Celestron NexStar 80GTL manual

I I N N S S T T R R U U C C T T I I O O N N M M A A N N U U A A L L N N e e x x S S t t a a r r 8 8 0 0 G G T T L L[...]

2 T T A A B B L L E E O O F F C C O O N N T T E E N N T T S S INTRODUCTION ............................................................................................................................................................. 4 W W a a r r n n i i n n g g .......................................................................................[...]

3 Observing the Sun .............................................................................................................. ................................... 24 Solar Observ ing Hints .......................................................................................................... ................................. 25 Observing Dee[...]

4 Congratula tions on y our purcha se of the Celes tron Nex Star! T he Ne xStar ushe rs in a w hole new g enera tion of compute r automa ted technolog y . Simple and f riendly to use , the Ne xStar is up a nd runn ing af ter loca ting just tw o alig nment sta rs. It’s the perf ect combination of pow er and por tability . If y ou are ne w to as tr[...]

5 1 Objective Lens 7 Focuser Knob 2 Fork Arm 8 Erect Image Diag onal - 90˚ 3 Power Outlet 9 Eyepiece 4 Tripod 10 Star Pointer F inderscope 5 Hand C ontrol 11 Optical Tu be 6 Accessory Tray w/ hand contr ol holder 12 Tube Ring Clam p The NexStar 80GT L Refractor Te lesc ope 10 1 2 9 8 6 3 4 7 11 5 12[...]

6 The Nex Star comes partially assemble d and can be operati onal in a ma tter of minutes. T he NexSta r is conveniently pac kaged in one reu sable shipping carton that contain s the following accessorie s: NexStar 80 GTL 25mm & 10mm Ey epiece s – 1¼" 1¼" E rect Image Diagonal Star Pointer Fi ndersc ope and Mounting Bracket Deluxe[...]

7 3. From underneath the tripod s upport brace, thread the locking bo lt into the hole in the center of the accessory tray. Do not over tighte n. The accessor y tray has a built-on han d control holder protrudin g from the side. The ba ck of the hand contro l has an ope ning that s lides ov er the c lip on the inside of the ho lder. It is a good id[...]

8 T T h h e e E E y y e e p p i i e e c c e e The eyepi ece, is th e optical el ement th at magnifies th e image focused b y the telesco pe. The e yepiece fits either di rectly into the focuser or i nto the diagon al. To install th e ey epiece: 1. L oosen the thumbs crew on the dia gonal s o it does not obstruct the in ner diam eter of the barrel. [...]

9 not dam age the glass w indow or y our ey e. The Sta r Pointer co mes e quipped with a varia ble brig htness c ontrol, tw o axe s alignme nt control a nd m ounting brack ets. Before the Star Pointer is ready to be used, it m ust be attac hed to t he telesc ope tub e and pr operly alig ned: S S t t a a r r P P o o i i n n t t e e r r I I n n s s t[...]

10 U U s s i i n n g g y y o o u u r r S S o o l l a a r r F F i i l l t t e e r r Solar ob serving is one o f the most rewarding for m s of celest ial observati ons. Yet, becau se the Sun is so b right, special precaut ions must be taken to ensure your safet y and p rotect your equ ipment. Therefore, rea d these instructio ns through complete ly B[...]

11 A A t t t t a a c c h h i i n n g g t t h h e e H H a a n n d d C C o o n n t t r r o o l l The Ne xStar GT hand control has a phone jack type connector a t th e end of its cord. Plug t he phone jac k connec tor into t he outl et at the base of the telescope’s fork arm. Push the connecto r int o the outlet until it clicks into place and place [...]

12 Planets - A ll 8 planets in our S olar Sy stem plus the Mo on. Stars – A compiled list of the b ri ghtest st ars from the SAO catalo g. List – For quick access, all of the b est and most po pular objects in the NexS tar database h ave been broken down into lists ba sed on their type and/or comm on nam e: Named Stars Common na me listing of t[...]

13 10. Scroll K eys: Used to sc roll up a nd dow n within a ny of the m enu lists. A double arrow sy mbol on the rig ht side of the LCD indicates that the scro ll keys can be used to view additional information. 11. Rate: Instant ly changes the rate of speed of the moto rs when the directio n buttons are pressed . 12. RS-232 J ack : Allows use with[...]

