Celestron 91525, 11055, 11065 instruction manual Nighttime Observing

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Nighttime Observing

Looking at objects in the sky is quite different than looking at objects on Earth. For one, many objects seen in the daytime are easy to see with the naked eye and can be located in the telescope by using landmarks. In the night sky many objects are not visible to the naked eye. To make things easier, you are better off starting with a bright object like the Moon or one of the planets.

1.Orient the telescope so that the polar axis is pointing as close to true north as possible. You can use a landmark that you know faces north to get you in the general direction.

2.Adjust the tripod legs until the mount is level.

3.Adjust the mount until the latitude indicator points to the latitude of the site from which you are observing.

4.Insert a low power eyepiece (i.e., one with a large focal length) into the telescope to give you the widest field possible.

5.Turn the clock drive on.

6.Loosen the right ascension and declination clutch knobs and point the telescope at the desired target. The Moon or one of the brighter planets is an ideal first target.

7.Locate the object in the finder, center it, and then look through the tele- scope.

8.Turn the focus knob until the image is sharp.

9.Take your time and study your subject. If observing the Moon, look for small details in the craters.

That’s all there is to using your Celestron CM-1100. However, don’t limit your view of an object to a single eyepiece. After a few minutes, try using a different optional eyepiece, a more powerful one. This gives you an idea of how the field of view changes. Center your target and focus. Once again, if observing the Moon you will be looking at a few craters at the same time.

NOTE: If not using the clock drive, the stars will appear to drift out of the field of view. This is due to the Earth’s rotation. In fact, anything in the sky, day or night, will drift out unless the telescope has been polar aligned and the clock drive is running. There is more on this in the section on “Polar Alignment.”

26 • Telescope Basics

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Contents Page E C e l e s t r o n C M- 11 00/1400 B L E O F C O N T E N T S Iv Table of Contents T R O D U C T I O N How to Use This Manual Word of Caution Schmidt-Cassegrain Optical System S E M B L I N G Y O U R C M 1 1 0 Unpacking Your Celestron CM-1100CM-1100 Setting Up the Tripod Attaching the Center Leg Brace Attaching the Central Column Central Column Electronics Console Center Leg BraceAttaching the Equatorial Mount Installing Counterweight Bar Installing CounterweightAttaching the Optical Tube to the Mount Attaching the Visual Back Installing the Star Diagonal Assembling Your CM-1100 Installing the Finder Installing the Polar Finder Moving the Telescope in R.A. and DEC Adjusting the Mount Balancing the Mount in R.A Balancing the Mount in DEC Assembling Your CM-1100 Technical Specifications Tripod L E S C O P E B a S I C S Image Orientation Focusing General Photography Hints Aligning the Finder Your First Look Daytime ObservingNighttime Observing Calculating Magnification Determining Field of View T R O N O M Y B a S I C S Celestial Coordinate SystemMotion of the Stars Polar Alignment DefinitionFinding the Pole Latitude Scales Pointing at Polaris Polar Axis Finder Declination Drift Aligning the R.A. Setting Circle Setting the DEC Circle Powering Up the Drive I N G T H E D R I V EGuide Speed Periodic Error Correc- tion BC Backlash CorrectionHC/CCD Northern/Southern Hemisphere Operation Hand ControllerDEC Reverse AutoguidingL E S T I a L O B S E R V I N G Observing the MoonObserving the Sun Using Your Setting Circles Observing Deep-Sky ObjectsStar Hopping Celestial Observing Sky Illumination Viewing ConditionsTransparency Seeing ConditionsCelestial Observing L E S T I a L P H O T O G R a P H Y Lunar Phase ISO Crescent Quarter Short Exposure Prime FocusFull Celestial Photography Piggyback Celestial Photography Eyepiece Projection Planet ISO Moon Mercury Venus Mars Jupiter Saturn Long Exposure Prime Focus Celestial Photography CCD Imaging Fastar Configuration Description of F-numbersImaging at f/7 Imaging at f/11 Medium size to small galaxiesLunar or small planetary nebulae Imaging at f/22 Planetary or LunarCare and Cleaning of the Optics Collimation L E S C O P E M a I N T E N a N C ETelescope Maintenance Telescope Maintenance T I O N a L a C C E S S O R I E S Optional Accessories Optional Accessories Optional Accessories Const Mag Type Proper NameNGC# Spiral Galaxy Epoch Star Name Constellation MagnitudeGeneral Observational Astronomy Astronomy TextsAtlases Visual ObservationCelestron ONE Year Warranty