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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.

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Why I prefer RACI finders to straight-through finders and red-dot finders

September 26, 2020

My Orion 9×50 RACI finder mounted on my son’s XT4.5, at the Salton Sea.

Intro

A commenter on the last post asked why I hated red-dot finders. I wrote a short comment by way of explanation, but I realized that I had a lot to say on this issue, so I’m coming at it again with a full post.

Right off the bat we need to get something straight, and that is the difference between facts, on one hand, and preferences or opinions on the other. If I say that red-dot finders tend to be smaller and lighter than magnifying finders, or that straight-through and red-dot finders require users to put their heads lower than right-angle finders, those are statements of fact. I may be right or wrong about them, and if I’m wrong, I expect to be corrected. If I say that I don’t mind the extra weight and bulk of a magnifying finder, or that I hate crouching to look through a finder, those are my preferences. I can’t be wrong about them, any more than I can be wrong about liking egg salad and long solo drives. If you have different preferences, great! You can’t be wrong about them, either. It’s a big world, and there’s room for all kinds of preferences. Where we often get into trouble is when we (a) mistake preferences for facts, and (b) expect others to fall into line with our preferences. Maybe egg salad and RACI finders just aren’t your cup of tea. That’s fine, I can’t tell you that you are wrong.

So I will try to be as clear as possible in this post between the objective facts and my subjective preferences, and I expect to be called out if I get any facts wrong, or get any of those facts and preferences on the wrong side of the line.

With all that in mind, here are some issues that arise when we consider finders:

  1. Straight-through versus right-angle viewing
  2. Magnification
  3. Size and hassle
  4. Longevity

1. Straight-through versus right-angle viewing

The main difference in preference here seems to come down to just a handful of things: with a straight-through finder, whether magnifying or non-magnifying, you’re looking in the same direction as the telescope tube is pointed, which some people find more intuitive, and if you want you can use both eyes and overlap the image through the finder with the image through the other eye, whereas with a right-angle finder you’re looking in the same direction as the telescope eyepiece, which typically requires less head and body movement, and less crouching to get your head down behind the finder.

Sighting down the tube of my Apex 127 to get the finder aligned, using the top of a palm tree as a target.

One criticism that might be leveled at right-angle finders is that people using manual mounts often end up sighting down the tube anyway to get the scope in the right neighborhood, and as long as you are down there with your face against the tube, you haven’t actually saved yourself any ergonomic benefit over looking through a straight-through finder. My counter is that I’ve gotten good enough at “shooting from the hip”, just aiming the scope up at the patch of sky I want without sighting down the tube, that I can almost always put the target somewhere in the field of view of a 9×50 RACI finder. So I hardly ever sight down the tube. I realize that’s a personal experience and preference, not a universal one. (You can also get away from sighting down the tube by using a laser pointer as a finder, as discussed below.)

I prefer to sit when I observe, and I often observe things when they are high in the sky, and there’s no getting around the fact that if you do those two things, using a straight-through finder means crouching or kneeling on the ground. The only ways I know of to get around that are (1) putting the scope higher, which means either standing or using a really tall observing chair, (2) not observing near the zenith, which means giving up the darkest part of the sky, or (3) using go-to, where you only need to use the finder at all during setup, assuming the alignment is good and the pointing is accurate.

2. Magnification

Some people prefer magnifying finders, and others don’t. I prefer them, for a few reasons. First, a magnifying finder offers an intermediate step between naked-eye and ‘main telescope’ viewing, which I find especially useful for star-hopping. Particularly in dark areas of the sky, or under light-polluted conditions where big areas of the sky have all the naked-eye stars wiped out of visibility, I often need something between my eyes and the scope to help me get on target, even with the aforementioned sharp-shooting. Not everyone does, so that counts as a preference.

The Apex 127 with a little SV50 mounted as a luxo-finder and mini-RDF. The wide-field, low-power views in the little refractor complement the narrow-field, high-power views in the larger Mak.

I have also come to appreciate using a magnifying finder as an observing instrument in its own right. The finder offers a larger true field for big objects that might not fit in the FOV of the scope, and under sufficiently dark skies the finder serves as a miniature rich-field scope. From the Salton Sea, Anza-Borrego, and dark places out in the Mojave, Utah, and the Oklahoma panhandle, I’ve seen virtually all of the Messier objects in a 9×50 finder. As an enthusiastic binocular observer, I think of a 9×50 finder as a 9×50 monocular that I can park, and which I don’t have to worry about holding steady. I also find a magnifying finder useful for educating newcomers—I can have them compare the views in the finder and the main scope to learn about the tradeoffs of light gathering, magnification, and field of view.

3. Size and hassle

Here the point goes to the red-dot finder, and in fact most non-magnifying illuminated dot or ring finders. Even Telrads are voluminous but not heavy. So if size and weight are considerations, the RDFs come out ahead.

Also, dot- and ring-finders can typically be aligned with just two or three adjustment knobs. The spring-loaded finder brackets used for a lot of magnifying finders these days are equally easy to adjust, but the older two-rings-with-three-screws-each setups can be pretty tricky by comparison. They’re not exactly hard, especially once you get used to them, but they have a slightly steeper learning curve over the very simple alt-knob-plus-az-knob alignment of most red-dot finders.

I’ll say this for RDFs, they are much less hassle when you’re trying to balance a scope.

4. Longevity

Red-dot finders require batteries. So do illuminated magnifying finders, but non-illuminated magnifying finders don’t, so that’s a slight convenience win for them. More seriously, in my experience red-dot finders are the component of a modern scope with the shortest lifespan; in fact, they’re the only component that usually wears out at all (although reflectors eventually need their mirrors recoated). We use Orion StarBlast 4.5 scopes in the Claremont Library Telescope Program, which has been running so long now and with so many scopes that I have about 20 cumulative telescope-years of experience with that model. The RDFs always fail early in the lives of the scopes. After a couple of years of trying to fix or replace them, I started pulling the batteries and rewrote the instruction manuals to direct people to use them as peep-sights, and that has solved the problem to everyone’s satisfaction. So at a base level, I don’t trust RDFs because I expect them to eventually fail, and that’s not something I feel about any other piece of kit that I own or work with.

