Archive for the ‘NexStar 8SE’ Category


Unboxing fest, part 2: Celestron f/6.3 focal reducer-corrector

October 3, 2020

Even before I had decided to get the NexStar 8SE, I knew that if I got a big SCT, I’d want a focal reducer-corrector for it. SCTs and Maks have secondary mirrors, which partially obstruct incoming light. This implies a necessary tradeoff: make the central obstruction small, which results in a long focal ratio–typically f/10 to f/15 for commercially-available SCTs and Maks–or get a shorter focal ratio by using a larger secondary mirror, which blocks more light and degrades the contrast.

There is a third solution, which is to use a focal reducer to make a steeper light cone and a shorter focal ratio. Astrophotographers use these all the time to making their scopes optically ‘faster’ so they can get brighter images with shorter exposure times. For SCTs they are useful because they bring the focal length of the scope down to something more reasonable, and increase the true field of view. As shipped, the Celestron C8 OTA has a focal length of 2032mm, so even a 32mm Plossl gives 63.5x, and the included 25mm Plossl gives 81x. The max true field of view with 1.25″ eyepieces is about 0.7 degrees, which can be a little claustrophobic. You can juuust fit the Double Cluster in a 32mm Plossl, as long as you don’t mind clipping the edges of both clusters. You can get M81 and M82 at the same time, as long as you don’t mind parking them on the extreme edges of the FOV.

The Celestron f/6.3 reducer-corrector turns the C8 from an f/10 to an f/6.3, with an effective focal length of 1280mm, which is pretty close to the mid-sized commercial Dobsonians–the XT6, XT8, and XT10 and equivalent models from other companies are all 1200mm scopes. That pushes the max true field to something like 1.2 or 1.3 degrees, which is a big jump over the native 0.7 or so. That’s enough to put some of the larger celestial objects, like the Pleiades and M44, back in a single field of view, although the Pleiades will be cutting it mighty fine (I will test this and report back!).

As the name implies, this unit is not just a focal reducer, it’s also a corrector, which makes the field flatter for better image correction across the entire field of view. In other words, stars at the edge of the field should still look round with this thing in, as opposed to oblong. This isn’t a factor for me–I don’t photograph stars, and the stars at the edge of the field in the C8 haven’t bothered me so far–but it’s nice to have if either of those things change.

Here’s the gizmo, out of its (unsealed) bag, with its custom dust caps. I got mine from Astronomics (here), and evidently it was one of the last they had, because the availability listing there says “More on the way”. Amazon has it, too (link), I just like supporting brick-and-mortar telescope stores and specialized astro-gear dealers whenever I can.

Why am I bothering to do an elaborate unboxing post for such a trivial piece of gear? Mostly because it took a lot of digging for me to figure out how one was used. What I wanted was a photo essay that showed how “this part goes here, that part goes there”. When I couldn’t find one, I decided to create my own.

Here’s how the NexStar 8SE OTA comes as shipped, with a 1.25″ visual back on the rear port. When I was first getting into this, it took me forever to understand what a “visual back” was. Did it mean anything other than the bit where you stick the eyepiece or diagonal? And if not, doesn’t every telescope have one?

The answer is that not everyone sticks an eyepiece or diagonal at the back of a scope. Some people put a camera, or a spectrograph, or who knows what else. So if you are going to use the scope visually, you need a doohickey that holds the eyepiece or diagonal, and that’s the “visual back”. It was just new to me because non-SCTs aren’t generally described as having a “visual back” (some high-end astrograph refractors excluded), they just have focusers.

ANYWAY, the focal reducer-corrector threads onto the rear port of the scope, after the visual back has been removed.

Then the visual back screws into the focal reducer.

Then you put eyepieces or diagonals into the visual back, as usual. Everything is just scooted back 3/4 of an inch or so by having the focal reducer interposed between the scope and the visual back.

Incidentally, this is something to keep an eye on for NexStar users: when the scope is pointing high, the diagonal already comes pretty close to the base of the mount, depending on how far forward the OTA is scooted in the dovetail clamp. I’ll have to mess around with the system, but I might have to start mounting the scope a smidge farther forward to make sure the diagonal clears the mount when observing up high.

