Finally learning with the Celestron NexStar 8SE
I have a Celestron NexStar 8SE telescope…for those not in the know, that’s an 8″ optical tube on a simple tripod. They call them one-armed bandits (like the slot machines) because there is a single arm that goes from the tripod mount that it rests on up to the tube. Simple, easy to work, but it isn’t very stable, at least not in astronomical viewing terms. It doesn’t allow for much in the way of astro photography due to its limited ability to track the sky over time, thus limiting the photography options of long-exposures. However, there is one feature where the 8SE shines — it’s ease of use.
This was a key ingredient for me in buying a scope, based on knowledge of who I am and the patience I have. If a scope takes 30 minutes to setup, I’m not likely to use it. I need something relatively simple, and the 8SE requires you to basically setup the tripod, attach the scope to the arm, add some power and eyepieces, and you’re good to go. More or less.
The second feature that was a huge selling feature for me is what they call the “go to” feature. You run a simple alignment procedure on the scope, the computer on the mount figures out what stars you are looking at, and after that, it knows where all the other stars and planets should be. So, in theory, you do the alignment, and then after that, you look at a menu, tell it you want to see Saturn, and Bob’s your uncle, the computer will slew your scope around to Saturn. Tell it to show you the Ring Nebula, and bam, there it is.
Except my scope didn’t seem to do that. Sure, it found the moon and planets pretty well, not always dead centre, but certainly within the eyepiece. But beyond that, I have never really seen much. I’ve had the scope just over two years, and while large periods of time in there were “down time”, I have used it a fair number of times. Almost always on my own though, and never with another scope right beside me to show me what I “should” be seeing. Or not seeing, as the case may be. Even in the dark skies near my inlaw’s cottage, I saw interesting things, but no nebulae, no galaxies. Variable stars, definitely planets, but no real deep sky objects (DSOs). It has been rather frustrating, and I was never quite sure what the problem was. A couple of times I felt like almost pitching the hobby, since I didn’t see much more than planets. Cool, sure, but long term without photography? I wasn’t sure what the problem was, but I was determined to find it before giving up the hobby.
A few weeks ago, I was at a star party organized by the RASC Ottawa Centre out in Carp (just west of Ottawa in a dark parking lot). After most of the lookie-loos had left, I was talking to a guy next to me who was showing the Ring Nebula, so I popped over, looked through his scope and there it was, clear as day. I went back to my scope, pulled up the Ring Nebula from my menu, slewed to it, and nothing. Nothing even close to it in my scope. His scope was different from mine (a Dobsonian), but not any more powerful, so I said, “Shouldn’t I be able to resolve it too?”. He said of course, came over, looked through the scope and said, “Hey, your alignment is off”. And with those five words, my random series of possible problems collapsed to a range around one. He adjusted my scope, I looked, and sure enough, there it was, easy peasy lemon squeezy. I didn’t know whether to laugh in relief that my scope could resolve it or cry because I’d wasted 2 years trying to figure out how to work it properly.
The larger range of possibilities
I had been wondering if the problem was amongst a bunch of possibilities. First and foremost, it was possible my eyes were just not good enough to see the faint objects. I am getting older, turned 47 recently, and as you get older, fainter objects are harder and harder to see. But when the other guy put my scope on the Ring Nebula, that possibility was clearly eliminated.
Second, I wondered if my scope wasn’t good enough. I had bought one of the higher-end entry level scopes, but wondered if maybe I’d chosen wrong (sacrificing viewing too much) or just got a lemon with bad optics. But the Ring Nebula was visible, so not optics. Neither the scope nor of eyepieces either.
Third, I had been wondering if maybe it was the suburban skies — perhaps they were just too light polluted for me to see these things, as most of my viewing happens in city parks, etc. While this was a darkened parking lot, it is by no means a dark site, so no problem there.
Last, I had considered it might be an alignment issue, but planets were always aligned, and most large stars like Antares, Polaris, etc. But with this guy’s five minutes of help, all the possibilities collapsed to this one…my alignment was off.
Fixing alignment
As with the larger range above, there are lots of reasons why the scope could be misaligned. With the help of some people online who have the same scope, and the people at the store who sold me the scope, I compiled a list of things to try.
The first thing I had to check was the physical setup. My scope was always pretty level early on, so I had stopped fussing about it too much. Never seemed to make much difference, the computer knew where the stars were, so I was golden, or so I thought. I’ve added a bubble level app to my phone and now use that to try to get my mount as level as possible, still using the vibration pads to limit shake.