I see you, red-dot finder, but I don’t trust you.

The third way: what about laser pointers as finders?

I have to admit, I use a green laser pointer a lot as an auxiliary finder. Several manufacturers make GLP mounts that can be precisely aligned with the main scope. I tend to just pull my GLP out of my pocket and slap it alongside any straight edge on the telescope, mount, finder base, or focuser, and that’s good enough to get the 9×50 RACI on target–or the whole scope on target, in the case of the SkyScanner, which I modified with a bespoke wooden trough to hold a GLP. On my other scopes, I can do without a mount for the GLP precisely because I use a magnifying finder, which takes over where the rough laser alignment leaves off. I can certainly understand, though, why some people prefer permanently-mounted GLPs as finders, and if I didn’t like using mine freehand so much—or if I was willing to buy a second one—I’d be awfully tempted to do the same. I wouldn’t give up a magnifying finder, though, so I’d have to dual-mount.

Cheap GLP in the wooden trough I built for my SkyScanner 100. I got the idea from fellow PVAA member Ken Crowder, who had done something similar for his 8-inch SCT!

Conclusion

In summary, I don’t like the ergonomics of any straight-through finders, red-dot or otherwise; I don’t trust the longevity of the cheap came-with red-dot finders, and I’m unwilling to invest in better ones because of the ergonomic issues; I strongly prefer to have a magnifying finder as a second telescope mounted alongside the first; and I don’t mind the extra size, weight, and hassle that comes along with 50mm finders in particular. In fact, if 70mm and 80mm finders were cheaper, I’d probably have them sprouting from my telescopes like mushrooms. A 9×50 RACI finder was the very first add-on I got for my first telescope back in 2007. I’ve moved it around as needed to almost every other scope I’ve owned, so I’ve been using one for so long now that if I don’t have one on a scope, it feels like I have a limb missing. (The SkyScanner 100 gets a pass here, because with a 32mm Plossl in the focuser, the scope itself serves as a 12.5×100 right-angle finder, albeit with an inverted image, and the same goes for other super-widefield scopes like the Bresser AR102S.)

Every one of those things is a preference, not a fact. Obviously many other folks have other preferences—just witness the devotion to Telrads, which IMHO are about 10 times as large as they should be to do what they do. And using my new NexStar 8SE is gradually eroding my hate for RDFs. I have to grudgingly admit that the RDF is a handy tool for the initial 2-star alignment, especially because I tend to select alignment stars near opposite horizons, so I don’t have to crouch too much to use the RDF. I still do the first round of centering using the Celestron illuminated 9×50 RACI that I bought from Doug Rennie, and I check the finder on about half the targets just to see what they look like in the smaller instrument. But the RDF is clawing for a place in my kit, and possibly when I’ve used one as much as I’ve used a 9×50 RACI, my preferences will have changed.

What do you roll with, and why? The comment field is open.

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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.

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Resources for Naked-Eye and Small-Scope Observing

September 12, 2020

Allan Dystrup’s Classic Rich Field, and more

A few years ago, Cloudy Nights user Allan Dystrup started a thread called “Classic Rich Field“. It’s mostly about OB associations, and the early observations were all done with a Vixen 55mm f/8 scope. Later observations were done with classic refractors of up to 4” aperture, and included night vision enhancement. The thread fired my interest in OB associations, and I admire Allan’s commitment to making detailed observations with small telescopes. Also, other experienced observers chimed in with additional information. It’s one of the best threads I’ve ever encountered on CN.

Allan also published an overview of his Classic Rich Field project in Nightfall, the Journal of the Deep-Sky Section of the Astronomical Society of Southern Africa. It just came out this summer, and it’s a free download at this link (17 Mb).

What I did not know until recently is that he has a bunch of other threads going, including “Classic Messier“, “Classic Best NGC“, “Classic Planet Observation“, and “Classic Moon“. Turns out he also has a clearinghouse page with links to all of them, which is here. Go read and be inspired.

Scott Harrington’s DSOs for Small Telescopes, Binoculars, and Naked Eyes

From the wonderfully useful site Adventures in Deep Space, check out these thoroughly awesome observing lists:

100+ Planetary Nebulae Visible with Small Telescopes & Binoculars, by Scott Harrington

250+ Deep-Sky Objects Visible with 7×35 Binoculars and the Naked Eye, by Scott Harrington

Bob King’s Night Sky with the Naked Eye

I spend a good chunk of every dark sky observing session just looking around, with no instruments. So I was excited when this book came out, I got a copy, and I love it. Of course, that was all four years ago, and you’re just hearing about it now because I’m kind of a lousy blogger. But there you go. Here’s the Amazon link.

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Observing Report: SkyScanning on Mount Baldy

September 5, 2020

Backstory: from NEOWISE to Jupiter to the stars

Since I write a monthly column for Sky & Telescope, I can’t ever just quit observing (this is a good thing). But I do go through dry spells where I only observe enough to feed the column. Other times my observing ticks up, usually when something comes along to prod me into getting out more. In July it was comet NEOWISE, then last month it was seeing Jupiter and Saturn so big and bright in the southern sky, with Mars coming along close to midnight. At the same time, I was doing some unrelated sorting and straightening in our home office and I rediscovered some unfinished logbooks for observing projects–the Binocular Double Star and Galileo program logbooks for the Astronomical League (available here), and logbooks I put together for myself for Stephen James O’Meara’s Hidden Treasures and Secret Deep. One of the Galileo club projects is to observe Jupiter’s moons for 17 nights in a row, and use those observations to determine the orbits of the moons. This is a good time of year for such a survey, because we’re pretty much guaranteed 17 clear nights in a row.