And here’s where the last post and this post come together: the Baader Hyperion 8-24mm clickstop zoom eyepiece, riding in an Astro-Tech dielectric diagonal, inserted in the stock 1.25″ visual back that came with the C8, screwed into the f/6.3 focal reducer-corrector. All saddled up and ready to go (er, minus the finders). Now all I need is for night to fall.

I have one more piece of gear to write about, but it hasn’t come in yet, so the next post might be an observing report–hopefully, a first-light report on the focal reducer and the Baader zoom. Stay tuned.


Full moon, 1 Oct. 2020

October 2, 2020

My first decent moon shot in ages. Handheld iPhone 7, shooting through a Celestron NexStar 8SE and an Orion 32mm Plossl, contrast punched up using curves in SnapSeed.


Observing Report: the Smoky-Tex Star Party

September 26, 2020

In the recent post on my new NexStar 8SE, I promised to explain why I was moving quickly trying to get the scope and the mount checked out. It’s because I knew I was bound for darker skies.

This is Black Mesa, at the extreme northwestern corner of the Oklahoma panhandle. The mesa is named for the thick cap of black basalt, the product of sporadic volcanism in northeastern New Mexico over the last 20 million years or so. The basalt is capping a sequence of sedimentary rocks in which portions of the entire Mesozoic are represented, including Cretaceous sandstones, Late Jurassic limestones, clays, and mudstones, Early Jurassic aeolian sands, and Triassic sands, shales, and muds. That’s what normally takes me to Black Mesa: digging dinosaurs.

The extant vertebrates aren’t bad, either. I took this photo on my very first visit out there, in 2016. I’ve been back to dig almost every year since.

Black Mesa draws visitors for another reason: inky-dark skies. On this light pollution map, I’ve highlighted Utah and Oklahoma in white, and circled the field areas of my digs in pink. It’s not just paleontologists that are drawn to such remote areas. The Okie-Tex Star Party is held each year just outside the tiny town of Kenton, less than five miles from our dinosaur quarry.

I’ve been wanting to go to Okie-Tex for ages, but every year before this one I was too busy teaching at this time of year. This year my schedule would have allowed me to attend, but of course the star party was cancelled because of the damned pandemic (correctly, I might add). I had planned to meet up at Okie-Tex with my friend Reggie Whitten, one of the founders of the Whitten-Newman Foundation that supports our dinosaur dig out there. The WNF has a cabin near Black Mesa, and when Reggie heard that Okie-Tex was cancelled, he said to me, “Hell, Matt, come on out and we’ll have our own star party”. I knew this was coming from a couple of months out, and that’s why I was scrambling to get the new NexStar 8SE up and running: I wanted it to be my star party scope.

I started the drive out two Wednesdays ago, on September 16. It’s 1070 miles from my driveway to Black Mesa. The first day, I made it as far as Santa Fe, New Mexico. At home, I’d been stuck under groady, smoky, ashy skies since the Mount Baldy run at the start of the month, and even though I’d been on the road for 12 hours, I was craving starlight. So I drove out west of town, past the airport, found a deserted dirt road, and spent half an hour cruising around the sky with the SkyScanner 100, shown above, and 7×50 binoculars. The skies weren’t crazy dark–the light dome from Santa Fe reacted with the humidity in the air to wipe out everything from the nose of Pegasus to Cassiopeia–but I still had fun looking south and west. I caught Jupiter, Saturn, M11, M57, M56, Albireo, Alpha Vulpeculae, Brocchi’s Coathanger, M71, M27, the heart asterism around Sadr, M29, and M39. I hit the gas giants again at the end of the session, checked in on Mars, and called it a night.

The next day I mostly counted pronghorn while I drove. I love these goofy critters, and there are a lot of them in northeastern New Mexico. Between Santa Fe and the Oklahoma border I counted at least 110, in 17 groups. Not many people know that pronghorn are so ridiculously fast–60 to 65 mph–because they evolved to outrun the now-extinct American cheetah, Miracinonyx, which was probably not a true cheetah but a convergently-evolved offshoot of the North American mountain lion or cougar. Pronghorn are not only fast, they also have a preternatural ability to tell when I’m about to take a picture, at which point they bolt. So I have a lot of photos, like the one above, that show pronghorn butts as they run away.