14 Y Use the Up an d Down scroll keys to choo se between City Database and Cust om Site . City Data base will allow you to select the c losest city to your observing site from a list of eithe r international or U.S. locatio n. Custom Site allows you to enter t he exa ct longitu de and la titude of y our obser ving site . Sele ct City Databa se and [...]

15 1. Once the NexS tar is powered on, use th e Up and Down scroll keys to select Two Two Two Two- - - -Star Al ign Star Align Star Align Star Align , and pr ess ENTER. 2. The Nex Star display w ill ask y ou to m o ve the telescope tube until it is horiz ontal t o the groun d. To do t his, use the direction k eys (3) to m ove the telescope unti l i[...]

16 Object Catalog S S e e l l e e c c t t i i n n g g a a n n O O b b j j e e c c t t Now tha t the tele scope is prope rly a ligned, y ou can choos e an obj ect fr om any of the catalog s in the Nex Star's data base . The hand con trol has a key designated for each of the cat alogs in its database. There are two ways to sel ect objects fro m [...]

17 • To slew to the object display ed, pr ess ENT ER. • To see the n ext tour obj ect, press the Do wn key. Directi on Buttons The Nex Star has four direc tion buttons in t he center of the hand control w hich co ntrols the tele scope m otion in altitu de (up an d down) and azimuth (left and right). The telescop e can be cont rolled at nine dif[...]

18 Alt-Az This is the def ault trac king rate and is use d when t he telescope has be en properly alig ned. EQ North Used to track the sky when the tele scope is polar a ligned using an equatorial w edg e in the N orthern Hemis phere. EQ S outh Used to track the sky when the tele scope is pola r aligned using an equatorial w edg e in the Souther n [...]

19 object s are relative to th e location of th e telescope, they are o nly valid for t hat exact locat ion. To save land objects, once again center th e desired ob ject in th e eyepiece. Scroll d own to the " Save Land Obj " comm and and pr ess ENTER. The display will ask y ou to enter a num ber betw een 1-2 5 to ide ntify the object. Pr[...]

20 Slew Li mits – Se ts the lim its in altitude that the te lescope c an slew w ithout display ing a warning message first. T he NexStar hand con trol w ill w arn y ou before a llowing the telesc ope tu be to s lew to an obje ct be low the hor izon or slew to a n objec t that is high en ough tha t the tube m ight hit one of the tr ipod le gs. H o[...]

21 ALT- AZ E Q NO RTH EQ SOUT H OF F MO D E SIDEREAL SOLAR LUN AR RA TE T RA CKING V IEW T IM E-SIT E SIDERE A L T IM E ALTMAX I N LI ST A L T M IN IN L IS T FILTER LIM IT S SET UP T IME/ SIT E ANT I- BACKLASH SLEW LIM IT S DIRECT ION BUT T O NS LIG HT CONT ROL SELEC T MODEL UT ILITIES RS- 232 GOTO SKY OBJ SAVE SKY OBJ ENT ER R A & DEC GOT O LA[...]

22 Correct i mage as view ed w hen using er ect image diag onal Inverted i m age, a s viewed w ith the eyepiece directly in telescop e A telescope is an instrume nt that collects a nd focuses lig ht. The nature of the optic al design de term ines how the light is f oc use d. Some telescope s, know n as ref ractors, use lenses . Other tele scopes , [...]

23 D D e e t t e e r r m m i i n n i i n n g g F F i i e e l l d d o o f f V V i i e e w w Determining the f ield of v iew is important if you want to g et an idea of the ang ular size of the ob ject y ou are observ ing. T o calculat e the actual fiel d of view, divid e the apparent field of the eyepiece (s up plied by the eyep iece manufactur er) [...]

24 With y our teles cope set up, y ou are rea dy to use it f or obse rving. T his se ction cov ers vis ual observ ing hints for bot h solar sy stem and deep sky objects a s we ll as general obse rving con ditions which w ill aff ect your a bility to observ e. O O b b s s e e r r v v i i n n g g t t h h e e M M o o o o n n Often, it is te mpting to [...]

25 •S uns pot s : Dark regions of the sun' s phot osphere w h ich a re co oler than the surrou nding area . Sunspots are usua lly seen to co nsist of two pa rts: the in ner dark er core, the um bra, and t he surrou nding le ss dark region, t he penum bra. •Granulation : S mall convectio n cells in the photosph ere that appear as "rice[...]

