When in Doubt, Read the Manual: An Evening of Terrestrial Observation
OK it wasn't the best observing conditions tonight, but I wanted to shake down the GoTo and Auto Tracking functions of my new SkyWatcher 12” Dobsonian scope, and I could do that easily from my back yard (at least until the fog rolled in!).
I have rediscovered that old adage "when in doubt, read the manual." Being a Mac user, I had fallen out of the habit of reading manuals; I expect things to "just work." And it turns out that the Sync Scan telescope tracking system does just that—almost. I was complaining to fellow RASCal Tony McGrath just last night that the GoTo seemed "off"—it would get 99% of the way there and stop. I wasn't happy! This is my first-ever GoTo so I have zero experience. He suggested a lot of helpful things, including leveling the mount before starting. I thought leveling was not all that important, but tonight I learned that if you take the time to do this, the mount is much more accurate. I suppose I thought that the 2-star alignment took care of everything. Anyway, tonight I used one of those inexpensive bubble levels to level the mount with some shims. Why they don't build one into the 'scope, I don't know. Jeez I spent enough on it!
I aligned the mount on Arcturus and Vega. The included GPS (not usually standard) helped by figuring out the lat/long/date/time/time zone. This saves a lot of data entry at startup. (The first time I used this it took ages, because the GPS has NO idea where it was at all.) Then I took a deep breath and asked the scope to find the Ring Nebula (M57). Bingo! It slewed to M57 and it ended up near the centre of the 42x eyepiece with a little over a degree FOV. Then I zoomed in with the 250x eyepiece and adjusted the aim. Nice view! The Sync Scan has a Position Accuracy Enhancer: when you are dead on the object you push the PAE button and then the pointing system is finely calibrated within 5 degrees or so. Without changing eyepieces, I asked it to slew to the Double Double in Lyra, and the 4 stars ended up nicely in the 14' restricted view of this eyepiece. Not too shabby! I looked around at a couple of objects in the data base and I found them easily enough.
The tracking is pretty good as well. You can walk away from the telescope and come back later and the object is still there! Auto tracking does not require a full star alignment, but (again) it does require moderate leveling and pointing the telescope north before you start.
Considering the poor conditions, I saw some pretty neat stuff in the telescope, including some double stars that I would have had difficulty star-hopping to in the light-polluted sky.
I am hoping to take this 'scope to Keji next week for some dark sky viewing and shake down the optics!
Dave Chapman is a member of the Royal Astronomical Society of Canada, Halifax Centre, and editor of the RASC's annual Observer's Handbook. When not looking up, he is digging weeds out of his vegetable garden or picking his guitar. Retired from 31 years of public service, he wonders where he found the time to go to work.