NB: not a pronghorn.

I got in Thursday afternoon and started unpacking scopes. I’d brought four: the NexStar 8SE as my main ride and big gun, at least for this trip; the C80ED as the next-nicest backup scope in case conditions were too windy for the big C8 (that would be prophetic); the Bresser AR102S for rich-field observing; and the SkyScanner 100 because I wanted a reflector along so I could demonstrate the three main types of telescopes, and because why the heck not.

That first night was the best. It got cool, down in the 50s, but there was no appreciable wind, and the seeing and transparency were both phenomenal. On the planets and bright deep sky objects like the Ring Nebula, I just kept throwing shorter eyepieces into the C8 until I hit the 5mm MWA, which is currently my shortest decent non-Barlowed EP. I only realized the next day that the 5mm was giving 406x in the 2032mm C8, which is a heck of a lot of magnification. Here in SoCal I find there are only a handful of nights each year that I can go past about 350x–and, frankly, for the stuff I observe I rarely need any more juice than that.

The next day, conditions took a turn for the worse. First, there was wind, which is normal for Black Mesa, we’d just gotten lucky the night before. My first solution was to roll with the C80ED instead of the NexStar, but the wind was so strong that even that small, solid scope on a very competent mount was bouncing around like crazy at anything over the very lowest magnifications. The next night, I had the better idea to repark the truck perpendicular to the wind, and put the NexStar in its lee, and that worked great.

The less welcome development was the arrival of, yep, smoke from wildfires. Here’s a shot of Black Mesa looking northwest from Robber’s Roost, scaled down a bit but otherwise unretouched–compare to the photo on a cloudy day at the top of this post, which was taken from essentially the same spot. I felt a little deflated to have crossed about a third of the US for exactly one clear night. This smoke was from fires in southern Colorado, and fortunately conditions got better quickly. We had one bad night of smoke, and then things got clearer every subsequent night.

For the entirety of my stay, I was the sole astronomer in a small and ever-changing group of civilians. Almost every time out, there was at least one person who hadn’t been with us the previous evening, and consequently I spent a lot of time showing people the best and brightest objects: the Ring, the Dumbbell, M13, the Double Cluster, Andromeda, and so on. And of course, Jupiter and Saturn and Mars. Not that I’m complaining! Those crowd-pleasing objects look good from home in small scopes. Under Bortle 1 skies with 8 inches of aperture, they looked phenomenal, and I would have spent most of my time observing them even if I’d been completely alone. The Double Cluster just fits in the field of a view of a 32mm Plossl or 24mm ES 68. You could spend a long time gazing into the depths of those two clusters, and many of my companions did. Different people had different favorites: the Double Cluster, the Ring Nebula, Andromeda, but the winner for most was Saturn. Which is entirely reasonable–even after all these years of stargazing, it’s a kick in the brainpan. Every single time I look at Saturn through a telescope, I am forcibly confronted with the reality that while I’ve been dealing with meetings and oil changes and dentist appointments and grocery shopping, it’s been out there for billions of years, vast, majestic, and serene, supremely untroubled by all the traffic jams and mass extinctions and whatnot transpiring on this wee little rock far across the solar system.

One morning I got up at 4:00 to go on dawn patrol. Several folks had indicated that they might join me, but the only one who actually did was Rachelle Whitten-Newman, Reggie’s spouse. We spent an hour and a half rocking through Orion, Taurus, Monoceros, Gemini, and Auriga. The Orion Nebula looked about as good as I’ve ever seen it, and M37 looked like diamonds on black velvet.

Ad Astra: the official wine of our star party.

Allow me to impress upon you just how darned dark it is out there. In the whole valley between Kenton and Black Mesa, there are about two porchlights on at night. The headlights of a car coming over the local horizon, 3 or 4 miles away–which does not happen very often–look like spotlights. The closest towns are Boise City, Oklahoma, population about 1200, which is 38 miles east, and Clayton, New Mexico, population about 2900, 45 miles to the southwest. You could draw a circle with a radius of 50 miles around Black Mesa and probably sweep up fewer than 6000 souls (the same circle around my house in Claremont would get 10 or 15 million). There are no light domes on the horizon. The major sources of light pollution are the planets themselves.

