A computerised GoTo telescope, a Celestron NexStar SE being the classic example, is a lovely thing to own. You type in what you want to see, the motors whir, and the telescope points itself straight at it. Thousands of objects, found for you, at the press of a button. When it works, it feels like magic.
The catch is that it only works once you have taught it where it is and which way it is facing, a one-time routine each night called star alignment. Get that right and the rest of the evening is effortless. Get it wrong, and the scope will slew confidently to completely the wrong patch of sky, which is exactly where a lot of new GoTo owners give up. So this guide spends its energy where it counts: getting your setup solid and walking you through the NexStar alignment cleanly, so night one ends with the Moon in your eyepiece rather than the handset in a drawer.
What is in the box, and what everything is called
Lay it all out in good light. Here is the tour.
The optical tube on a NexStar SE is a compact compound telescope, either a Maksutov-Cassegrain (the 4SE) or a Schmidt-Cassegrain (the 5SE, 6SE, and 8SE). It folds a long light path into a short, stubby tube, and you look into an eyepiece at the back, through a star diagonal.
The single-arm fork mount is the motorized arm the tube sits in, and it holds the electronics that do the pointing. Plugged into it is the hand controller (Celestron calls it NexStar+), the keypad with a screen that you use to align the scope and then command it. The tripod is usually steel, with a central leg spreader that doubles as an accessory tray.
You will have a star diagonal that slots into the back of the tube, at least one eyepiece (typically a 25mm, where the bigger number means lower power and a wider view), and a red-dot finder (Celestron’s StarPointer) on the tube, which you will need for the alignment. Finally, there is a battery compartment that takes eight AA batteries, and I want to flag right now that batteries alone will let you down. More on that shortly, because it is the number one cause of GoTo misery.
Setting it up, in order
Spread the tripod and get it roughly level. Open the legs on firm ground, fit the leg spreader, and use the built-in bubble level (or a phone app) to get the top roughly level. GoTo mounts point more accurately from a level start, so this small step pays off.
Fit the mount and tube. On a NexStar SE the fork arm mounts onto the tripod, and the tube is usually already attached to the arm. Seat it, tighten the clamps, and make sure nothing is loose.
Sort out power before anything else. This is the step that quietly ruins more first nights than any other, so treat it as essential, not optional. Eight AA batteries drive the motors for barely an hour, and as they fade the mount starts to slew erratically, lose alignment, and point badly, which feels exactly like the telescope being broken when it is really just hungry. Do yourself an enormous favor and power it from a mains AC adapter or a rechargeable power tank instead. It is the best money you will spend on the scope, and I will come back to it at the end.
Fit the diagonal and your lowest-power eyepiece. Slot the star diagonal into the back of the tube, then drop your lowest-power eyepiece, the 25mm, into the diagonal and secure it. Start low, always: a wide view makes both the alignment stars and your targets far easier to center.
Align the red-dot finder in daylight. Even though the mount will do the finding once aligned, you rely on that finder to center the alignment stars accurately, so it must point where the main tube points. Do this in daylight on a distant landmark, never the Sun, which causes instant permanent eye damage. Center a far-off chimney or pylon in the eyepiece, then adjust the finder to sit on it. The full method is in how to align a finderscope. Get it done before dark.
The NexStar alignment, step by step
This is the part unique to a GoTo scope, and it is the one that matters most. Done carefully, it takes five minutes and unlocks the whole sky. Here is the clean version.
Power on and enter the details. Switch on and the handset wakes up. It will ask you to confirm or enter the date, time, time zone, and location. Take real care here, because a wrong time, the wrong daylight-saving setting, or a mistyped location throws the pointing off across the whole sky. Enter your city or your latitude and longitude, set the time to the minute, and double-check whether daylight saving should be on.
Choose an alignment method. The NexStar offers a few. The friendliest for a beginner is SkyAlign, because it does not require you to know the names of any stars. You simply point the scope at any three bright objects in turn, and the computer works out which they are.
