GotostarTM Users Manual A quickstart guide to using a Gotostar-equipped EQ5 equatorial mount. In an earlier guide we showed you how to attach the motors, encoders and hand controller to an EQ5type mount and make any necessary adjustments to the gear trains. Even if you have a pre-installed Gotostar system, please ensure that you have read through Install_Gotostar.pdf first. Power Supplies Fig. 1 Initial Setup We also recommend that you familiarise yourself with the operation of your Gotostar in the daytime. For your first trial run you don’t need to install a tube assembly or counterweights — just plug in ... Fig. 2 Polar axis Like any GoTo ‘scope, the motors place high demands on any power supply that you are using when slewing from one part of the sky to another. We recommend that you use the mains transformer provided (with an extension lead and a U.S. to U.K. plug adaptor, if applicable) when using your Gotostar at home. If you are observing away from mains power, we suggest that you use the car cigarette lighter adaptor from your vehicle, or a heavyduty rechargeable 12V power source. A 12V power pack derived from C or D-type alkaline batteries is not suitable and can lead to erratic Gotostar performance. the coiled cables and Gotostar hand control. Fig. 1 shows a view of an Astro-5 German equatorial mount as seen from the north looking down the polar axis (circled in red). The important detail is the position of the chromed declination axis counterweight shaft: it is pointing straight down, in line with the north-facing tripod leg. Slacken the polar axis clamp (arrowed in blue) and rotate the mount about the polar axis until your mount looks the same, then lock the polar axis clamp. This procedure satisfies one condition of the Gotostar Park Position and must be performed every time you setup the mount. Fig. 2 shows the same mount, but seen from the south. In order to satisfy the final condition of the Gotostar Park Position, you’ll need to unlock the declination axis clamp (arrowed black in Figs. 1 & 2) and rotate the mount about the declination axis until the edge of the Vixen-style dovetail bracket (dashed red) lies closely parallel to the polar axis (cyan arrow). The declination axis motor unit (outlined in yellow) must be on the right, or east, side — this is very important! Once your mount looks like Fig. 2, lock the declination axis clamp. First Time Use Now that you know how to position your equatorial mount, this is the time to attach any counterweights followed by the optical tube assembly. (It’s assumed that you have previously determined the balance point of the tube in the Vixen-style dovetail Fig. 3 r, Sta le ole Po ial p the est is, cel lar th Po nor To the & The version number of your software may be slightly different from 070312 ENG, reflecting updates to the built-in software. (The version number is the date in year, TR.A. 13h 6m36s month, day TDEC 90° 0’00” format.) After a R.A. 1h 7m 6s brief pause, the DEC 89°40’55” Lgst 7h16m55s 64X display will revert Alt. 51°21’29” Stop to something like Azi. 0° 0’ 0” 2007-05-23 16:23:40 N that shown left. Don’t worry about what the figures mean at this stage as first you will need to set the Gotostar’s internal clock to the correct date and time. What time is it? Where am I? Unlike most GoTo systems, the Gotostar has a backup battery that remembers this information between sessions. By referring to the red box (How do I navigate my way around the Gotostar menus?) on page 4, ensure that the correct date and time is set for your location — use the left and right arrows to get to the figures you need to change, then type over them using the numeric keys. Just as important is the Daylight Time saving option: use the up or down arrow to change this to a tick or a cross as appropriate. Be sure to press ENTER once you have finished to save the information. bracket and of the counterweight(s) along the shaft. We also assume that you have attempted to point the polar axis of the mount in the close vicinity of Polaris, the Pole Star.) Fig. 3 shows an 80mm Meade triplet refractor in the Park Position as seen from the west with the telescope pointing to the north celestial pole ready to power-up the Gotostar. Before connecting your 12V DC supply, ensure that the grey power switch (see Install_Gotostar.pdf, page two) is in the OFF (button out) position. Check that both the polar axis and declination axis clamps are locked. Press the ON switch, the Gotostar will Ver. 070312 ENG beep, and the power-up splash ©NANJING IDEA SCIENCE screen (right) will & TECHNOLOGY CO. LTD. be displayed. GOTOSTAR Now that it has the correct local date and time, the Gotostar also needs to know where you live in order for it to create a mathematical model of the sky above you. Prior to the next step, obtain your precise latitude and longitude from an Ordnance Survey map, atlas or online gazetteer. Using the Gotostar Menu Tree on page 4, select th e ‘ S etup Set up site info: site ’ o ption then Longitude: th e ‘ S etup lat. & W001d49m35s long.’sub-menu Latitude: (you may also N51d10m44s ‘Select city’, but 000 Min.ahead of UT it’s unlikely that there is one close enough to get accurate results). Above is an example for Stonehenge in Wiltshire, U.K. — 51°10 ’ 4 4 ” N, 1°49’35”W. Always remember to press ENTER after modifying any screen entries to ensure that the new data is saved. Gotostar Alignment Basics Now that Gotostar knows where you live, the date and local time, the hand controller has all the information it needs to locate any of the objects in its vast database. But before it can find anything for you it needs to establish that the Park Position of your mount’s polar axis is indeed pointing at the north celestial pole. Furthermore, every mount’s accuracy of construction varies somewhat, so the optical axis of the telescope may not be perpendicular to the declination axis or, more rarely, the polar axis may not be at right angles to the declination axis. These small errors (known collectively as the cone error) can make a big difference to the GoTo performance of your mount, so it pays to understand the implications. Fortunately, Gotostar version 070312 ENG and later has a ‘ Three star align’ that can largely correct for cone error and is