One night after packing away the telescopes I was sitting on a folding chair outside my tent, just taking in the night sky, when I realized that the entire landscape was very dimly illuminated. I can hardly stress enough how faint was this illumination–it was to the light of a bright moon what moonlight is to sunlight–but it was enough to cast pools of jet-black shadow under the cedars, the vehicles, and the awnings of the tents and buildings. I looked up to see the source of the light and the only possible culprit was Mars, soaring high overhead in the middle of the night. That’s right: out there, Mars casts shadows.

The NexStar 8SE performed like a champ. I started every evening with a 2-star align, usually on Mirfak (Alpha Persei) and Nunki–the latter is the star in the handle of the Sagittarius teapot that is closest to Jupiter. After that, the scope was good to point all over the sky, and to track for longer than I ever needed it to. I felt a little spoiled. One night I was out by myself for a bit so I decided to rock through the Messiers in the western sky. Scorpius was getting low, but I caught all of the M-objects in the “steam from the teapot” in Sagittarius and Scutum, as well as all of the globular clusters in Ophiuchus and Hercules, in about half an hour. After spending 13 years finding objects myself, and nudging the scope along, it felt a little like cheating, but I also realized that I’d never done a careful comparison between, say, M10 and M92, because I’d never gotten to observe them within 30 seconds of each other. That’s an epiphany I would never have had if I’d never used a GoTo scope. So I am looking forward to exploring the full ramifications of how this new tool will affect my observing.

My C8 meets its biggest sibling: a C14 EdgeHD.

Oh! I almost forgot to mention the Talentcell battery pack. MAN this thing just keeps going. I charged it to full on the day that it came in. Here’s what it’s been up to since then:

  • Sept. 9: 4.75 hours of tracking, in the garage, down to 4 out of 5 charge indicator lights by the end
  • Sept. 17: 3 hours of slewing and tracking
  • Sept. 19: 1.5 hours of slewing and tracking, down to 3 out of 5 charge indicator lights by the end
  • Sept. 20: 1.5 hours of slewing and tracking
  • Sept. 21: 3 hours of slewing and tracking, still showing 3 out of 5 charge indicator lights

I haven’t had a chance to run it since I got home, but so far it looks like it will run the scope for 4-5 hours per charge light, so possibly 20-25 hours of scope operation on a single charge. Very, very happy with this thing. Now that I know that it works and the mount works, I need to velcro them together so I can stop moving the battery pack around on the eyepiece rack while the telescope is slewing, to keep the scope from unplugging itself. Here’s that model again if you’re wanting one (link). I couldn’t be happier with mine.

Yes, that’s the Bresser Messier AR102S riding on the table-top mount from the SkyScanner 100, which is itself riding on the Bogen-Manfrotto tripod. Believe it or not, at that moment that was the most capable rig I could assemble in a hurry!

All too soon, my time in Oklahoma was over. I saw even more pronghorn on the way home, at least 119 in 14 groups between Black Mesa and Santa Fe. At one point, while checking out a group of four that resolutely refused to run away, I set up a scope, and got my best-yet photo of one of these beautiful and bizarre creatures:

I’ve seen a lot more deer than pronghorn over the years, more often, and usually up closer, and I’m always struck by how different pronghorn look from deer. Their bodies are more compact and their legs even skinnier, like furry bullets on sticks. You can tell at a glance that they are built for a completely different level of speed. Marvelous animals. Long may they reign.

Later that day I made an ugly discovery, after sunset when I was barreling down I-40 west of Flagstaff: smoke from the California wildfires. It made a distinct layer in the air, visible from many miles away, as you can see in the above photo. As I-40 plunges off the western edge of the Mogollon Plateau it was like submerging in gunk. Up top, I’d been able to see for dozens of miles; I first saw the San Francisco Peaks rearing above Flagstaff before I even got to Winslow, Arizona, 60 miles to the east. When I came down into the low desert, visibility shrank to just a few miles, and I realized that the smoky air was lapping at the edges of the high country like water at a rocky shore. Yuck.

