Archive for the ‘SkyScanner 100’ Category

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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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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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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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Observing Report: Total solar eclipse on August 21, 2017

August 28, 2017

My parents, Norma and John (seated), and me with London and Vicki (standing), with the projected eclipse.

Long Range Planning

Since the August, 2017, eclipse first came on my radar, my plan was to see it from somewhere on the Great Plains. I had two reasons for this. One, most of my family lives in Oklahoma, and it would be simpler for them to drive up to the eclipse path than to fly to somewhere more remote. Also, on the plains you can usually see weather coming from a long way out, and fronts move in predictable ways. I figured that if clouds did spring up on eclipse day, I’d have a better chance of driving to get around them on the plains than anywhere else.

Originally I’d been thinking Kansas or Missouri, both of which border Oklahoma and would have made short drives for my relatives. But a closer look at the eclipse map this spring dissuaded me. The eclipse would only barely clip the northeastern corner of Kansas, in the relatively densely populated area around Kansas City. The path of totality painted a broad stripe across Missouri, but mostly along a line connecting Kansas City and St. Louis. I figured that area would get hammered by visitors, and the cloud forecast wasn’t as favorable as it was for points west, either.

Map by Xavier Jubier/Eclipse2017.org

Nebraska, on the other hand, looked pretty good. My maternal grandparents used to live in Imperial, in the southwest corner, and they retired just a few miles down the road to Enders. Imperial would make a convenient rendezvous point, both for any family driving up from Oklahoma, and for me, Vicki, and London flying in from California.

In one sense Imperial was not convenient: it’s a long way from any major airport. Two hundred miles from Denver, and three hundred from Lincoln. But I like long drives in the country (really, I do!), and I was happy to trade some driving at either end of the trip if it would save me traffic in the middle.

I guess now is a good time to mention that I did not want to stay on the path of totality. I figured – correctly, as it turned out – that competition for rooms would be fierce, that at least some places would be gouging visitors, and that traffic would be a problem in at least some areas. Instead, I wanted to stay an hour or two off the path of totality, preferably somewhere out of the way, where crowds would not be a problem, but I’d still have a range of possible observing spots within easy driving range. Again, Imperial was a promising choice, and in early February, I called and reserved rooms for my parents and for Vicki, London, and me at the Balcony House Bed & Breakfast (which was outstanding, by the way – it’s worth going to southwestern Nebraska just to stay there).

By now, plans were firming up. I knew that the fall gross anatomy course at WesternU would be rolling by eclipse time, and Vicki and I would need to arrange things so we’d miss as few days of lab as possible (many thanks to our department chair for the time off!). But we also wanted some time in Imperial to unwind, and to visit places important to our family history. That meant leaving on Saturday, August 19, and coming back on Tuesday, August 22. The Balcony House didn’t have any rooms on Saturday night, and in fact, nobody else in Imperial did, either. So we decided to make Saturday an easy day and only drive as far as Holyoke, Colorado. Holyoke is another old family stomping ground – Grandpa and Grandma had lived there for several years, too, and it’s where my mom grew up.

Sun funnel testing in Claremont

The Sun Funnel Rides Again

Gear! I didn’t settle on exactly what I’d be rolling with until Thursday, August 17, just two days before we were to fly. My old Sun Funnel – veteran of the annular eclipse and Venus transit of 2012 and the partial eclipse of 2014 – was in storage in the garage. There was never really any question but what it would be going along; it’s just too darned useful for showing solar events to even small groups of people. I did have to decide which scope to use with it. We’d sold London’s AstroScan, but my flock of airline-portable scopes had grown in the meantime. Strong contenders included the GalileoScope, Tasco-Vixen 9VR, and SkyScanner 100. I set up and tested the 9VR and the SkyScanner, and I ended up going with the latter scope, for several reasons:

  1. It has the most aperture of any scope I was seriously considering.
  2. It’s at least somewhat collimatable.
  3. With its open design, I wasn’t worried about it overheating.
  4. It balanced the best with the Sun Funnel mounted.

For the flights, I put the SkyScanner in the padded bag that my Apex 127 came in, and packed t-shirts and socks around it. The Sun Funnel I broke down – I put the screen material in a folder between sheets of clean paper, and I stuffed more socks in the funnel itself. I also brought along four pairs of eclipse glasses, a piece of #14 welder’s glass (previously seen here), and 10×42 Bushnell binoculars to look for solar prominences during totality.

