 7 Focal Ratio f 12 9 Eyepiece Format 1 25 Finderscope 5 24 Mount Type Equatorial OPTICAL TUBE ASSEMBLY MOUNT ASSEMBLY Materials Aluminum R A Adjustment Manual Worm Gear Dec Adjustment Manual Worm Gear Clock Drive Axis R A Clock Drive Power 2 9V Batteries ...

Page 8: ...ly OTA OTA Mounting Bracket 5x24 Finderscope Finderscope Mounting Bracket Equatorial Mount Adjustable Speed Motor Drive Right Ascension and Declination Adjustment Cables Counterweight with rod Aluminum Tripod Accessory Tray Diagonal Lens 9mm and 20mm Kellner Eyepieces ...

Page 9: ...tor Drive LEGEND FOR YOUR ZHUMELL AURORA TELESCOPE 7 Latitudinal Adjustment Screws 8 Base Mount Screw 9 Right Ascension Adjustment Cable 10 Declination Adjustment Cable 11 Hour Circle 12 Declination Circle 13 Counterweight 14 Aluminum Tripod 15 Accessory Tray not pictured 16 Diagonal Lens 17 Eyepiece 3 6 8 13 2 11 12 9 1 17 14 4 16 10 7 5 ...

Page 10: ...g Tighten each leg at a height where you will be able to stand comfortably during the rest of assembly just above waist high Make sure they are tightened evenly so that the top of the Tripod is parallel to the ground ATTACHING THE EQUATORIAL MOUNT STEP 1 Remove the Base Mount Screw from the bottom of the mount leaving the attached washer in place Insert the mount into the hole in the middle of the...

Page 11: ... thumbscrew on the second straight bracket on the Motor Drive and slide onto corre sponding bolt about 2 5 inches up the mount Securely fastening the Motor Drive in both of these locations is essential to proper function STEP 1 Loosen the thumbscrew on the longer cable This is the Right Ascension Adjustment Cable Slide it over the exposed bolt nearest the top of the mount and tighten with the atta...

Page 12: ...1 Slide the connecting rod through the Counterweight body and tighten using the attached thumbscrew STEP 2 Screw the connecting rod into the mount When in place it should not move and should be facing downward at an angle CONNECTING THE OTA MOUNTING BRACKET TO THE EQUATORIAL MOUNT STEP 1 Remove the 2 thumbscrews on the OTA Mounting Bracket and slide the exposed bolts through the corresponding hole...

Page 13: ... its weight with your hand Close the OTA Mounting Bracket over the OTA and tighten the screw until it is firm and secure ATTACHING THE FINDERSCOPE STEP 1 Locate the two screws on top of the OTA near the lower end Remove the heads of these screws and place the Finderscope Bracket using the corresponding holes Fasten securely with the heads ASSEMBLY OF YOUR ZHUMELL AURORA TELESCOPE 7 7 ...

Page 14: ...of your telescope Slide the Diagonal Lens in silver side first and tighten the thumbscrew until secure Do not let go of the Diagonal Lens until the thumbscrew has been fastened tightly USING AN EYEPIECE STEP 1 You will need to attach an eyepiece to use your telescope Choose one of the included 1 25 inch eyepieces and slide it into the Diagonal Lens silver side first Secure the connection using the...

Page 15: ...n color found in such dim images The lack of color is due to human anatomy not any limitations of telescope construction CHECKING AND ALIGNING YOUR FINDERSCOPE Finderscope alignment is the first step to fine tuning your Aurora 70 setup and viewing celestial objects Follow these steps to properly set up and align your finderscope 1 Insert the lowest power eyepiece into the Diagonal Lens Focus eyepi...

Page 16: ...y and the motion of your scope will be subtle To test if your motor drive is working aim your telescope at a stationary object and turn on the motor drive After 15 minutes look through your telescope again if it is no longer pointing exactly where you originally aimed it the motor drive is working MOTOR DRIVE SETTINGS The motor drive features two controls that must be set depending on your viewing...

Page 17: ...ve on VIEWING THROUGH YOUR ZHUMELL AURORA TELESCOPE BEGINNING OBSERVATION THE MOON As you set out to begin viewing one of the easiest and most enjoyable objects to look at is the moon Finding the moon and adjusting to view it is a good way to acquaint yourself with the movements of your telescope Follow these steps carefully to gain a basic understanding of the adjustments you can make to your sco...

Page 18: ...sembly past the stop Be sure to retighten the clamps before viewing If you notice resistance while moving the Optical Tube Assembly try adjusting the counterweight position up or down to properly balance the telescope The OTA should move very easily and smoothly never try and force the OTA to move as this can permanently damage your telescope Once you ve located the moon and successfully pointed y...

Page 19: ...n any given night To find a planet you must first locate it with the naked eye Once you ve got its general location point your telescope in that direction and center the planet in the crosshairs of your finderscope Once the planet is lined up in the finderscope begin to view the planet through your telescope using the lowest power longest focal length eyepiece You may need to make slight adjustmen...