As it turns out, my astronomical adventure was not quite over. I made it as far as Kingman, Arizona, before I decided to call it and find a place to spend the night. I pulled into the Maverick station off Andy Devine Blvd, just north of I-40, and got a wrap and some yogurt for a late dinner. I walked around as I ate, to stretch my legs, and I discovered a big empty lot south and east of the store, crisscrossed with tire tracks. The moon was out, and at first quarter it looked like it had been chopped in half with a katana. I drove the truck out onto the dirt, set up the Bresser AR102S on the hood, and had a look at the moon, Jupiter, and Saturn. I didn’t spend long, only 15 minutes or so, but it was a nice coda to the trip.

What now? I’m back in SoCal, patiently waiting for the wildfires to subside, for the air to clear, and for it to get cool enough for London and I to go camping. I’m going to really enjoy having an 8-inch scope that doesn’t take up the entire back of the truck or require me to move 30-50 pounds at once. I’m going to enjoy having a scope that will track objects so I can sketch them. Who knows, I might actually get back to the Herschel 400.

And I’m going to miss Oklahoma. We had a pretty darned good run out there, despite the wind and the smoke. Reggie and Rachelle and company are already talking about turning our private star party into a yearly event, and I’m all for it. Many thanks to the two of them, to Jeff Hargrave, to Diane, Becky, James, Melissa, and Robert Newman, and to Noah Roberts for a fantastic visit. Clear skies, y’all, and keep looking up.


New scope: Celestron NexStar 8SE

September 20, 2020

London looking through the scope the first evening, when I had it on the AZ-4. His 60mm Meade refractor waits in the background.

Welp, I finally did it. I’ve been low-key lusting after one of these scopes for a few years now. Between 2007 and now, I’ve owned reflectors from 70mm to 300mm, refractors from 50mm to 102mm, and Maks from 60mm to 127mm, but I’ve never had a Schmidt-Cassegrain, and I’ve never had a GoTo scope. I figured it was time to rectify both of those omissions. What tipped my hand was the planets: I’ve had great fun these last few weeks observing Jupiter and Saturn almost every evening, and Mars on many evenings, as we speed toward opposition with the Red Planet in mid-October. Yes, the Apex 127 and the XT10 both do great on planets, but after a while I get tired of nudging them along, especially at high power. Also, the XT10 weighs about 55 lbs all set up and kitted out, and some evenings I wuss out. It will be nice to have something between the 5-inch Mak and the 10-inch Dob for those times when I want a little more oomph and a little less hassle.

If the NexStar 8SE is actually less hassle–I’m new to computerized scopes, or indeed even to motorized scopes, and my first night getting the whole system set up was not without some frustration. But I’m getting ahead of myself.

The first point in this saga is that the NexStar 8SE, like almost all NexStar scopes, and like almost all computerized scopes, and in fact like almost all scopes period, is almost completely sold out right now, from sea to shining sea. This is apparently less about the pandemic disrupting supply lines and more about a completely bonkers demand for telescopes during the era of COVID. A lot of people are looking for hobbies while they are stuck at home, and sales of astronomical gear are, well, sky-high, at least according to the vendors I’ve heard from via email or on Cloudy Nights. So it took some doing to find one. I usually prefer to support friendly local and not-so-local telescope stores like Oceanside Photo and Telescope, Woodland Hills Camera & Telescopes, Astronomics, and Orion, but none of them had the scope in stock when I was looking. Turns out, Amazon had a few, so I put in an order. Aaaaand…nothing. More than a week after I placed the order, the scope still hadn’t shipped, and there was no sign that it was going to do so anytime soon.

During the unboxing. Each big component is sandwiched in styrofoam or ethofoam, inside its own box, and all of them are in two bigger boxes. The square vacuity at the lower right held the box for accessories. Note the ruler sitting on the OTA–this is a big scope, in a big package.

Frequent commentor, sometime observing buddy, and telescope-purchase instigator Doug Rennie came to the rescue, with an AmazonSmile link to NexStar 8SEs that were said to be shipping in just a few days. I canceled the original order and tried again using Doug’s link (which is here — apparently the scope is still in stock). The scope arrived in just a couple of days, which is only surprising because the estimated delivery time was more like five days. It arrived in a big box: 3.5 feet x 2 feet x 12.5 inches.

