Saturday, November 27, 2021


Issue 577: Unks’s Advanced VX Rides Again


Yeah, I know, no blog entries for September and October and we’ve barely squeaked in for November. I hate to disappoint my readers, but there just wasn’t no way, muchachos.  The weather was nasty all through September and into October. On those infrequent occasions when the clouds parted, there was a big, fat Moon in the sky. 

Your broken-down old Uncle had also been experiencing some health issues that made him reluctant to hit the backyard. You know, this “getting old” stuff is for the birds. Finally, just as clear weather came and Unk began to feel more like his old self, a third shot of Moderna had him laid pretty low for a couple of days.

Thankfully, all that is now past, and I am indeed close to being my old self again for good or ill. In fact, this past week I felt Good Enough to tackle my number one astronomy priority, checking out my Celestron Advanced VX GEM mount. If you’re a faithful reader of the Little Old Blog from Possum Swamp, you know my AVX took a bath some months ago. I’d left the mount outside under a Telegizmos cover. Said cover was beginning to show some wear five years down the line, but it had not had a huge amount of use, and I thought it would be OK.

That’s what I get for thinking. I noted some gathering clouds as I covered scope and mount following my backyard observing run, but it didn’t look like seriously bad weather was on the way. Unk was soon snoozing peacefully and was not fully awakened by the sound of heavy rain and thunder. Oh, I came somewhat to my senses, but thought, “The scope will be fine under that cover,” turned over, and went back to sleep. The next morning, I found that dadgummed Telegizmos cover had leaked and mount and scope were truly drenched.

What to do? I first addressed the C8, Emma Peel, my Edge 800 SCT who’d been riding on the mount. There was a little water in the tube. But as you know, your ol’ Unk is nothing if not experienced in pulling SCT correctors. In just a few, the scope was dry and snug again in her case. The mount? That was a different story. It looked wet enough that I thought there was likely some water intrusion. Removing the plastic cover of her electronics enclosure, I did note some dampness. Rut-roh Raggy…it doesn’t take much to cause problems.

What I did was dry the boards off with gentle heat from my heat gun, and leave the mount head open in the air-conditioned sunroom of the New Manse. For several days. I then had another look. Didn’t notice any signs of corrosion, soo….  I applied power and the AVX appeared to function normally for an indoor “fake” alignment. However, nothing would tell the tale like a long evening under the stars. And there things rested for a wearyingly long time.

Finally, just the other day, the Clear Sky Charts and other weather resources indicated I might get some clear—if cold—weather following a front passage. Maybe one night. I was determined to take advantage of that, and despite some high haze I got the mount into the good old backyard.  In the interest of keeping things simple, I left the StarSense camera and hand control in their box and just plugged in the good, old NexStar+ HC. It had been so long since I’d done a non-StarSense alignment, I wondered if I’d still remember how to do one.

Which telescope went on the mount? My SkyWatcher 120mm APO. It had been way too long since I’d used this pretty telescope and was anxious to point her—Hermione Granger is her name—at Jupiter before it was too late. It was pretty clear seeing wouldn’t be too hot, not hardly, but I wanted a look at Jupe anyhow.

As darkness fell at a blessedly early hour—if Unk stays up till 2200 local time these days, that is a late night—a look to the west showed for the first time in some years I was going to miss one of my rituals, “My Yearly M13.” I wasn’t surprised. I’d checked Stellarium the previous morning and it showed M13 would be really low as astronomical twilight came in. That was sorta OK. To tell the truth, though I was feeling better, I still didn’t feel up to messing with cameras and laptops and guide cameras and etc., etc., etc. 

OK, power on…the NexStar display came to life with only a slight delay despite the cold weather (it was in the fricking 40s, y’all). I was gratified to see the mount's real time clock was only off a few minutes despite it having been months and months since I replaced the little internal battery and not having used the AVX frequently. Not at all. Hokay, let’s get aligned.

By “aligned,” I mean the Autostar 2+4 alignment. I planned on nothing more than some casual looking, and, so, my polar alignment consisted of merely eyeballing Polaris through the mount’s hollow polar bore. One of the great things about the Celestron NexStar goto system is that it is quite immune to goto errors caused by polar alignment.

It turned out I did remember how to do an old-fashioned alignment.  Got it started and the HC requested Vega, which was pretty far off center, but still in the finder. Centered it up in the eyepiece, remembering—shazam! —to do final centering with the up and right keys only. Altair next. That sparkler lined up, the NexStar+ axed if I wanted to add calibration stars “Sure, why not?” The first, Fomalhaut, was behind a tree, so I picked another. Calibration star three was near-centered in the eyepiece of the main scope when the mount stopped, but I did one more anyway…well…just because I could.

The resulting alignment? It was a good one. For a while, anyway. Anything I requested was in the center of a 12mm eyepiece. Heck our first target, Jupiter was centered in a 7mm when the slew stopped. And that’s the way it was until I decided to fetch my observing chair, and in the course of placing it at the scope bumped the tripod, but good. Henceforth, objects were toward the edge of the 12mm, but always in view. And…that’s just the way it goes on an Uncle Rod observing run, as you surely know if you’ve been reading here long.