For the Galileo club, there is no limit on aperture but there is on magnification: to count, observations have to be made at 20x or lower. My longest focal length eyepiece is the 32mm Plossl, so any scope with a focal length over 640mm is out. In practice that only disqualified the XT10 dob (1200mm) and Apex 127 Mak (1540mm). The C80ED just slipped in–with a focal length of 60mm, it gives 18.75x with the 32mm EP. In the end I made a few of the observations with that scope, and a few more with the little SV50 that I mounted side-saddle with the Apex 127, but my most-used scope for the Galilean moon survey was my serendipitously-purchased and much-modified SkyScanner 100. I didn’t have time for a big observing session every night, but I could grab the SkyScanner with one hand, plop it on the hood of the truck, and be on target in about as much time as it took to compose this sentence.

During this period I was also periodically faffing about with London’s 60mm Meade refractor, and also with the 80mm “reflactor” I nicknamed the Ferret (see this post). I need to do a full writeup on that scope soon. But the point for now is that over a span of about three weeks, I was using most of the scopes in my arsenal:

  • Apex 127 for high-power views of Jupiter, Saturn, the Moon, and Mars
  • C80ED, for the same targets
  • London’s 60mm Meade, for the same targets
  • SkyScanner, for low-power observations of Jupiter’s moons
  • SV50, for the same
  • the Ferret, for evaluation purposes

About the only scopes I didn’t haul out during this period were the XT10, Bresser AR102s, and Tasco/Vixen 9VR. The upshot is that I had the opportunity to compare the SkyScanner to a lot of other small scopes, of varying designs, apertures, and focal lengths. I kept coming back to the same thoughts:

  1. The SkyScanner pulls down a lot of light; 4″ is a formidable aperture for a 6-lb scope (with mount!) that is easily carried in one hand.
  2. The focal length is short, so magnification is limited, but the images are bright and the field of view is wide.
  3. With the collimation dialed in, and at the low magnifications I was using, the images were very sharp and contrasty.

Then I realized a few more things:

  1. These are all the same attributes I love about the Bresser AR102s–which is, for its aperture, the finest deep-sky scope I’ve ever owned–but in an even smaller package, capable of even wider fields.
  2. In four years of owning the SkyScanner, I’d mostly used it for quick peeks at bright stuff from the driveway, and I’d barely used it on the deep sky at all.
  3. Despite all my yapping about small scopes (exhibits A, B, C, and D, for starters), I’d never done a serious observing program with one.

Clearly, I needed to get the SkyScanner out to a dark site and spend some time chasing DSOs. A Messier survey seemed like just the ticket, to get a handle on the capabilities of the scope, and to ease myself back into deep-sky work. Also, although I look at the best-and-brightest Messiers almost every time I’m out, the lion’s share of my Messier observations have been made in the spring, in preparation for or during a Messier Marathon. It would be nice to reacquaint myself with those objects at a different time of year.

A Perfectly Imperfect Start

Normally for deep-sky work I’d head to the desert, someplace like Anza-Borrego Desert State Park or Afton Canyon if I wanted super-dark skies, or Owl Canyon or the Salton Sea for convenient, decently-dark skies. But it’s hotter than two hells in SoCal right now–out at Owl Canyon this weekend, it’s still going to be 86F at midnight. Even here on Mount Baldy the nighttime low was supposed to be 75F, but that’s at least doable, and I’ve done plenty of observing from Cow Canyon Saddle and Glendora Ridge Road. It would work. Except that when I got up there last night, Glendora Ridge Road was closed because of the extreme fire danger, because of the extreme heat and the fact that it’s the middle of our dry season.

Oh well, no worries, I know of a couple of turnouts that are deep enough that I could set up 50-100 feet from the road, and put the scope on the far side of the truck to block most of the headlights. So I went to one of those and got all set up: SkyScanner on a tripod, binoculars to hand, charts and logbook on a folding table, plenty of water and snacks.

Then the moon came up.

Normally for deep-sky work I’d head out near the dark of the moon, but the fact is, I was impatient. So I decided to go out last night, knowing that the waning gibbous moon would rise at some point, but figuring that between the transparent mountain air, local hilltops and ridgelines to put me in shadow, and the fact that moon is waning, I’d be okay. Then I spent too much time messing around at the house, and I didn’t actually get set up on the mountain until 10:15, about 3 hours after sunset and a full hour and a half after astronomical twilight. The moon was already lighting up the ridgeline to the west, and before midnight it had crested the ridge to the east, and was falling directly on me. I could almost read the charts without a flashlight.

I had to laugh, because my very first observing session using a SkyScanner was with Doug Rennie back in 2012, when we’d been out 3 nights after the full moon. It was the same this time, almost to the minute: the full moon had been at 10:22 PM on September 1. But I was also encouraged, because Doug and I had a great time then chasing DSOs under a bright sky with a small scope. Would I be able to replicate that success?

Aside: Training the Eye vs Stressing Over Gear

Also, in general, my observing philosophy is “go for it”. Amateur astronomers can be a neurotic lot, agonizing over setups and field of view and light throughput and a thousand mechanical and behavioral minutiae to squeeze every last photon out of every last carefully-deployed dollar of gear–I know, because that’s what about half the posts on this blog are about. But there is also freedom in setting all of that aside, being grateful for optics that Galileo or Messier would have eaten their own legs off to get hold of, and just looking. So the conditions are imperfect. So your optics are suboptimal, cheap or small or chintzy or some combination of the above. What’s better, observing, or not observing? The astronomy police aren’t going to come lock you up for doing it wrong. Some of my most memorable observing sessions have happened with suboptimal gear under suboptimal conditions, which raises the question of what “suboptimal” even means in this case. Did you see stuff in the sky? Did you have fun, or find the experience educational or rewarding, or get to share it with another human being? Good enough.