On the day that the scope arrived, I had no way to power it. I had been planning to order a rechargeable battery pack (this one), but hadn’t gotten around to it; we were out of suitable alkaline batteries at the house; Vicki had the car to work a forensic case so I couldn’t drive to the store; and London and I were still sunburned from a trip to the beach the previous weekend so we didn’t want to walk to a store. I took a page from Uncle Rod (this post and this one) and put the C8 OTA on the SkyWatcher-branded Synta AZ-4 alt-az mount I got back when. The result looks goofy as heck but it works. At 17″ long and 9″ in diameter, the C8 is a voluminous scope, but it’s mostly air, and the OTA is not much heavier than the Apex 127/SV50 combo that I use on the AZ-4 all the time.

C8 OTA on the left, Apex 127 with rings on the right.

Here I hit a snag. The NexStar mount is left-handed, the AZ-4 is right-handed, so the C8 tube went on upside-down. That put the focuser knob above the visual back, diagonal, and eyepiece, rather than below, which was weird but not a deal-breaker. It also put the finder mount–a little Picatinny rail for the included red-dot finder–below the scope’s equator instead of above it. (I had the same problem with the Apex 127 back in the day, as discussed in this post.) I figured heck with it, I’d get by just sighting down the tube. I do it all the time with my other scopes, and it works okay.

Correction: I do it all the time with my other non-Cassegrain scopes, and it works okay because they have short focal lengths and wide fields of view. The C8 has a focal length of 2032mm and a max field of view of a little less than 1 degree. Getting the scope pointed at anything without a finder involved a tremendous amount of faffing about, like 5 to 10 minutes per object. It would have been way simpler to just mount the RDF and crouch down to use it. But like a bloody-minded fool, I persevered without, and managed to observe the following objects the first night out:

  • Jupiter – even at just 63x in not-great seeing, I caught the Great Red Spot easily in direct vision.
  • Saturn – also at 63x, immediately got 4 moons. I’m sure more would be possible on a night with better seeing. I ran the magnification up a bit, but didn’t see any more. That’s how it goes when the seeing is bad.
  • Moon – holy light-collecting area, Batman! At low power, with the entire just-past-full moon in the FOV, I heard a sizzling sound and a beam of moonlight shot out the back of my head. I ran the power up to 169x and saw subtle features in the maria that I’d never seen before, especially inside flooded craters on the margin of Mare Fecunditatis. Focus on the C8 was surprisingly snappy for a non-refractor–one second an object would be out of focus, then BAM, it was in, no question. I decided a star test was in order. But first, on the way to the pole:
  • Mars – brilliant. Even at 81x with the included 25mm Plossl, I could see a wealth of detail on the surface, including the dark triangle of Syrtis Major.
  • Polaris – used this for a star test. Happily, the collimation appears to be dead nuts on. The star test looks excellent. I hauled out a copy of Suiter’s book, Star-Testing Astronomical Telescopes, which is on loan from a fellow club member. Any problems with the optics are below the threshold of my ability to diagnose. This is consistent with the fine details and low-contrast features I was picking up on other targets.
  • Vega – I just used this to get on target at Epsilon Lyrae, but I was happy to see no chromatic aberration. I did catch just the faintest whiff of greenish-yellow on the limb of the moon, but I can’t be sure that wasn’t in the eyepiece. Long planetary and lunar sessions with the Apex 127 these past few weeks have shown me that eyepiece CA is real, and varies a lot between makes and models.
  • Epsilon Lyrae – by now the seeing had turned to crap again, at least in the west. I only ran up to 169x and the stars were still too shimmery to “black-line” split, but I was happy to see that they were elongated into little 8s at 81x, which makes me think this scope will split the Double-Double below 100x on a still night. That’s not any huge achievement, but it’s nice to know the scope is performing within expectations.

In sum, the scope is optically great. I’ve been pretty lucky with most of my scopes, but I’ve had a couple of stinkers, so it’s nice when they turn out better-than-expected, which this one certainly did.