How was Jupiter? The wind had laid down at least, but, no, the seeing was not very good. He was reasonably sharp and showing off multiple belts, but conditions were reducing the contrast of those belts. The Galilean Moons were dancing around most of the time. Not a bad image in the 7mm UWAN (William Optics) wide field, but nothing to get excited about. What was exciting? Just being able to get out and run an eye across the King, no matter how he looked.

Next up? If I couldn’t take a picture of the Great Globular, maybe I could get a parting glimpse of him as he plunged into the west. By this time, M13 was maybe 15-degrees above the horizon. Alas, when the slew stopped and I inserted the 13mm Ethos I saw exactly nuttin-honey.

I wasn’t about to give up. I suspected the problem was the focus difference between the 13 and 7mm eyepieces. I should have focused the 13mm before I left Jupiter. Down here in the horizon muck, no bloated stars were visible in the field to use for focusing. So, off I went to Vega to focus. There I sharpened things up. Did I note the utter lack of false color displayed by the SkyWatcher APO? Nope. After this long, I just take it for granted. Vega was a pure, icy blue sapphire.

Back to M13. I spotted the cluster the moment the slew stopped. Not bad, really. Dim, sure, but grainy and wanting to show a little resolution. Would more magnification have helped resolve more stars? Perhaps, but the cluster was dim as it was. Pouring on more aperture would have helped, but I wasn’t about to lug out the 10-inch Dobsonian, Zelda. The SCT? My observation is there’s not a huge difference in visual images presented by the 8-inch SCT and 5-inch APO, not enough to justify me changing OTAs, anyhow.

What next? How about M57? OK. To Lyra we went. The Ring was just that, a perfect little donut displaying plenty of contrast. Since the constellation was riding high, I thought we might essay the somewhat dim globular cluster M56. It was actually pretty good, looking much like the horizon-bound M13. My observation over the years has been it takes about 10-inches of aperture to make this somewhat neglected glob look good. And 12-inches is better. My long-gone old friend, my 12-inch Dobsonian Old Betsy, could make this seemingly nondescript object into a freaking showpiece.

The next target, M76, the Little Dumbbell is thought by some to be “difficult.” Not so. I once viewed this little sprite with my old 60mm ETX from deep in the light polluted suburbs, at my old observing site at the public schools’ Environmental Studies Center. The secret is an OIII filter. But it has to be the right OIII filter. I walked into the sunroom and fished a little box labeled "OIII" out of my accessory box. Onto the 12mm it went--with some difficulty. I was nonplussed that for some reason it didn’t want to thread onto the eyepiece properly. With the filter finally in place, still no M76 did I see. What the—?

My red flashlight revealed the problem. On the edge of the filter-holder was inscribed “Lumicon.” When I bought this one in 1995, I thought it was the bee’s knees. But either it has somehow degraded over the years (possible, I guess), or I just know more about filters 25 plus years down the road. At any rate, this old thing (one of the pink-hued Lumicons) doesn’t work very well, and the filter threads on it were never quite right. In I went and retrieved my Celestron (Baader) 1.25-inch OIII. Ahhh…there it was. Not only was the mini-Dumbbell visible, it even showed off its twin-lobed shape.

After that? Hermione and I hopped around the sky, me occasionally looking at SkySafari on the iPhone for inspiration. In no particular order…

M103. This oft-overlooked small (6’) but brilliant galactic cluster was just beautiful.

M31 and company. M31 looked maybe a bit better than it usually does from the suburbs. M32 was a brilliant little thing, naturally. M110 was something of a surprise. It was easily visible despite sometimes being a trial from compromised skies.

M27, the (big) Dumbbell was attractive, especially with the OIII. Unfortunately, haze was developing in Cygnus area, and I had a hard time seeing nearby M71, the loose little globular star cluster once thought not to be a glob.

NGC 457, The E.T. Cluster. Does this little guy ever look bad? Well I remember showing him off to Miss Dorothy from the urban backyard of old Chaos Manor South. He looked good there, and he looked great here, a little stick figure awash in a sea of stars.

M15, The Horse's Nose Globular. Haze was creeping into the Pegasus area now, so I didn't expect much from this little glob. Surprise! In addition to M15's preternaturally bright core, quite a few teeny-tiny stars were on display at the edges of this wonder.

And on we went. Me and Hermione wandering the late autumn stars, going wherever our fancy took us. You know I strongly endorse having a detailed observing list. Which I didn’t have on this night—I was just going to do a quick check of the mount on an object or two, I thought. I probably would have seen more if I’d made one up or had dragged out a laptop running Deep Sky Planner. But you know what? For once, just tramping aimlessly across the sky was kinda fun…kinda freeing, actually.

Alas, before long, old Unk had reached his infamous “I have had enough” stage. Those of you who know me or who’ve been aboard this blog for long know that happens once my feet get cold. When they do it is time to throw the big switch and cover the scope. Which I did. Said cover being a new one, which I hope proves to be better than the lastun.

As for the mount, the Advanced VX, I was satisfied all is well with it. Not a single hiccup from power up to power down. Which is a very good thing. I need a mount in this weight/payload class, and with anything that comes from China—as the AVX and her cousins do—being nigh impossible to get these days, I certainly wouldn’t want to go mount-shopping right now.

Alrighty then. See y’all next time. Which will surely be by Christmas Eve for our traditional blog post. But I do hope “sooner.”


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