Celestron CR-150 HD Observing the Moon, Planets, C E L E S T I A L O B S E R V I N G

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C E L E S T I A L O B S E R V I N G

C E L E S T I A L O B S E R V I N G

With your telescope set up, you are ready to use it for celestial observing. This section covers visual observing of both solar system and deep-sky objects.

Observing the Moon

In the night sky, the Moon is a prime target for your first look because it is extremely bright and easy to find. Often, it is a temptation to look at the Moon when it is full. At this time, the face we see is fully illuminated and its light can be overpowering. In addition, little or no contrast can be seen during this phase.

One of the best times to observe the Moon is during its partial phases (around the time of first or third quarter). Long shadows reveal a great amount of detail on the lunar surface. At low power you will be able to see most of the lunar disk at one time. Change to higher power (magnifi- cation) to focus in on a smaller area. Keep in mind that if you are not using an optional motor drive, the rotation of the Earth will cause the Moon to drift out of your field of view. You will have to manually adjust

	the telescope to keep the Moon centered. This 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.


Observing the	Other easy targets in the night sky include the five naked eye planets. You
Planets	can see Venus go through its lunar-like phases. Mars can reveal a host of
	surface detail and one, if not both, of its polar caps. You will be able to see
	the cloud belts of Jupiter and the great Red Spot (if it is visible at the time you
	are observing). In addition, you will also be able to see the moons of Jupiter as
	they orbit this gas giant. Saturn with its beautiful ring system and Cassini's
	division are easily visible at moderate power. All you need to know is where to
	look. Most astronomy publications tell where the planets can be found in the
	sky each month.

36 • Celestial Observing

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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 Using the Lens Cap Aperture Stop Table of ContentsI N T R O D U C T I O N 4 IntroductionHow to Use This Manual AWordofCaution IntroductionThe Refractor Optical System The Mount6 Introduction A S S E M B L I N G Y O U R C R - 1 5 0 H D Unpacking Your CR-150HDThe CR-150HD Setting Up the Tripod Adjusting the Tripod Height Assembling the CG-5Equatorial MountTripod Head Attaching the Accessory Tray 10 The CR-150HDAttaching the Equatorial Mount Attaching the R.A. Slow Motion Knob 12 The CR-150HDAttaching the Declination Slow Motion Knob 1.Lock the DEC clamp to hold the mount in place 14 The CR-150HDAttaching the Telescope to the Mount Tube Rings Dovetail BracketBalancing the Telescope in R.A 16 The CR-150HDBalancing the Telescope in DEC COMPLETELYAdjusting the Mount in Altitude Adjusting the Mount in Azimuth18 The CR-150HD Technical Specifications Disassembling and Transporting Your CR 150 HDStoring Your CR- 150 HD OPTICAL TUBEAttaching the Accessories T E L E S C O P E B A S I C SThe Star Diagonal The Eyepiece1 1/4 Accessory Focuser TensionAdapter Built-inT-AdapterFocusing Attaching the Finder22 Telescope Basics Aligning the Finder Image Orientation YourFirstLookDaytimeObserving NEVER POINT YOUR TELESCOPE AT THE SUN UNLESSNighttime 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 Motion of the Stars Astronomy BasicsPolar Alignment EquatorDefinition 30 Astronomy BasicsFinding the Pole Latitude Scales 32 Astronomy BasicsPointingatPolaris DeclinationDrift 34 Astronomy BasicsAligning the R.A Setting Circle Polar Alignment FindersObserving the Moon Observing thePlanets C E L E S T I A L O B S E R V I N GUsing the Lens Cap Aperture Stop Observing the SunSOLAROBSERVINGHINTS Celestial ObservingUsing the Setting Circles Observing Deep-SkyObjects38 Celestial Observing StarHopping 40 Celestial Observing Viewing Conditions TransparencySky Illumination Seeing42 Celestial Observing C E L E S T I A L P H O T O G R A P H Y Celestial PhotographyShort Exposure Prime Focus Lunar PhaseCrescent QuarterThe 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 Piggyback 46 Celestial PhotographyEktar 1000 color print Konica 3200 color print Projection Photography 48 Celestial 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 50 Optional Accessories O P T I O N A L A C C E S S O R I E SDual Axis Drive System - #93523 Super Modified Achromatic SMA EyepiecesOptional Accessories 52 Optional Accessories Motor Drive System - #93518THEMESSIERCATALOG NGC#Const Type54 The Messier Catalog NGC# LIST OF BRIGHT STARS EpochStar Name ConstellationFOR FURTHER READING Astronomy TextsAtlases General Observational AstronomyCELESTRON ONE YEAR WARRANTY Celestron International 2835 Columbia Street Torrance, CA Tel FaxItem #21017-INST Price $10.00