Center three bright objects. Using the arrow buttons on the handset, slew the telescope to the first bright star or planet, get it roughly into the finder, then look through the low-power eyepiece and center it precisely before pressing Align. Repeat for a second and a third bright object, choosing ones that are well spread apart across the sky rather than bunched together. Try to avoid two that sit close to each other, and be aware that a very bright “star” might actually be a planet, which is fine for SkyAlign as long as it is genuinely bright and you spread your choices out.
Center precisely, every time. The accuracy of your entire night rests on how well you center those three objects, so slow down for this. Make your final approach to center using the up and right buttons (this takes the slack out of the gears and improves pointing), and get each object dead in the middle of the eyepiece before confirming.
Alignment success. When the handset says alignment is complete, the mount now knows where everything is. Press the object menu, pick the Moon or a planet, press Enter, and watch the scope slew itself straight to it. That first automatic slew, ending with the target sitting in your eyepiece, is a genuinely satisfying moment.
Your first night: a guaranteed win in 15 minutes
Your target is the Moon, and with the alignment done it is almost too easy. Give the compound tube a good while to cool first, 45 minutes to an hour, because these sealed tubes hold heat and the view sharpens up noticeably once settled, especially on the Moon and planets.
Check the Tonight’s Sky tool to confirm the Moon is up. Then, on the handset, go to the object list, select the Moon, and press Enter. The scope slews itself there and, because you aligned carefully, the Moon should be sitting in or very near the center of your low-power eyepiece. Focus slowly until the craters snap sharp, and enjoy. Explore the terminator, the line between light and dark, where the shadows are longest and the surface looks most three-dimensional.
And if the alignment did not quite land the Moon in view? Do not panic, and do not assume the scope is broken. Use the handset arrows to nudge it into the eyepiece, then carry on. You can also skip the computer entirely on a first night: point the scope at the Moon by hand using the finder, and enjoy the view while you build up to trusting the alignment. The telescope works beautifully either way.
The five mistakes that stop people seeing anything
Nearly every GoTo frustration comes down to one of these five.
- Weak or dying power. This is the big one. Flat or fading AA batteries make the mount slew erratically and lose its alignment, and it mimics a fault perfectly. Run it from an AC adapter or a power tank and a whole category of problems disappears.
- Wrong time, date, or location. The computer points using the numbers you give it. A mistyped location, the wrong time zone, or daylight saving set incorrectly will send every slew to the wrong place. Enter these carefully and precisely.
- The finder is not aligned. You need the finder to center the alignment stars, and if it points off from the main tube, your alignment will be sloppy and so will everything after it. Align it in daylight first.
- Careless or bunched alignment stars. Rushing the centering, or picking three objects close together, gives the computer a poor fix and inaccurate pointing all night. Center each one precisely, finishing with the up and right buttons, and spread your three choices across the sky.
- Too much magnification, too soon. Swapping to a high-power eyepiece before you have the object centered makes both alignment and finding much harder. Do everything on the low-power 25mm first, then zoom in once the target is framed.
What to look at next
With the alignment mastered, your GoTo scope will happily find far more than you will get through in a night, and the question becomes which of it is worth your time. The Tonight’s Sky tool answers exactly that: tell it your location and equipment, and it gives you a personalized list of the best objects visible from your backyard right now, in a sensible order, with a finder chart for each. Line those up on the handset and you have a ready-made tour.
To understand what you are looking at rather than just letting the motors do the work, how to read a star chart is well worth your time, and when you want sharper views of the planets, what eyepieces do I need for my telescope will point you the right way.
The one accessory I would call close to essential here is a mains AC adapter or a rechargeable power tank, because reliable power transforms how a GoTo scope behaves. Add a red flashlight to protect your night vision while you read the handset, and you are properly set up.
Do not let the technology intimidate you. Run the alignment carefully a couple of times and it becomes a quick, familiar ritual, after which the entire sky is a button-press away.
Related setup guides
- How to set up a tabletop Dobsonian
- How to set up a refractor telescope
- How to set up a reflector on an equatorial mount
