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Celestron OMNI XLT 102 manual

Models: OMNI XLT 102

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R -
Reflector	A telescope in which the light is collected by means of a mirror.
Resolution	The minimum detectable angle an optical system can detect. Because of diffraction, there is a limit
	to the minimum angle, resolution. The larger the aperture, the better the resolution.
Right Ascension: (RA)	The angular distance of a celestial object measured in hours, minutes, and seconds along the
	Celestial Equator eastward from the Vernal Equinox.
S -
Schmidt Telescope	Rated the most important advance in optics in 200 years, the Schmidt telescope combines the best
	features of the refractor and reflector for photographic purposes. It was invented in 1930 by
	Bernhard Voldemar Schmidt (1879-1935).
Sidereal Rate	This is the angular speed at which the Earth is rotating. Telescope tracking motors drive the
	telescope at this rate. The rate is 15 arc seconds per second or 15 degrees per hour.
T -
Terminator	The boundary line between the light and dark portion of the moon or a planet.
U -
Universe	The totality of astronomical things, events, relations and energies capable of being described
	objectively.
V -
Variable Star	A star whose brightness varies over time due to either inherent properties of the star or something
	eclipsing or obscuring the brightness of the star.
W -
Waning Moon	The period of the moon's cycle between full and new, when its illuminated portion is decreasing.
Waxing Moon	The period of the moon's cycle between new and full, when its illuminated portion is increasing.
Z -

Zenith	The point on the Celestial Sphere directly above the observer.
Zodiac	The zodiac is the portion of the Celestial Sphere that lies within 8 degrees on either side of the
	Ecliptic. The apparent paths of the Sun, the Moon, and the planets, with the exception of some
	portions of the path of Pluto, lie within this band. Twelve divisions, or signs, each 30 degrees in
	width, comprise the zodiac. These signs coincided with the zodiacal constellations about 2,000 years
	ago. Because of the Precession of the Earth's axis, the Vernal Equinox has moved westward by
	about 30 degrees since that time; the signs have moved with it and thus no longer coincide with the
	constellations.

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Celestron OMNI XLT 102 manual

Contents

Omni XLT Omni XLT Series TelescopesINSTRUCTION MANUAL Omni XLT 102EDTable of Contents Transparency proper solar filter. Permanent and irreversible eye damage may result Counterweight Bar Accessory Tray/ Leg BraceCounterweights Latitude Adjustment ScrewFocuser Figure 1-2 Omni XLT 150 NewtonianFinderscope Bracket Accessory Tray/ Leg BraceLatitude Scale Declination Setting CircleFigure 1-3 Omni XLT 127 Schmidt-Cassegrain Schmidt Corrector LensSetting up the Tripod Attaching the Equatorial Mount Installing the Counterweight Bar Attaching the Center Leg BraceInstalling the Counterweights Attaching the Slow Motion Control Knobs CablesAttaching the Telescope Tube to the Mount Tube Rings Mounting Bracket Mounting Platform Telescope MountingScrew Installing the Finderscope Installing the Visual Backmake contact with the finderscope body Installing the Star Diagonal Installing the EyepiecesMoving the Telescope Manually Balancing the Mount in R.ADEC Clamp R.A. Clamp Adjusting the Mount Balancing the Mount in DECGO OF THE TELESCOPE TUBE COMPLETELY Adjusting the Mount in Altitude Adjusting the Mount in AzimuthA cutaway view of the light path of the Refractor optical design A cutaway view of the light path of the Newtonian optical design Actual image orientation as seen with the unaided eye FocusingImage Orientation Reversed from left to right, asAligning the Finderscope Calculating MagnificationDetermining Field of View General Observing HintsThe Celestial Coordinate System The celestial sphere seen from the outside showing R.A. and DECMotion of the Stars Starts seen near the north celestial poleStarts seen near the celestial equator Latitude Scale Pointing at PolarisFinding the North Celestial Pole Big Dipper Polar Alignment in the Southern HemispherePolar Alignment with the Latitude Scale Litle DipperPointing at Sigma Octantis Finding the South Celestial Pole SCPDeclination Drift Method of Polar Alignment Aligning the R.A. Setting Circle Using the R.A. Vernier Scale Observing the Planets Observing the MoonLunar Observing Hints Planetary Observing HintsObserving Deep Sky Objects Observing the SunSolar Observing Hints Seeing ConditionsUsing the Lens Cap Aperture Stop with Refractor Telescopes SeeingPiggyback Photography Short Exposure Prime Focus Photography for Schmidt-Cassegrains Using Digital CamerasShort Exposure Prime Focus Photography for Refractors & Newtonians See note about digital cameras belowEyepiece Projection for a Schmidt-Cassegrain Long Exposure Prime Focus Photography Planetary and Lunar Photography with Special Imagers Metering CCD Imaging for Deep Sky ObjectsTerrestrial Photography Reducing VibrationCare and Cleaning of the Optics Collimation of Refractorsrub in circles Collimation of a Schmidt-Cassegrain two 2 turnsTo make collimation a simple procedure, follow these easy steps Collimation of a Newtonian Aligning the Secondary MirrorAligning the Primary Mirror Both mirrors aligned with the collimating cap in the focuser Primary mirror needs Secondary mirror needsadjustment adjustmentSecondary Mirror PrimaryProcedure -- Please read this section completely before beginning Night Time Star Collimatingappear patterndiffraction Series 3 - # Series 1 - #Series 2 - # Series 4 - #Page Page Appendix A Technical Specifications Appendix B - Glossary of Terms Page Page Page Page Page Page Page Page Celestron Two Year Warranty Products or instructions may change without notice or obligation Celestron 2835 Columbia Street Torrance, CA 90503 U.S.A. Tel. 310Copyright 2008 Celestron All rights reserved Item # 21088-INST Rev Printed in China $10.00