London with his grandparents in front of the Balcony House in Imperial, Nebraska

One more piece of gear came to me on the road. Sunday morning we woke up in Holyoke, Colorado, had lunch at The Skillet (which had excellent country cooking), and then popped across the street to the Family Dollar for a few odds and ends. I’d been thinking of making a little sun-finder, like the one David DeLano detailed in this post. My SkyScanner has a DIY wooden bracket that is square to the tube, so I just needed something round that I could use to project a spot of sunlight. I ended up going with a $1 empty condiment bottle, which I already blogged about here. When we rolled into Imperial that afternoon, I unpacked all of the gear and did a test run on the sidewalk in front of the Balcony House. Everything was ready – now we just needed clear skies.

Targeting on the Fly

My initial targets for possible eclipse observing spots were the towns of Tryon and Stapleton, Nebraska, both about a half an hour north of North Platte. I picked up a Nebraska road map and highlighted possible routes from Imperial to either Tryon or Stapleton, going either north to the path of totality and then east, or vice versa. Either town would have required about 2.5 hours of driving on a regular day, and I figured it would be smart to budget for eclipse traffic. The east-then-north route to Stapleton had the following problem: it went through North Platte, and if traffic was apocalyptically bad, we might get stuck on the edge of the path of totality, or even outside of it. The north-then-east route to Tryon would get us close to the centerline first, with fewer opportunities to get stuck off the path.

Ah, but then. A few days out, and the weather apps were predicting partial clouds and possibly even rainfall for west-central Nebraska. Right up until Monday morning, North Platte, Tryon, and Stapleton all looked they might get clouded out. So Sunday the five of us – Mom, Dad, Vicki, London, and me – had a council of war. To the level of detail possible in weather prediction, the area around North Platte looked lousy, but Scottsbluff, in far western Nebraska, was supposed to have sunny skies. Between North Platte and Scottsbluff, the weather looked progressively better to the west, and worse to the east. So we changed things up: instead of turning east to Tryon or Stapleton, we’d stay on Highway 61 north out of Ogallala and shoot up to Hyannis, then turn west on Highway 2 and go as far as we needed to find clear skies. This was basically the Tryon plan with the directions reversed: go straight north to the eclipse path first, then drive east or west along the path to a promising destination.

The Drive Up

I wish I had had the time and opportunity to take pictures during the drive up from Imperial. It was beautiful. We left Imperial right after dawn, and the rising sun turned the fields to gold. Within a few miles, we could see banks of fog lying in the low spots on the landscape. And then a few miles further, the fog was lying everywhere. We started driving through fogbanks that congealed into an unbroken blanket by the time we reached Ogallala. The weather apps were still projecting clear skies to the west and, well, unclear skies to the east, so we kept going.

The fog had cleared by the time we saw our first eclipse-watchers, at the fairgrounds in Arthur. There were hundreds of people in RVs, tents, cars, and trucks, looking worriedly up at a sky that was completely socked in with clouds. We kept going, and saw a few hundred more scattered along the side of the road as we approached the center line. About this point we hit what I can barely bring myself to describe as ‘traffic’. At its worst, we were the 9th and 10th vehicles in a convoy of 13, but the convoy was rolling along at a steady 62 or 63 miles per hour, which was fine and certainly not worth the risk of trying to pass someone on a two-lane road in the Nebraska sandhills. The hills themselves were liberally spangled with wild sunflowers. From a distance, they looked like they’d been dusted with pollen. Everywhere we went the landscape was green.

Alliance

From a purely eclipse-viewing perspective, I would have been happy with any of the towns on Highway 2 west of Hyannis. Sure, they were a few miles off of centerline, but the difference in the duration of totality would have been trivial. And I figured we’d miss the big crowds expected at Alliance. But this plan had one fatal flaw, which I did not anticipate: a complete absence of public restrooms west of Hyannis. If I’d been by myself, I might have just pulled over anywhere and, er, recharged the water table as needed, but that’s a less attractive option to a group that includes two women and two senior citizens. Actually, there may have been a public restroom in Lakeside, but we had no chance to find out, as there was a big train blocking the road into town when we came by. So we headed on into Alliance and braced for the worst.