In fact, it was a little anxiety-inducing. I really, really wanted the mount to work, too, so I’d have no reason to return the package and lose such a nice OTA. Yesterday (Thursday) I had to run some errands anyway, so I picked up some batteries. By this time I had a rechargeable external battery pack on the way, but not yet in. So I murdered some AAs to try out the mount.

The accessories that come with the NexStar 8SE. Clockwise from the upper right: a bubble level for leveling the tripod before you put on the mount and telescope; a 25mm Plossl (of course!); mirror star diagonal; and the hated red dot finder (RDF).

First thing: you really, really need a finder to get the scope aligned for GoTo. Which means the finder needs to be aligned to the scope, and I foolishly had not done that during the day. Have I ever said how much I hate, hate, hate red dot finders? My first accessory purchase for this scope, after the external battery pack, was a 9×50 RACI, again from Doug Rennie, who had gotten one for his NexStar 6SE but wasn’t using it. Anyway, after some faffing about I got the RDF on and aligned. Did a rough alignment on some distant leaves, then got it dialed in on Capella.

I had just watched a video Doug had sent on the Auto 2-Star alignment (this one), so I did that, starting with Capella. The suggested second star was Vega, which was still visible in the west. Got the alignment dialed in on Vega, then I was off and running.

First object I tried was M27. I couldn’t see a darned thing, BUT it was going down into the light dome over LA, and fighting the light of the nearly-full moon, so…who knows. After that I punched in Mars, and after the scope stopped slewing, Barsoom was in the eyepiece and looking good. Pleiades, ditto, although they spilled well beyond the sub-1-degree field of view. M34, ditto. Neptune, ditto, a tiny ball of blue floating out in the black. Then the moon, and like every one of the others, it was just about centered in the eyepiece. These objects were reasonably well-distributed over the sky, so I was pretty happy with the mount’s ability to get the scope on target. I let the scope just track the moon for a few minutes while I took some notes.

One thing–I had left the tripod legs collapsed for max stability, but even sitting down that put the eyepiece about 7-8″ lower than it could have been, and punishingly low on some high targets. I figured I’d elevate the scope a little more in future sessions. To figure out how much I’d need to raise the tripod, I punched in Aldebaran to get a low-in-the-sky target, and the scope slewed right to it. I spent a few minutes using the hand control to drive around the Hyades, looking for double stars, then stopped to write some more notes. Have I mentioned that I’m including more double stars in my observing these days? Blame the Astronomical League’s Double Star and Binocular Double Star observing programs, for acquainting me with so many fetching targets.

At this point the mount had been on for about an hour. I tried for the double star Eta Cassiopeia, and the scope drove to Cass, but not to the star. I wondered if the batteries were dying–apparently GoTos lose their minds as the power runs out–so I punched in Polaris, hoping to get one last target, but the scope slewed off to the east, in completely the wrong direction, and then stopped moving entirely. I flipped the power switch off and put everything away. The scope ran for a little over an hour on the AAs, which is in line with what others have reported. And also a fairly expensive session!

The NexStar 8SE set up just inside the garage, looking south over the car for some alignment and tracking testing.

So, the OTA was optically great, and the mount worked, did GoTo, and tracked objects. The Talentcell battery pack (this one) arrived the day after the AA-powered session. What I wanted to do was set up in the driveway for a long planetary session, to see how the mount and battery pack work during extended tracking, and to take the whole rig up the mountain soon to see how it would work on a multiple-hour session under darker skies. Unfortunately by this time ash from the wildfires was raining from the sky, and ash is hell on telescope optics, so both the driveway and Mount Baldy were out. Still, I was desperate to know how the whole rig would work together, so I set the scope up inside my garage, which has a south-facing door, and did some tests in the southern sky. After doing a two-star align on Fomalhaut and Nunki, the system was putting objects near the center of the FOV every time. I also tried a single-object solar system align on Jupiter, and that was good enough put objects somewhere in the FOV of a low-power eyepiece, and to track for 20 minutes or so, but definitely not as good as the two-star align.

Why was I pushing to get this scope and mount tested when conditions were so crappy? That will be revealed in the next post.