26 object s. Aerosols ejected i nto the upper atmosphere fro m volcanic erup tions also affect transp arency. Ideal conditions are when th e night sky is in ky black. S S k k y y I I l l l l u u m m i i n n a a t t i i o o n n Gene ral sky brightening c aused b y the Moon, aurorae , natura l airgl ow, and lig ht po llution g reatly affec t transpar[...]

27 While your Ne xStar tele scope require s little m aintenance , there are a f ew things to re mem ber that will ensure y our telescope perform s at its be st. Care and Cleanin g of the Optics Occasionally, dust and /or m oisture may build up on the le ns of your telescope. Speci al care shoul d be taken w hen cleaning an y instrume nt so as not t[...]

28 You will find that add itional accessories enhance y our viewing pleasu re and expand the u sefulness of your telescope. For ease of reference, all the accessor ies are listed i n alphabetical order. Adapter, A C (# 18773) – A llows DC (battery ) powe red telescope s to be co nverte d for use w ith 120 v olt AC power. T he adapter attac hes to[...]

29 Filter, Light Pollution Redu ction –LPR (#94126A) - The se filte rs are designed to enha nce y our views of deep sky astronom ical obje cts w hen view ed from urban area s. LPR Filters s electiv ely reduce the transm ission of certain w avele ngths of lig ht, specif ically those pr odu ced by artif icial lights . This inc ludes m ercury and hi[...]

30 A PPENDI X A - TECHNIC A L SPECIFIC A TIONS O O O p p p t t t i i i c c c a a a l l l S S S p p p e e e c c c i i i f f f i i i c c c a a a t t t i i i o o o n n n NexStar 80GTL Design Refractor Ape rtur e 80m m Fo cal L eng th 900mm F/rati o of the Op tical System F/11 Obj ective Coat ings Fully Coa ted Highe st Use ful Mag nific ation 189x Low[...]

31 GLOSSARY OF TERMS A - Absolute magnitude The a pparent m agnitude tha t a sta r w ould hav e if it w ere obse rved from a sta ndard distanc e of 10 parsec s, or 32.6 lig ht-ye ars. The a bsolute m agnitude of the Su n is 4. 8. at a distance of 10 parsecs , it would just be visible on Earth on a clear moonless nig ht away from surface light. Airy[...]

32 J - Jovian P lanets Any of the four gas giant plan ets that are at a greater di stance form the su n than the terrest rial planet s. K - Kuiper Belt A reg ion bey ond the or bit of Neptune extendi ng to a bout 100 0 AU w hich is a source of m any short period com ets. L - Light-Year (l y) A light- y ear is th e distance l ight traverses in a vac[...]

33 Term inator The bou ndary line betw een the li ght and dark por tion of the m oon or a pla net. U - Univers e The totality of astronom ical things , events , relations an d energ ies ca pable of be ing desc ribed object ively. V - Variab le Star A star whose br ightness varies over ti me due to either in herent properties o f the star or somethi[...]

34 Appendix C - RS-232 Connection You can co ntrol y our Nex Star tele scope w ith a com puter via the PC port on t he hand co ntrol and using an optiona l RS- 232 cabl e (see Optional Accessor ies section of manual). Once co nnected, th e NexStar can be con trolled using pop ular astronomy software program s. C C o o m m m m u u n n i i c c a a t [...]

35 A PPENDIX D – MA PS OF TIME ZONES[...]

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CELESTRON TWO YEAR WARRANTY A. Celestron warran ts this telescope t o be free from defects in mat erials and workmanship for two years. Celestron will repai r or replac e such produc t or part thereof which, upon inspec tion by Celest ron, is found to be defec tive in materials or workma nship. As a condition to the obli gation of Celestron t o rep[...]

Celest ron 2835 C olumbia Stre et Torra nce, CA 90503 Tel. ( 310) 3 28-9560 Fax. ( 310) 212 -5835 Web site a t http//www .celestron.c om Copy right 20 04 Celes tron All rights reserved. (Products or instr uctions m ay change without notice or obligation.) This devic e complies w ith Part 15 of the FCC R ule. Opera tion is subje ct to the f ollowing[...]