Before someone misunderstands my point, I’m not saying just run out and buy any old things. As I’ve said about choosing vs using binoculars, there are loads of things you can and should consider when you purchase an observing instrument. But if you’re going out to observe, use whatever you have to hand. Don’t worry about its quality, get out there under the stars and let it show you what it can do.

A couple of quotes come to mind here. One is something I read some time ago on Cloudy Nights. I thought I had it saved somewhere, but to my immense irritation, I can’t find it at the moment, so I don’t know who said it or when. Nevertheless, it went something like this:

“I realized that most serious observers go after objects that are near the limits of their instruments. Even for a small telescope, that is hundreds or thousands of objects. And I’ve been happily pursuing small-scope observing ever since.”

EDIT: Of course, within about an hour of posting this, I’d found the quote–in one of my own previous posts! The post of mine is “Big fish with light tackle“, the quote was from CN user blb, originally posted here, and here’s what he actually wrote, quoted at a bit more length:

“No matter what size telescope you use, it seems that you are looking at objects that are on the limits of what can be seen with that size scope. Once I realized this and read, some years ago now, what Jay Reynolds Freeman had to say about his observations, I came to realize there were way more objects to be seen in a small telescope than I would probably see in my lifetime. Having come to this realization I made a list of the galaxies that could be seen in a small scope. I included all the Messier, Caldwell, Herschel 400, those listed in Stephen O’Meara’s books, and a few more that others said were possible to see and you know what? Given dark skies and good dark adaption using averted vision, tube tapping, heavy breathing and all the tricks a good deep sky observer uses, there were well over 600 galaxies that could be seen. Now that does not include globular clusters, open clusters, planetary nebula, bright nebula, reflection nebula and dark nebula. What about double stars? There are over 10,000 that can be seen in a 4-inch telescope, most of which are seldom observed. Now add to all that the ease of portability, setup, and use, you see why I have used primarily these two small telescopes the past couple of years.”

The other is from Stephen James O’Meara’s introduction to Walter Scott Houston’s Deep Sky Wonders:

“Scotty had a light touch and avoided being distracted by technical details. You don’t find any invidious comparisons of different telescope or eyepiece brands in his writing or much about the nitty-gritty of equipment at all, because Scotty knew that the most important piece of equipment was the eye, and its training the most important activity; all else was trivial by comparison. Time wasted arguing the virtues of one eyepiece over another was time not spent honing your observing skills.”

Heck yeah. Let’s go misuse a telescope!

The SkyScanner Messier Survey, Part 1

So there I was, set up on a dusty highway turnout, bathed in moonlight, about to go chase Messier objects with a scope that actually would fit in a breadbox. I didn’t want to mess with my whole eyepiece case so I’d just taken five:

  1. a 32mm Plossl for max field of view;
  2. a 28mm RKE because it’s my favorite;
  3. a 17mm Kellner I found in a box of miscellaneous astro-junk and have been evaluating;
  4. a 12mm Plossl that is wonderfully clear and sharp;
  5. and a Celestron 8-24mm zoom.

However, very quickly after I started observing I narrowed down to just two: the 28mm RKE, which gives 14.3x and a true field of just over 3 degrees, and the 12mm Plossl, for 33x and about 1.6 degrees. I don’t have a magnifying finder for this scope, and the moon was wiping out a lot of the dimmer stars, so my usual program was to use a green laser pointer to get the scope on a bright star, then star-hop from there.

And now, finally, on to my observations, mostly verbatim from my logbook. Times are indicated here and there, whenever I remembered to check. Scorpius and Sagittarius were still up when I started, but squarely in the light dome over the Inland Empire. I’d scanned them with 7×50 binos and seen nothing, and I didn’t try with the scope. Instead, I turned to the west, to catch some things before they set.

M13 – an easy catch at 14x, didn’t try at 33x. (10:45 PM)

M92 – same.

M57 – visible in averted vision at 12x with 32mm Plossl, a bit easier at 14x in 28mm RKE, easy and with a hint of donut-osity at 33x with 12mm Plossl.

M56 – visible at 14x, better at 33x.

M71 – barely there at 33x. Suspected in 28mm RKE, though. (11:20 PM)

M27 – easy in 28mm RKE even in these skies. Need to do some comparison tests from home.

M29 – easy catch in downtown Cygnus.

M39 – very easy.

Then I got up, walked around, drank some water and some caffeine, and sat on a boulder to eat a snack. Breaks like that are important in a long session. When I got back to the scope, it was time to head north.

M52 – suffering under this moonlight. Suspected at 14x, confirmed at 33x.

M31 – MUCH reduced, basically down to just the core, but the core was easy.

M32 – suspected as a fuzzy star at 14x, confirmed at 33x.

I didn’t even try for M110, it really suffers under any light pollution, including that of the moon. Instead, I tried for M76. I got to the right field, but I could see nothing at 14x. I suspected it at 33x, barely, maybe, but not enough to count it. We’ll have a rematch under better conditions.

M103 – surprisingly easy at 14x, but still not a nice as nearby NGC 663.

Here I spent some time using the Double Cluster, Trumpler 2, and the Alpha Persei Association to star-hop to M34.

M34 – big, bright, detailed, easy, even at low magnification.

At that point I’d gotten all the easy northern ones. The Pleiades were not quite up yet, on account of a close hill to the east. Instead, I turned south.

M11 – probably the worst view of it I have ever had, but it was there, at both 14x and 33x.

M15 – dead easy at 14x, even with the moon behind me shining right into the eyepiece when I move my head.

M2 – bright, easy, maybe even easier than M15. Have I been neglecting a great glob just because it’s kind of a pain in Messier Marathon season? I repeated the star hop from M15 to M2 with the 7×50 binos and again thought that M2 was a little easier catch. Definitely going to have to spend more time with this object. (1:15 AM)

On the star-hop from Sadalsuud (Beta Aquarii) to M73 and M72, I stopped at NGC 7009, the Saturn Nebula. It was visible at 14x but I had to go up to 33x to confirm that it was non-stellar.