Page 20: ...on your Equatorial Mount You can adjust Declination and Right Ascension astronomical equivalents to latitude and longitude both in large scale movements and slow motion fine tuning movements The procedure for each is explained below Large scale movement along the longitudinal axis Right Ascension is achieved using the Mount Base Screw This is the lowermost knob on your mount Loosen the mount base ...

Page 21: ... is the Declination Scale After setting the telescope angle using the Latitudinal Adjustment Screws the fine tuned adjustments can be made using the Declination Adjustment Cable Declination is measured from 0 to 90 each direction Before beginning polar alignment it is important to ensure that the base of your mount is level If the base is not level by even the smallest degree your measurements wil...

Page 22: ...ipper will roughly point at Polaris You can also use the star at the end of the handle of the Big Dipper and the star on the edge on the shallower end of Cassiopeia to draw a line through Polaris Only move on to the next step when you have successfully located Polaris 2 Loosen the thumbscrew on the Declination Adjustment Cable Lower the OTA so that the arrow in the Declination Scale points at 0 On...

Page 23: ...atitude scale check to make sure that your tripod is level and continue adjustment 5 Your telescope is now polar aligned or set with the North Star as zero All adjustments you make to find other celestial objects will be based off of this location Happy hunting SOUTHERN HEMISPHERE STAR DRIFT POLAR ALIGNMENT Polar alignment in the Southern Hemisphere is more difficult than in the Northern Hemispher...

Page 24: ...nd effort For general purpose viewing the rough alignment described above may prove to be sufficient Star drift alignment as described below can be used for more accurate alignment and is described using a standard eyepiece without an erecting prism 1 After rough alignment loosen the Latitudinal Adjustment Screws and lower your telescope until the scale reads 90 then retighten the screw Loosen the...

Page 25: ...ount Base Screw and re center the star in the eyepiece Any drifting up and down in the eyepiece is a result of your motor drive speed setting and can be corrected by adjusting the motor drive speed 5 Disengage the motor drive Loosen the Mount Base Screw and rotate the telescope back 6 hours opposite the direction you rotated it in Step 1 Find another bright star in the viewfinder and center it in ...

Page 26: ...e s used for initial polar alignment SETTING THE HOUR CIRCLE To set the hour circle choose an easily identifiable star for which you know the coordinates In the Northern Hemisphere a reliable choice is Dubhe Dubhe is the pointer star in the Big Dipper closest to Polaris and lies at 58 42 Dec 11h23m R A In the Southern Hemisphere a good choice is the star Acrux Acrux is the closest star to the sout...

Page 27: ...ckly and accurately Remember make large scale adjustments using the Base Mount Screw and Latitudinal Adjustment Screws and fine tuned adjustments using the R A and Declination adjustment cables USING MOTOR DRIVE Once you ve centered your telescope on a celestial object and begin observing it remember that it will move through the night sky Engage your motor drive once focused on an object and it w...

Page 28: ...Magnification x Telescope Focal Length mm Eyepiece Focal Length mm Ex 20mm Eyepiece with a 70x900mm telescope Magnification 900mm 20mm Magnification 45x FOCAL RATIO To determine the focal ratio of a telescope divide the focal length of the telescope by the aperture Focal Ratio f x Telescope Focal Length mm Aperture mm Ex Focal Ratio of a 70x900mm telescope Focal Ratio f x 900mm 70mm Focal Ratio f ...

Page 29: ...ture in cm Ex Limiting Magnitude of a 70x900mm telescope Limiting Magnitude 7 5 5LOG 7cm Limiting Magnitude 7 5 5 x 845 Limiting Magnitude 11 72 RESOLVING POWER To determine the resolving power of a telescope under ideal conditions divide the aperture into 4 56 Resolving Power 4 56 Aperture in inches Ex Resolving Power of a 70x900mm telescope Aperture in 70mm 25 4 2 75 in Resolving Power 4 56 2 75...

Page 30: ... equinox is where right ascension is at 0h hours The autumnal equinox can be found at 12h R A ZENITH The zenith is the point in the celestial sphere directly above your head The zenith varies depending upon your location In general the declination point of your zenith is equal to the latitude at which you are standing on Earth EPHEMERIS The ephemeris of a planet or the sun or the moon is a table g...

Page 31: ...o called f stop provides a wider field of view Photographically the lower the f stop the shorter the exposure time needed to capture an object on film LIMITING MAGNITUDE The limiting magnitude of a telescope describes the faintest object you can see with a telescope The magnitude of a star describes its brightness The larger the magnitude of an object the fainter it appears to be The brightest sta...

Page 32: ...ranty To obtain warranty service the damaged equipment must be returned to Zhumell Our Customer Care associates will be happy to assist you in completing this return to get your Zhumell in working order as quickly as possible There is a 25 surcharge associated with warranty returns to cover return shipping and handling For more information contact information and to download the Zhumell Warranty R...

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