therefore the preferred alignment mode. Know Your Stars! The align process requires you to accurately point the telescope at one, two or three stars (depending on the alignment mode you chose) in turn. Gotostar will choose readily identifiable alignment stars for you by name, since it already knows which ones should be visible from the location and time yo u ’ ve specified. If you don’t already know them, it obviously pays to first learn the Arabic names of the brighter stars from a star atlas or planisphere. Your First Alignment Assuming, then, that you have chosen th e ‘Three star align’ option from th e ‘Align’ menu, Gotostar will ask for confirmation that the mount is in the Park Position before you press ENTER. Gotostar will then present you with the name of a suggested alignment star. If this star is hidden by a tree or building, press the down arrow to advance through the list in alphabetical order until you find a star that is visible. Press ENTER and the mount will spring into life, slewing to where it thinks the star you have selected lies, beeping once it has finished moving. Most likely, the ‘scope won’t be pointing exactly at the star, so use the up, down, left or right arrows to centre the star — first in the finder, then in ... the eyepiece. Once you are done, press ENTER and the next alignment star will be selected. Don’t be surprised if the Gotostar slews the telescope from one side of the mount to the other during this procedure; it is establishing the mount’s cone error by doing so. Repeat this process until you have selected all three stars whereupon Gotostar will compute the polar axis positioning error of your mount and display it. Press BACK and you will return to the display. Select and Slew You will hear that the polar axis motor is now tracking the stars (pressing STOP will arrest the motion, pressing it again will resume tracking) and the altitude (Alt.) and azimuth (Azi.) figures will change as the ‘scope follows an object across the sky. Now that the mount is calibrated and aligned the hard part is over, so you are free to enjoy using the ‘Select and slew’ menu options to find any one of the myriad objects listed in the hand controller’s database. if you find that the GoTo accuracy of your mount is poor for certain areas of the sky, use the ‘Sync. to target ’ o ption on a readily identifiable star in the region before slewing to a fainter target nearby. Tip 2: if you are able to leave the ‘scope setup in an observatory, use th e ‘ Park Scope’ option for a pre-aligned startup next time. Tip 1: Advanced Techniques & Support The Gotostar system is well supported by its Chinese developer, Nanjing IDEA S&T Co. Ltd. This ongoing development ensures that the hand controller’s features and capabilities are continually being updated. Consequently, you are encouraged to visit and join the Gotostar Yahoo Group on the Internet where you will receive help and advice from a dedicated team of enthusiasts devoted to getting the most out of this product. You can find out more at this address: http://tech.groups.yahoo.com/group/ideaxuwen/ Everyone at Astronomica would like to thank you for investing in Gotostar and look forward to hearing of your experiences and observations while using it. Above all, clear skies and enjoy! GotostarTM Menu Tree At-a-glance guide to the menu options available under software Ver. 070312 Eng. Select and slew Planets, sun, Moon Deep sky objects Comets Asteroids Stars Sync. to target Use "Arrow keys" center the object in the telescope's field of view, then press "ENTER". Electronic focuser Focus Set anti-backlash MENU Set up GOTOSTAR Align PEC option Set up Local Time Set up site Set N/S hemisphere Set Display contrast Set eyepiece light Set Backlight Set anti-backlash Set Key Beep Set Mount Type Reset All Upgrade firmware One star align Two star align Three star align Dis R.A. axis error Test anti-backlash PEC play back Record PEC Delete PEC record Set up tracking Sidereal speed Solar speed Lunar speed User defined speed User objects Add a new record Modify records Delete one record Erase all records Auto guide Park Scope To Park Position Manual or Auto guide Guide rate: 1: 1.0X 2: 0.8X 3: 0.6X 4: 0.4X Parks ‘scope then displays Please turn the controller power off. Returns 'scope to Park Position if not already there. By number in catalog By number in catalog Named stars Double stars GCVS variable stars SAO catalog Constellations User objects Enter R.A. DEC. Named deepsky object Messier Catalog NGC IC Catalog UGC Catalog MCG Catalog Caldwell Catalog Abell Catalog Herschel Catalog Mercury Venus Mars Jupiter Saturn Uranus Neptune Pluto Sun Moon Electric focus Speed: 16X Display briefly clears, then returns to menu Enter local date & time + daylight savings Select city Set up lat. & Long. North hemisphere South hemisphere Adjust LCD contrast Adjust on-screen slider R.A. & DEC anti-backlash in 1.5 arcsec steps German equatorials only Displays splash screen and enters upgrade mode LCD Backlight sliders KeyPads Backlight Key Beep ON Key Beep OFF Reset all settings return Start in Park Position, press “ENTER”, then follow instructions Start in Park Position, press “ENTER”, then follow instructions Start in Park Position, press “ENTER”, then follow instructions Displays error of polar axis position in altitude and azimuth Allows you to adjust backlash settings in R.A. and DEC PEC data will be replaced. Continue? PEC play back ON PEC play back OFF Erase PEC data? Enter R.A. and DEC in Epoch J2000 coordinates Select user catalog number and modify accordingly Select user catalog entry by number to delete Erase all records? How do I navigate my way around the Gotostar menus? After the power on message appears, press the button labelled MENU under the screen to access the menu structure depicted above. Use the up (∆ ) and down (V) arrows to move vertically through the list. Selecting an item and pressing ENTER moves you to the right of the diagram; BACK moves you to the left. For example, turn on your Gotostar and press MENU followed by the down arrow three times: this brings you to the ‘Setup GOTOSTAR’ menu. Pressing ENTER at this point takes you to the ‘Setup Local Time’ option; pressing ENTER here enables you to edit the date and time entries.