At 1:30 I happened to be glancing at the ridgeline to the west when I saw a very bright meteor going past Saturn, from northwest to southeast. It was a fireball, and as I watched it visibly broke up into a handful of gradually-diverging chunks that individually flamed out and went dark. It was easily the best meteor I’d seen in years.

M73 – kinda stupid, since it’s just 4 stars, but not that hard. Spotted easily at 14x, but had to go to 33x to confirm that it was non-stellar.

I tried hard to get M72. I was dead on and using every trick in the book, including cupping my hands around my observing eye to bock stray light and breathing deeply, but I could only barely suspect it at 33x, and not well enough to count it. It was way down in the murk over LA and the Inland Empire. I could see the mag 9.3 star next door, but not the mag 9.4 cluster. Sometimes visibility hinges on such tiny increments (that, and the fact that the cluster’s light is distributed across its face, leading to an even lower surface brightness).

M30 – could not see it at 14x, then it was easy at 33x, and then when I went back to 14x it was tough but doable; I just needed to know where to look.

I went after M75 and after star-hopping across literally the entire constellation of Capricornus I found that it had just set–I missed it by 2 degrees, or 8 stinkin’ minutes.

Enough chasing tough stuff in the southern sky. Taurus and Auriga were up, so…

M45 – awesome, even in these bright skies. Nicely framed at 14x.

M38 – same story as M30. Could see nothing at 14x. At 33x, the cluster was not just easy, but partially resolved, with its characteristic duck’s-foot shape. Once I knew exactly where to look, I could catch it at 14x–barely.

M36 – obvious, big, even partly resolved at 14x. Great at 33x.

M37 – faint but there at 14x, as a hazy patch. Wonderful at 33x: partially resolved in direct vision, with many more stars momentarily popping into view in averted vision.

M35 – very large. Not super-obvious at 14x, but it was there. Highly resolved and quite beautiful at 33x.

Tried for M1, could not get it at any magnification. (2:49 AM)

Spent some time looking at the Moon and Mars. Mars was a tiny bright dot at 33x, with no details visible, but I didn’t feel like getting a more powerful eyepiece. The Moon looked great. I love moon-gazing at low magnification, when the whole disk fits in the field of view with plenty of space around it. It looks like a world–which, of course, it is.

The Stingray asterism, which includes the open cluster Collinder 65, traced on chart 7 from the Beginner’s Star Atlas; the latter is a free download here.

I went back to the Pleiades for what was going to be my last look before I packed up, but then I noticed that Orion was very slowly climbing over the ridgeline to the east. I cruised along the local horizon and observed Bellatrix, the Orion OB-1a association (in the vicinity of 21, 23, and 25 Orionis), Meissa, and the Stingray asterism I wrote about in the January 2018 Binocular Highlight column. Which reminds me, I should blog about a few things: Allan Dystrup’s “Classic Rich Field” posts on Cloudy Nights (here), the Beginner’s Star Atlas (here), and about the asterisms I’ve written up for Sky & Tel (uh, in the pages of Sky & Tel).

While I was waiting for Orion’s Sword to come over the hill, I got up to walk around a bit and get some circulation going. Coming back I was startled to see a large animal move out into the moonlight just 50 feet away. It was between me and the Moon, so it was just a pool of black shadow casting a smaller black shadow on the ground, but it was big. I froze. There are bears on Mount Baldy, and mountain lions. I tensed, preparing to either run for the car or at least grab the folding chair to defend myself. I needed to know what this thing was. I reached up and flipped on my headlamp, which goes red first, then to bright white light if you keep pushing the button. The red light came on and I saw two red eyes shining right back at me. Gulp! Then the white light came on and I saw that it was just a deer. Whew! My heart was still pounding. I switched the light off to stop inconveniencing the deer. It didn’t spook, and in fact it spent a few minutes just walking around out in the open, stopping to nibble a tuft of grass or a low bush now and then. The wind had died down for a moment, and the night was so quiet that I could hear its hooves softly clattering on the rocks as it walked. I felt an utterly unexpected rush of embarrassment–not because I had gotten scared, it’s perfectly sane to be alarmed when you realize there is a large animal close to you in the dark–but because I was suddenly aware that I was on the deer’s turf. It was supposed to be there, I was the interloper. So I stayed still until it wandered off.

The sky had still been turning overhead while I watched the deer–or, more accurately, the Earth had been spinning eastward, carrying me with it–and Orion’s Sword was almost over the ridgeline. I sat down at the scope and did something I can’t remember ever having done before: I watched through the eyepiece as the Orion Nebula rose over the local horizon, at 3:20 AM. The wind had come back up, and the seeing was particularly ragged in the east. I could only get 3 members of the Trapezium at 33x. I checked and I was seeing M43 as well as M42. I tried for M78 but it was a no-go. I went back to the Belt and Sword for one last look, and shut down.

Taking Stock

I set up at 10:15 PM, started the Messier observations at 10:45, and continued in that mode for 5 hours, including breaks. During that time I logged an even 25 Messier objects. I got to the right field for five others–M76, M72, M110, M1, and M78–but couldn’t see them under the conditions I had. Along the way I also observed 3 meteors, the Moon, 3 planets, 7 double stars, and 14 non-Messier DSOs, for a total of 53 objects. It was my longest observing session since the Messier Marathon in April, 2019.

The SkyScanner rocked. When I couldn’t see certain objects, I knew it was the skies, not the scope. Many objects looked fantastic despite the moonlight–the open clusters M34, M35, M37, and M45 stand out. I had never before caught the dwarf galaxy M32 in such bright conditions. Yeah, the moon was a pain, but that just meant I had to push my observing skills a little, and it made the tough catches that much sweeter. I found a few new things to write about for Sky & Tel, saw a fantastic meteor, and had a close encounter with the local wildlife. All in all, a wonderful observing session, good for the mind and the soul.

