Aligning the Finder Scope:
Thelowpowerandwideeldofviewprovidedbythe6x30mmnderscope
(Fig.1-5)providesaquickandeasywaytosightanobjectpriortolooking
throughthehigh-powertelescope.Thenderscopemustrstbeproperly
alignedwiththetelescopeinordertoworkproperly.Thisalignmentisbest
performedduringthedaylight.Followthestepsbelowtoalignyournder
scope properly:
• PlacetheKellner 20mmeyepiece(Fig.2-14)intothecornerlens
(Fig. 2-15)ofthetelescope.
• LoosenboththeR.A.lockknob(Fig.3-22)andtheDec.lockknob
(Fig.3-24)sothatthetelescopeswingsfreelyalongbothaxes.
• Pointthemaintelescopeataspecificlandobject200yardsormore
away.LockdowntheR.A.andDec.axes.Turntheslowmotion
cables(Fig.2–8,17)untiltheobjectiscenteredinthetelescope
field.
• Nowlookthroughthefinderscope(Fig.1-5)andloosenortighten
thefinderscopebracketscrews(Fig.4-26)untilthecrosshairsare
centeredonthesameobject.Focusbyturningthefinderscopefo-
cusknob(Fig.4-27)untiltheimageinthefinderscopeissharpand
clear.
• Checkthealignmentatnighttimebyrepeatingthisprocesswitha
brightstarorthemoon.Makeanynecessaryadjustments.
Nowthatyournderscopeisproperlyaligned,anyobjectcenteredinyour
nderscopeshouldalsobecenteredinyourtelescope.
Calculating Power:
Themagnicationofatelescopedependsonboththefocallengthofyour
telescope as well as the eyepiece you use. There is a simple formula you can
usetodeterminethemagnicationyouareusingatanygiventime.Simply
dividethefocallengthofthetelescopebythefocallengthoftheeyepiece.
For example, if you are using the 20mm eyepiece with your RP-400
telescope thepowerwouldbe:
Power = 1000mm / 20mm = 50x
Usinganeyepiecewithasmallerfocallengthwillincreasethemagnication
ofyourtelescope.Itisalwaysbesttostartatthelowestmagnicationcon-
guration.Thewidereldofviewmakesiteasiertospotfarawayobjects.
Onceanobjectiscenteredinyoureldofviewyoucanswitchtothehigher
powercongurations.
UnderstandingCelestialMovement:
Inordertogetthemostenjoymentoutofyourtelescopeitisnecessaryto
knowthebasicsofhowcelestialobjectsmoveacrossthesky.Duetothero-
tationoftheearth,celestialobjectsappeartomovefromEasttoWestacross
thesky,muchliketheSun.Youwillnoticethismovementasanobjectin
yourtelescopeeldofviewwillslowlymoveacrosstheeldandoutof
view.Continuousadjustmentisneededtokeepanobjectintheeldofview.
Thiswillbeexplainedinmoredetaillater.
Manypeoplechooseto“star-hop”whenusingatelescope,aquickandrela-
tivelyeasywaytostart.Thisisamethodofusingeasilyidentiablestars
andconstellationstoserveasreferencepointstondotherobjectsinthesky.
Amoreadvancedandprecisemethodoflocatingspeciccelestialobjectsis
byusingsettingcircles(Fig.3-20,21)locatedonyourequatorialmount(Fig.
1-7)tondthecelestialcoordinatesofthatparticularobject.
ABriefOverviewofCelestialCoordinates:
Astronomersuseasystemof“celestialcoordinates”similartotheEarth’s
latitudeandlongitudesystemtohelplocateobjectsinthesky.Allcelestial
objectsaremappedona“celestialsphere”,animaginarysphereofarbitrary
sizeconcentricwiththeEarth.IfyouextendtheEarth’srotationalaxisto
innity,bothNorthandSouth,thepointsatwhichthisaxisintersectsthe
celestialsphereareknownastheNorthCelestialPoleandtheSouthCelestial
Pole.IfyouprojecttheEarth’sequatoroutwardtothecelestialspherethis
wouldbeknownasthe“CelestialEquator”.
Theequivalenttolatitudelinesonthecelestialsphereareknownaslinesof
“Declination”,or“Dec.”forshort.Theselinesaremeasuredindegrees,min-
utesandseconds.Declinationreadingsnorthofthecelestialequatorcarrya
“+”sign,whilereadingssouthofthecelestialequatorcarrya“-“sign.Ob-
jectslocatedonthecelestialequatorhavea0°0’0”Declination.TheNorth
CelestialPolehasa+90°0’0”DeclinationwhiletheSouthCelestialPolehas
a-90°0’0”Declination.ThestarPolarisislocatedveryneartheNorthCeles-
tialPoleandhasa+89.2°Declination.
Theequivalenttolongitudelinesonthecelestialsphereareknownaslinesof
“RightAscension”or“R.A.”forshort.Theselinesaremeasuredinhours,minutes
andsecondsstartingatthe“zero”lineofR.A.whichpassesthroughtheconstella-
tionPegasus.Thereare24primarylinesofR.A.locatedat15°intervalsalongthe
celestialequator.RightAscensioncoordinatesrangefrom0hr0min0secto(but
notincluding)24hr0min0sec.
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