User manual CELESTRON S-55F

[. . . ] 8 Powering the NexStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 The Hand Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 The Eyepiece. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 The Star Pointer Finderscope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Once the correct NexStar model has been selected the power needs to be restarted before beginning the alignment procedure. The Select Model feature will return the hand control to its original factory settings. Parameters such as backlash compensation values along with slew and filter limits will be reset. However, stored parameters such as user defined objects will remain saved even after the model has been changed. RS-232 - The NexStar has a RS-232 port located on the bottom of the hand control that allows it to communicate with many astronomy computer programs such as The Sky by Software Bisque. Before attempting to create a link with a computer, select the RS-232 option and press Enter. 20 N S eady ex tarR M ENU T R ACK IN G M ODE A L T -A Z EQ NO RTH E Q S O UTH OFF R AT E S ID E R E A L SOLAR LUNAR V IE W T IM E -S IT E S IDE R E AL T IM E FILT E R LIM IT S A L T M A X IN L IS T A L T M IN IN L IS T U T ILIT IE S S E TU P TIM E /S ITE A N TI-B A C K L A S H S L E W L IM ITS D IR E C TIO N B U TTO N S L IG H T C O N TR O L SELECT MODEL R S -2 3 2 U S E R OBJE C T S G O TO S K Y O B J SAVE SKY OBJ E NTE R RA & DE C G O TO LA ND O B J SAVE LAND OBJ G E T ALT -AZ G OT O ALT -AZ G E T R A-D E C G OT O R A-D E C A L IG NM ENT AU T O ALIG N P O IN T T U B E N O R T H & L E V E L CIT Y DAT ABASE Un ited States Ch oose State Ch oose City E n ter Tim e E n ter Date L IST NA M E D S TA R N A M E D O B JE C T A S T E R IS M S TOUR V A R IA B L E S T A R DO UBLE S TA R CALDW ELL M E S S IE R NGC S O LA R S Y S TE M SAO In te rn a tio n a l Ch oose Cou n try Ch oose City CUS T O M S IT E En ter Lon g /Lat E n ter Tim e E n ter Date T W O-S T AR ALIG NM E NT LEVEL TUBE SELECT STAR 1 CENTER STAR 1 SELECT STAR 2 CENTER STAR 2 QU IC K ALIG N P O IN T T U B E N O R T H & L E V E L SELECT LO CAT IO N ENTER T IM E E N T ER DA T E NexStar Menu Tree: The following figure is a menu tree showing the sub-menus associated with the primary command functions 21 A telescope is an instrument that collects and focuses light. The nature of the optical design determines how the light is focused. Some telescopes, known as refractors, use lenses. Other telescopes, known as reflectors, use mirrors. The Maksutov-Cassegrain optical system uses a combination of mirrors and lenses and is referred to as a compound or catadioptric telescope. This unique design offers large-diameter optics while maintaining very short tube lengths, making them extremely portable. To determine the magnification you simply divide the focal length of your telescope (the NexStar has a focal length of 1300mm) by the focal length of the eyepiece, 25mm. Dividing 1300 by 25 yields a magnification of 52 power. Although the power is variable, each instrument under average skies has a limit to the highest useful magnification. The general rule is that 60 power can be used for every inch of aperture. For example, the NexStar is 4" in diameter. Multiplying 4 by 60 gives a maximum useful magnification of 240 power. Although this is the maximum useful magnification, most observing is done in the range of 20 to 35 power for every inch of aperture which is 80 to 140 times for the NexStar telescope. Determining Field of View Determining the field of view is important if you want to get an idea of the angular size of the object you are observing. To calculate the actual field of view, divide the apparent field of the eyepiece (supplied by the eyepiece manufacturer) by the magnification. In equation format, the formula looks like this: Apparent Field of Eyepiece True Field = Magnification As you can see, before determining the field of view, you must calculate the magnification. Using the example in the previous section, we can determine the field of view using the same 25mm eyepiece. The 25mm eyepiece has an apparent field of view of 52°. [. . . ] 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. 40 Appendix C ­ Maps of Time Zones 41 42 43 44 45 46 47 48 CELESTRON ONE YEAR WARRANTY A. Celestron International (CI) warrants this telescope to be free from defects in materials and workmanship for one year. CI will repair or replace such product or part thereof which, upon inspection by CI, is found to be defective in materials or workmanship. As a condition to the obligation of CI to repair or replace such product, the product must be returned to CI together with proof-of-purchase satisfactory to CI. [. . . ]