I’m going to finish the Messier survey with the SkyScanner. It’s a splendid Messier hunter–easy to use, wide field of view, and sharp enough to dial in on the tricky ones. It’s one of my favorite scopes, and easily the one I’ve recommended the most times to people thinking about a first scope. For 100 bucks you get a capable, convenient instrument. If you hate it, at least you gave observing a fair shake, and you’re not out much (compared to other available options). If you love it, it can keep you busy for a long time–potentially for a lifetime, depending on your interests–and it’s a great grab-n-go scope if you move up to a bigger instrument. It’s not perfect–I hacked the heck out of mine to make it work like I wanted it to–but I think it is probably unbeatable in terms of capability per dollar. I’m glad circumstances conspired to make me finally get one, and I expect to get many more nights of enjoyment out of it.

Until next time, keep ‘Scanning!

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Scopes you can build: AstroMedia Newtonian reflector

September 4, 2020

I just realized that although I’ve built several AstroMedia kits, I’ve never given them more than a brief mention here and there on the blog. If you’re just here for the link, click here. If you want more info and pix on AstroMedia kits and what it’s like to build them, read on.

AstroMedia is a German company that makes primarily astronomy-related kits. That’s not all they do–they also have kits to build heat engines and musical instruments, and they carry meteorological and physics gadgets like Galileo’s Thermometer and Einstein’s Drinking Bird–but as their name implies, the lion’s share of their products are related to astronomy. That includes not just telescopes, but also a sextant, a handheld spectrograph, a sun movement simulator, a working orrery that includes the Sun, Mercury, Venus, Earth, and the Moon, and other things besides. But also, telescopes, including Galilean, Keplerian, and achromatic refractors, and a Newtonian reflector.

Of the AstroMedia kits that might be used for serious (or at least semi-serious) observing, the ones that stand out are the Plumber’s Telescope, shown here, and the Newtonian Telescope. I have built both. The Plumber’s Telescope is pretty cool: it includes the 40mm objective lens, lenses to make an eyepiece, cardboard mounts for the lenses, and a wooden mounting block for attaching the scope to a tripod. The tube and the eyepiece housing are made from plumbing parts, hence the name of the scope.

I built one of these for London a few years ago–here’s a photo of him using it at the 2014 All-Arizona Star Party. At this remove, I can’t remember if the scope natively accepts 1.25″ eyepieces and accessories, or if I built London’s with that capability. I put in a 45-degree correct-image diagonal to make it more intuitive for him to use. The scope focuses with a sliding drawtube, like an old-time spyglass.

I’ve thought several times about digging this scope out of storage and giving it a whirl from a dark site, but I haven’t actually gotten around to doing that. I talk a lot about small-scope observing, but lately it’s been more mid-scope observing, with the C80ED, SkyScanner 100, and Apex 127. More on that soon, probably.

The mother of all AstroMedia telescope kits is the Newtonian Telescope, shown here in an AstroMedia photo with the optional full-aperture solar filter made with Baader solar film. I built one of these a few years ago, and documented the process in photos, I just never got around to posting about it until now.

The primary mirror is spherical, and as shipped it has a diameter of 70mm and a focal length of 450mm, for a focal ratio of f/6.4. But in the assembled kit, the outer 5mm of the mirror are masked by the telescope’s front aperture and by two additional light baffles inside, which make the operational diameter 60mm, for a focal ratio of f/7.5. This is getting up into the range where spherical mirrors perform almost as well as parabolic ones, and that factor alone might explain the decision to mask the mirror down to 60mm.

I knew right out of the gate that I wanted my scope to be a little stronger than the default cardboard tube, so I got some wooden dowels and punched holes for them in the bulkheads/baffles that separate adjacent tube sections.

Here I did a test fit of the tube, without glue, to figure out how long I needed to cut the wooden reinforcing struts. You can see a page of the instruction manual at the upper left corner. I should say here that the AstroMedia instruction manuals are in English (at least from AstroMediaShop.co.uk), and they are excellent. Very detailed, with illustrations, clearly written by people who have actually built these kits firsthand and recently. In the depressing swamp of crappy telescope instruction manuals, AstroMedia a rare point of light.

Here’s the tube going together.

And the final product. You can see a bit of dowel sticking out the back of the OTA. The primary mirror is glued (or maybe double-sided taped? I can’t remember now) to a hexagonal piece of cardboard that forms the back of the OTA. That piece of cardboard can be left loose, so that fine adjustments can be made to achieve collimation. I went a step further and made a simple collimatable cell, with push-pull collimation using three bits of dowel that stick out of holes on the back of the tube. Friction of the cardboard mirror cell against the walls of the tube are enough to keep the mirror in place once it’s collimated.

Here’s a view down the hexagonal focuser drawtube. The white circle is the reflection of the primary mirror, sitting inside a slightly larger dark square that is the flat secondary mirror on its two-vane cardboard “spider”, and containing a smaller black reflection of the secondary mirror, within which is the black and blue of the case, body, and camera aperture on my old iPhone 5c, which I used to take this photo. As you can see, collimation is not bad; everything is at least roughly in alignment.

The two eyepieces can ride in little carrels on either side of the base. The kit includes 2 eyepieces, a 15mm Ramsden (30x) and a 28mm Steinheil (16x), which is a 3-element eyepiece type I was not previously familiar with. Focus is achieved by sliding the eyepieces up and down in the focuser tube. Possibly 0.965″ eyepieces would work as-is with the scope, although you’d have to be careful about their weight either pushing down the front end of the scope or deforming the tube.

How does it work? The mini-Dobsonian mount works great, as does the straight-through peep-sight finder–at least for the bright stuff that you’ll probably use this telescope to look at. Optically, it has the limitations you’d expect from an obstructed 70mm spherical mirror in a cardboard tube with plastic eyepieces. Which is to say, it’s good enough to demonstrate the principles of a Newtonian reflector, but I’ve not undertaken any serious observing projects with it. It should be good enough for a Messier survey, for someone with sufficient fortitude. For me, it was a fun project and it looks cool on the shelf, but I’m unlikely to press it into service as long as I have more convenient options available. Also, right now the kit goes for about $27 for just the telescope, and $30 for the scope plus solar filter, so you’re not risking much if this sort of thing appeals to you.

