Celestron CR-150 HD instruction manual StarHopping, Celestial Observing

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StarHopping

StarHopping

You can use your setting circles to find these objects (as described earlier in this manual) or try star hopping. Star hopping is done by using bright stars to guide you to an object. Here are directions for two popular objects.

The Andromeda Galaxy, M31, is an easy first target. To find M31:

1.Locate the constellation of Pegasus, a large square visible in the fall and winter months.

2.Start at the star in the northeast corner. The star is Alpha (α) Andromeda.

3.Move northeast approximately 7°. There you will find two stars of equal brightness — Delta (δ) and Pi (π) Andromeda — about 3° apart.

4.Continue in the same direction another 8°. There you will find two stars — Beta (β) and Mu (µ) Andromeda — 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.

Figure 6-2

Star hopping to the Andromeda Galaxy is a snap to find since all the stars needed to do so are visible to the naked eye. Note that the scale for this star chart is different from the one on the following page which shows the constellation Lyra.

Celestial Observing • 39

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Contents Model #21017 The CR-150HD6 Refractor T A B L E O F C O N T E N T S ii Table of ContentsAssembling the CG-5Equatorial Mount Table of Contents Using the Lens Cap Aperture Stop4 Introduction I N T R O D U C T I O NIntroduction How to Use This Manual AWordofCautionThe Refractor Optical System The Mount6 Introduction Unpacking Your CR-150HD A S S E M B L I N G Y O U R C R - 1 5 0 H DThe CR-150HD Setting Up the Tripod Adjusting the Tripod Height Assembling the CG-5Equatorial MountTripod Head 10 The CR-150HD Attaching the Accessory TrayAttaching the Equatorial Mount 12 The CR-150HD Attaching the R.A. Slow Motion KnobAttaching the Declination Slow Motion Knob 14 The CR-150HD 1.Lock the DEC clamp to hold the mount in placeTube Rings Dovetail Bracket Attaching the Telescope to the Mount16 The CR-150HD Balancing the Telescope in R.ACOMPLETELY Balancing the Telescope in DECAdjusting the Mount in Altitude Adjusting the Mount in Azimuth18 The CR-150HD OPTICAL TUBE Technical SpecificationsDisassembling and Transporting Your CR 150 HD Storing Your CR- 150 HDThe Eyepiece Attaching the AccessoriesT E L E S C O P E B A S I C S The Star DiagonalBuilt-inT-Adapter 1 1/4 AccessoryFocuser Tension AdapterFocusing Attaching the Finder22 Telescope Basics Aligning the Finder NEVER POINT YOUR TELESCOPE AT THE SUN UNLESS Image OrientationYourFirstLook DaytimeObservingNighttime Observing Calculating Magnification Determining Field of View26 Telescope Basics GeneralPhotographyHints Your Celestron telescope can be used for both terrestrial and astronomical photography. Your telescope has a fixed aperture and, as a result, a fixed f/ratio. To properly expose your subjects photographically, you need to set your shutter speed accordingly. Most 35mm single lens reflex SLR cameras offer through-the-lens metering that lets you know if your picture is under or overexposed. This is important for terrestrial photography where exposure times are measured in fractions of a second. In astrophotography, the exposures are much longer, requiring that you use the “B” setting on your camera. The actual exposure time is determined by how long you keep the shutter open. More on this in the section on “Celestial Photography.” A S T R O N O M Y B A S I C S The Celestial Coordi- nate System28 Astronomy Basics Astronomy Basics Motion of the Stars30 Astronomy Basics Polar AlignmentEquator DefinitionFinding the Pole 32 Astronomy Basics Latitude ScalesPointingatPolaris 34 Astronomy Basics DeclinationDriftPolar Alignment Finders Aligning the R.A Setting CircleC E L E S T I A L O B S E R V I N G Observing the MoonObserving the PlanetsCelestial Observing Using the Lens Cap Aperture StopObserving the Sun SOLAROBSERVINGHINTSUsing the Setting Circles Observing Deep-SkyObjects38 Celestial Observing StarHopping 40 Celestial Observing Seeing Viewing ConditionsTransparency Sky Illumination42 Celestial Observing Celestial Photography C E L E S T I A L P H O T O G R A P H YQuarter Short Exposure Prime FocusLunar Phase CrescentThe exposure times listed here should be used as a starting point. Always make exposures that are longer and shorter than the recommended time. Also, try bracketing your exposures, taking a few photos at each shutter speed. This will ensure that you will get a good photo. If using black and white film, try a yellow filter to reduce the light intensity and to increase contrast 46 Celestial Photography PiggybackEktar 1000 color print Konica 3200 color print 48 Celestial Photography Projection PhotographyCare and Cleaning of the Optics T E L E S C O P E M A I N T E N A N C ETelescope Maintenance Super Modified Achromatic SMA Eyepieces 50 Optional AccessoriesO P T I O N A L A C C E S S O R I E S Dual Axis Drive System - #93523Optional Accessories Motor Drive System - #93518 52 Optional AccessoriesType THEMESSIERCATALOGNGC# Const54 The Messier Catalog Proper Name Constellation LIST OF BRIGHT STARSEpoch Star NameGeneral Observational Astronomy FOR FURTHER READINGAstronomy Texts AtlasesCELESTRON ONE YEAR WARRANTY Celestron International 2835 Columbia Street Torrance, CA Tel FaxItem #21017-INST Price $10.00