Next, I looked at the initial computer setup. Normally, I keep it set for Ottawa and just have to put in the time and location. That has always seemed a bit general to my mind, but since the computer always seemed to figure it out, I went with it before. This time, I upgraded to a wifi connector that ties directly to my phone — which gives it my precise GPS location as well as local time down to the second. Can’t get much more precise than that.
Third, I have been really inconsistent with my choice of stars. I would say generally I was choosing stars in a 90-120 degree section of the sky most of the time. In some cases it was simply because that was the part of the sky I could see, other times it just happened to be where the first few bright stars were located. Other times, when I was particularly impatient, I’d even used planets as one of the three stars in the three-star alignment process. The computer let me do it, and I’d read instructions online that said you could do it — I didn’t realize they were saying you could do it, not that you should do it. Using a planet apparently adds in a lot of variability to the calculations, as does using stars close together. So, I changed my setup — I now use stars as far apart as possible, and try to cover as much of the sky as I can in my setup with three stars far from each other. Almost like an equilateral triangle in the sky.
Finally, I have always had a question about which eyepieces to use when I’m aligning. The scope comes with a 25mm plossl, but I also have a really nice 17.3mm Televue, a 10mm Televue Delos, and an 8mm Televue plossl. I was never sure how zoomed in I should be to say it was centred in the scope but I tended to use the 17mm lens. Both the online community, the help pages for the scope and the store had the same recommendation for change — buy a 12 mm red-lighted reticle eyepiece and use that to ensure it is centred. If that sounds confusing, it is basically a higher powered eyepiece than the one I was using before, and the red light reticle is an illuminated cross-hairs design…put the star in the centre of the crosshairs and tell the computer it is aligned. No guessing if it is in the “centre” of the eyepiece — it’s dead centre when it’s in the cross-hairs.
I had four other possibilities to try messing with if these four didn’t fix the problem … it could have been the mount itself (I had problems with gears meshing last year, but this problem predated that issue); my scope could have been out of alignment on the optics (had already checked that a few months ago, still perfectly aligned); my diagonal coul d have been out of whack (which could be checked at the store); or my firmware on the mount could have been out of date. They were on my list of possibilities affecting my alignment, but the others were easier to check first against “normal” setup.
The results
Apparently, I’ve just been a complete idiot for two years. If the guy at the star party hadn’t told me that my alignment was off, I’d still have been struggling to find the problem. I did the four steps above (physical leveling, wifi with coordinates, better star choices, and a illuminated reticle eyepiece).
Got it all setup, but had a lot of trouble with focusing on stars the night I tried due to haze (just bad seeing), took me more than an hour to align. And then as I was just about done, my wifi connector dropped the signal and I lost my setup. So I took a fifteen minute break, let some clouds pass by, and then tried again. Five minutes and I was done.
First test was a planet, but that was too easy. So I chose the Ring Nebula. And BAM! There it was. Easily seen from my light polluted park. It was awesome. I wandered around the sky on the app just trying out a bunch of things. I still have not seen the big galaxies, not quite sure why those are not resolving but could have been time of day. Clusters are perfect. Double stars. Variable stars. Everything shows up. It isn’t quite centred each time, but it’s within the field of view, so the margin of error is manageable. Over time, I hope that will improve as I improve my alignment procedures.
Overall though, I’m back on track. As I said earlier, I can’t decide between being happy everything is working the way it should or that it didn’t work for the last two years because I didn’t know what I was doing.
I’m sure there are lots of people reading this and laughing because they think anyone who uses a go to scope is an idiot anyway. Feel free to do so, but it just means you missed the upfront side of things. I do know how to star hop, and I can find things, but it’s not how I’m wired…when I’ve done it, I can find stars, but nothing else. Now I can use the GoTo scope to at least let me see what it is I’m supposed to find, and then learn to starhop between things better with some expectation of success. It’s also a bit of the reason why I’ve struggled on my own for 2 years — there are a lot of nobs out there who basically turn into technique snobs and rather than help someone who is learning to do it one way, they instead say “Oh that way is stupid, here’s the only way to do it.” Different strokes for different folks.
But one guy who helped for five minutes with no attitude or judgement altered my entire experience. I’m back “in” for the hobby, and I never even caught his name.