I have heard of people buying this kit just for the mirrors, and building mini-reflectors around them using wood, plastic, metal, and more exotic materials. A few years ago I found a webpage where a group of amateur astronomers in Germany all bought these kits and formed a “70mm club”, with each person building their own take on a 70mm reflector. There were some really creative designs on that page, which to my intense irritation I can no longer locate (if you know if it or find it, please let me know in the comments!). So if you’re in the market for small Newtonian optics for a STEM project or demonstration, this kit is an inexpensive way to get a decent primary and secondary mirror set, whether or not you build it as shown.

Verdict? You have to look around a bit to get a good Plossl eyepiece for the cost of this kit, which gives you a whole working telescope. I’m a big fan of people either buying cheap astro gear and taking it apart, or building their own–even if the results are ugly, as mine often are–both to understand the principles of astronomical optics better, and to demystify the process for the day when they need to take apart a scope they care about, either to clean it or repair it. Plus this one is fun and the results are pretty cool. Recommended. Here’s the general AstroMediaShop homepage (link), the one specifically on this and other telescopes (link), and the one on the package with this scope and the solar filter (link).

skyscanner-100-before-hacking

If you have built this and want a step up, or want something like this without having to build it, the Orion SkyScanner 100 is a serious piece of kit that will show you a lot for about $100. Its elder sibling, the StarBlast 4.5, is a little bigger, a little easier to use, and a little more nicely appointed. You really can’t go wrong with either one.

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Crazy scope deal: Newegg.com is closing out the Bresser Messier AR102S Comet Edition package

August 29, 2020

Yes, the awesome RFT with the strange design and incredibly long name is still around. Amazon is selling the package for $399 (link), BUT as of right now, Newegg.com has it for just $240 (link). You have to log in to see the price, which I did before making this screenshot. Considering that the tripod is actually stable with this scope, that the binoculars are actually good (don’t tell the bino snobs, but these came-with 7x50s are my favorite low-power glass!), and the eyepiece is fine as long as you don’t look at anything bright (on Saturn, it showed CA in my Maksutov, but it’s fine for deep sky), that is a cuh-ray-zee deal. The scope itself is a fine low-power, wide-field sweeper. It’s not a planetary scope, although its planetary performance can be improved with a sub-aperture mask. But for what it’s designed for–rich-field viewing of the deep sky–it’s terrific. If someone told me I had 5 minutes to grab gear for a Messier Marathon or they’d shoot me, I’d grab that scope, the 28mm RKE, a folding chair, and a water bottle, and be out the door with minutes to spare. You can find the rest of my blatherings about this scope under this tag (link).

If you have any interest in a rich-field telescope, pounce on this deal while it’s still around.

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Summer observing: planetary nebulae

August 25, 2020

Messier and Caldwell planetary nebulae, modified from the Caldwell object star chart produced by Jim Cornmell at https://commons.wikimedia.org/wiki/File:CaldwellStarChart.svg. Both the original file and this modified version are released under a Creative Commons Attribution Share-Alike license (CC BY-SA 3.0).

This all-sky chart shows the planetary nebulae from the Messier and Caldwell catalogs. Horizon lines are for southern California for the next couple of weeks. I put this together for a little observing feature I’m writing for Nightwatch, the monthly newsletter of the Pomona Valley Amateur Astronomers. I don’t know how well this map will reproduce, which is why I’m stashing a high-res copy here, so I can link to it in the newsletter feature. I will eventually post the observing feature here, too, probably sometime next week after the PVAA members have had a chance to see it in Nightwatch.

EDIT: I’m too lazy to reformat the observing feature for the blog, but I will link to it: here you go.

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Hideously belated observing report: Mercury transit on November 11, 2019

August 22, 2020

Not a ton to say about this other than that we saw it. London was home from school for Veteran’s Day. It was sunny, warm, and bright, and neither of us fancied spending a ton of time standing in the sun, so we limited ourselves to a few quick peeks rather than continuous observation.

About the only notable thing about the transit was our observing rig, which is probably the redneckest job I ever threw together. Most of my good gear was packed away at the back of the garage and I didn’t fancy digging it out, so I taped a pair of cardboard eclipse glasses over the front of the SkyScanner 100 to create a subaperture mask, taped some spare cardboard from a torn-up Amazon box over that to block all the filter-less areas, and set the whole rig on our green-waste bin. It was decidedly low-tech, but not as sketchy as it sounds–I taped everything very securely to the tube so none of it could fall off, because the risk of direct, unfiltered sunlight through a scope is nothing to joke about. Then London and I took turns shading each other’s faces so we wouldn’t be squinting against the sun while we observed.

I didn’t take any pictures, we just watched the crisp little BB of Mercury drift across the face of the sun. The “lenses” of the solar glasses are about an inch in diameter, so basically we turned the 100mm f/4 system into a 25mm f/16 system, and a light cone that long is pretty forgiving. Which reminds me, I’ve just been reading about people experiencing a pseudo-3D “marble” effect when viewing the moon through telescopes of 40mm aperture or less. I should make a 40mm aperture mask for my C80ED and see if I get that effect.

Anyway, thus ended the transits of the twenty-teens. I was fortunate to catch them all: the Venus transit on June 5, 2012 (observing report), one Mercury transit on May 9, 2016 (observing report), and this second Mercury transit on November 11, 2019. The next Mercury transits won’t be until the 2030s: November 13, 2032 (I’ll be 57), and November 7, 2039 (64). Then 2049 and 2052, 2062 and 2065, and 2078. I’ll be 103 if I make it to that last one. The next Venus transit won’t be until 2117, 142 years after my birth, so barring some kind of technological miracle I don’t reckon I’ll be seeing another. It was a privilege to see the one that I did.

Now transit season is over for a bit over a decade, so we’ll have to find other things to keep busy with. Fortunately the sky has much to offer. Stay tuned.

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Hideously belated observing report: another Messier Marathon at the Salton Sea (from April 2019)

August 16, 2020

Although you’d never know it from the complete dearth of posting from October, 2018, to last month, I neither died nor gave up stargazing. I even had some pretty cool experiences, I just didn’t summon the energy to blog about them. I’m now going to engage in some retrospective pothole-filling, starting with my 6th and most recent Messier Marathon.

Terry getting his 5″ f/8 Meade reflector set up for an evening of deep-sky observing.

Terry Nakazono had gotten in touch and we decided to make a run to the Salton Sea on the evening of Saturday, April 6, 2019. After logging over 2000 deep-sky objects with telescopes of 4.5″ and smaller, Terry had finally allowed himself to indulge and had moved up to his 5″ f/8 Meade reflector, which he had mounted on an AZ4 alt-az.

I was feeling lazy and didn’t want to dig a bunch of gear out of the back of the garage, so I brought London’s XT4.5, which is just an astoundingly comfortable and convenient scope. It normally sits near the front of the garage and these days it probably gets hauled out more than all the other scopes we own combined, just because it’s so quick and gives such good views. If London takes it with him when he moves away someday, I will definitely get one for myself. You can see it here on the homemade stand I made for it a few years ago, to get it up to a comfortable height for seated observing.

I wanted to do a Messier Marathon, but April 6 is getting right to the end of the season, so I figured I’d have some trouble with the early evening objects like M74 and M77. In the actual event, it was way worse: between the light pollution from LA, Palm Springs, and Indio, some clouds in the northwestern sky, and some trees in that direction, I missed not only M74 and M77 but also the Andromeda galaxy (M31) and its satellites M32 and M110, as well as M33. So I started the marathon six objects down out of 110, and the best I’d be able to do if everything else went smoothly was 104 Messiers. Still, I figured what the heck, I’d done my first three marathons (linked here) without getting that many, and there was no shame in ending over 100, especially if I had an enjoyable night under the stars doing it. So I went for it.

How’d it go? Other than losing those six galaxies at the start, it was my easiest marathon ever. I had the Jumbo Pocket Sky Atlas and the Year-Round Messier Marathon Field Guide, a handwritten checklist (like my other last-minute Marathon, back in 2013), my favorite 7×50 binos, and a super-convenient scope. I only used 3 eyepieces: a 32mm Plossl for max FOV, a 28mm RKE, and a 12mm Plossl, which in the XT4.5 yielded 28x, 32x, and 75x, respectively. Once I was rolling, I used the 28mm RKE almost exclusively. The reputation of this legendary eyepiece is well-earned; for the kind of relaxed, low-power deep-sky work I prefer it is unparalleled. All the gear just sort of disappeared and I was cruising through the sky, having fun and enjoying a beautiful night out under the stars.

The dark horse: London’s XT4.5. The white knight: Terry’s 5″ f/8 Meade. Photo by Terry Nakazono.

A highlight of the evening was rocking through the Virgo-Coma galaxies. Ever since my first marathon, way back in 2010, I have always tracked how long it takes me to get through this area. That first time out it took an hour and a half, but I hadn’t logged many Messiers at that point so it was my first time seeing most of them. The next year it only took me 23 minutes, and since then it’s never taken me more than 17 or 18 minutes. My record is 16 minutes, set in 2011 with binos only, and I tied that this time out with the scope.

Our chariots to the stars. Photo by Terry Nakazono.

I knocked off at 11:30 with 64 objects logged, and slept until 3:00–easily my longest and most relaxing mid-Marathon break. I was back at the scope at 3:10 to log M57, and from then on it was smooth sailing through the morning objects. I set a new record for myself in the Sagittarius/Scutum area, logging 13 objects in 6 minutes. And honestly, a good chunk of that time was just writing them down. Once you know the positions of the objects, you can basically just sweep the scope or binos across the area and count them off as you go.

How I roll in the middle of the night: atlases and logbook on a folding table, water bottle on the ground where it’s not taking up valuable real estate. Photo by Terry Nakazono.

For the last few objects, I was basically waiting for them to crawl over the eastern horizon. Here are the times for the final five:

  • M72, 4:14 AM
  • M73, 4:15
  • M2, 4:17
  • M15, 4:20
  • M30, 4:50

Yes, I got M30, the squirrelly devil, and finished with a total of 104 objects, having bagged every single Messier beyond those six starting galaxies. In the long downtime between M15 and M30 I looked in on Jupiter and Saturn, and after the Marathon was over I plinked around in the summer constellations, checking out NGC objects until about 5:20, when the sky was getting bright. Then I hit the sack and slept for another four hours.

My log, handwritten in a Field Notes 4.75″x7.5″ notebook.

Thoughts afterward? More than any previous Marathon, this one was just fun. Maybe because I knew right out of the gate that I wasn’t going to break my previous Messier Marathon total (108 objects, in 2013 and 2016), I just relaxed and had a blast cruising around the sky. I’ve done enough Messier Marathons now that the process feels familiar, and it’s nice looking in on objects that (full confession) I don’t often check in on otherwise (looking at you, M73).

The secret to sleeping in late in the desert is to park the vehicle perpendicular to the rising sun and put your cots on the west side. That’s me sacked out closest to the truck, sleeping like a baby after a successful Marathon. Photo by Terry Nakazono.

Of course, I’m still hungry to log all 110 in one night. I think I might need even darker skies and better horizons than the Salton Sea, so I am seriously considering hauling myself eastward for the All-Arizona Messier Marathon. Maybe next spring, if this damned pandemic ever subsides.

Many thanks to Terry Nakazono for being a sterling observing buddy, and for taking many of these photos and giving me permission to post them. Until next time!