Our setup at the Western Nebraska Community College shindig. The forest of telephone poles in the background is where line repair people train.

The worst turned out to be not that bad, actually. We drove past a big group assembled on a grassy field on the east edge of town, and on to the first gas station that looked like it might have restrooms. By the time we’d all had a biology break, it was almost time for the eclipse to start. We decided to head back out to the east edge of town and see if the group on the grass still had some parking spots. This turned out to be an excellent choice. The parking was organized by the Western Nebraska Community College, which had free porta-potties and eclipse gear for sale. We ended up next to a family from Denver that we had met in line at the gas station. They all had eclipse glasses but no other optics, so I set up the Sun Funnel so they could watch with us, and they returned the favor by taking pictures of our party.

The Eclipse

As soon as we had the cars parked, I was busy setting up the Sun Funnel, while everyone else got folding chairs set up and got their eclipse glasses on. I got the photo above, my first shot of the eclipse, at 10:45 AM.

There was a wind out of the north that kept threatening to snatch our hats away, and it was flirting with blowing the scope over. I can’t remember ever setting up the Manfrotto tripod for low use, with the legs spread almost straight sideways, but I remembered from the documentation that doing so was possible. That fixed the stability issues with the scope, and from that point on, all we had to do was re-aim it every few minutes (I’d already made this switch in the family shot above – that shot is out of order in terms of eclipse phases). As I mentioned in a previous post, not only was the dollar store mustard bottle sun finder cheap and effective, but I could see the projected dot through the translucent walls of the bottle so I didn’t have to get my head behind or underneath it to aim the scope – handy when the sun was almost directly overhead.

A labeled shot from the end of the eclipse, when all six of the big sunspots were visible, with the Earth added for scale. All of the other crud on the image is dirt and bits of grass – that’s what happens when gear is left out in the wind in a grassy field for three hours.

There were half a dozen nice sunspots, and it was fun to watch the moon overtake them. A lot of the people who stopped by to look at the sun funnel weren’t familiar with sunspots, so I gave them the quick spiel: giant magnetic storms on the sun, with the biggest that we could see then being about the same size as planet Earth.

About halfway between first contact and totality, the north wind started pushing clouds across the sky, which you can see in the above video. This added some definite suspense to the proceedings, especially when, about 5 minutes before the start of totality, a huge “dreadnought class” cloud came over. I think everyone on the field was on pins and needles – we could still see the sun, as the next photo demonstrates, but it wasn’t what you’d call a great view.

Fortunately the cloud moved out of the way right at the start of totality. And I mean precisely then. Below is a shot from just a couple of seconds before, with the diamond ring effect haloed by the tail-end wisps of cloud. Those wisps moved out just as the moon covered the last light of the sun, and our view of totality was perfectly clear.

That photo above is my best eclipse shot. Vicki has a DSLR but I didn’t take it along. I did waste a few seconds, but only a few, trying to get a couple of HDR shots with my iPhone, but they didn’t really come out. I had read plenty of horror stories of people who basically missed their first eclipse messing around with cameras, so I resolved long ago that if I was lucky enough to have clear skies for totality, I’d try to spend them looking, not shooting.

For the most part, the partial phases of the eclipse were familiar to me from the 2012 and 2014 eclipses. Totality was a whole ‘nuther beast. This was my first total eclipse, and even though I had read a lot of eyewitness reports and seen some videos of other total eclipses, several things surprised me:

  1. Neither of my previous eclipses had been close enough to total to produce the weirdly sharp shadows that you get on either side of totality, when the thin crescent sun acts more like a point source than a bright extended object. So I’d never seen that effect before, and neither had anyone that I was with. We had fun marveling at our shadows, but I didn’t think to get any pictures or video of them. You can see the sharp shadows starting at 1:25 in this video.
  2. It got a lot darker a lot earlier than I expected. This was especially true in the last 10 minutes before totality. It was extremely weird – before the dreadnought cloud moved in, we were all aware of standing in direct sunlight, just not much of it. It wasn’t like diffuse sunlight coming through clouds, and it wasn’t like sunset light, either. I’ve never seen anything else quite like it – which I guess is part of the reason people chase eclipses, to see things you can’t see any other way.
  3. The inner corona was a lot brighter than I expected. I couldn’t really see any of the outer corona, just a thin bright ring around the moon. It was bright white. The contrast between the blazing white of the corona and the absolute blackness of the moon made the latter even more unearthly. In Seeing in the Dark, Timothy Ferris described the moon during totality as an “awful black ball” and I can now vouch for the accuracy of that description. It doesn’t look right.
  4. Even at the midpoint of totality, the sky was brighter than I had thought it would be, and the ground was darker. We all did look up, and saw Venus, Mars, Mercury, and Regulus, but I didn’t see any other stars; the stars didn’t ‘come out’ as I had expected. In contrast, right where we were, looking around at family members and other eclipse chasers, it was dark, like being outside half an hour after sunset. And the 360-degree twilight lit the horizon all the way around in shades of orange, salmon, pink, and violet. In general, the terrestrial effects of the eclipse were more pronounced and arresting that what was going on in the sky – with the undeniable exception of that awful black ball.
  5. I assume that the atmospheric effects on either side of totality are symmetrical – that the weird light I mentioned above in point 2 extends just as far after totality as before, and that the 360-degree twilight extends just as far before totality as after. But that’s not how I perceived them. I noticed the oddly thin light before totality, and after totality had ended I was surprised at how long the sunset effect persisted. The above photo is from a minute and a half after the end of totality, looking north-northeast, about 90 degrees off the path of the shadow, and the twilight effect is still visible in the distance.

After Totality

Totality was a rush. In the aftermath we sat around talking happily about how amazing it had been, and watching on the sun funnel as the moon gradually uncovered the sun. London and I made pinhole projections – his is above, mine below.

We also wandered around until we found a cottonwood that was projecting crescent suns on the street. Here’s a photo:

And a video – this worked out better than expected, because the wind was blowing the leaves and branches around and making the crescent suns flicker, like sunlight glinting off moving water. Shame I didn’t think to turn the phone sideways, but I’d just had my mind blown, so I’m giving myself a pass.

All too soon it was winding down. The telescope and sun funnel had been the first things set up when we rolled in, and they were the last things put away when we left. Here’s my last shot, from 1:16 PM:

Ironically, after all the gloomy predictions, traffic was worse getting away from the eclipse than it had been getting to it. I’d hoped that maybe we could head south out of Alliance and fast-track it back to Ogallala on Highway 26, but that way was jammed up. So we went back the way we came. On the drive home we were the 5th and 6th vehicles in a train of 17, and we had to settle for a bit under 60 mph, but we still made it back in good time. There was another train blocking the access into Lakeside, so I still don’t know if the town has a public restroom.

The trip had one neat little coda. On the flight home, London had the window seat, and he spotted the young crescent moon, back in the evening sky after its big adventure. I passed him my phone, and he got some great shots. Here’s the best:

What now?

There will be other solar eclipses between now and the next “Great American Eclipse” of 2024, but most of them will happen in other parts of the world, and the chances that I’ll have the opportunity to go see them are slim. Here are the upcoming eclipses and transits that I am hoping to observe in the next decade – as always, assuming the skies cooperate:

  • January 31, 2018 – total lunar eclipse
  • January 21, 2019 – total lunar eclipse
  • November 11, 2019 – transit of Mercury
  • May 26, 2021 – total lunar eclipse
  • May 16, 2022 – total lunar eclipse
  • November 8, 2022 – total lunar eclipse
  • October 14, 2023 – annular solar eclipse
  • April 8, 2024 – total solar eclipse
  • March 14, 2025 – total lunar eclipse
  • March 3, 2026 – total lunar eclipse

That’s a pretty good lineup, I think. For more details on all of these events, see MrEclipse.com.

In sum, the eclipse was awesome, in every sense of the word. I get now why people become eclipse chasers. I’m not quite to the point where I can afford to go jetting around the world to catch every single one, but I will make it to every future eclipse that I can. If you ever get a chance to stand in the path of totality, go.

UPDATE 29 August: Mike’s comment below about Cthulhu reminded me that I needed to post another picture. After I put the diamond ring photo on Facebook, my friend Jarrod posted this modified version, which I can’t unsee. Cower before Ecl, the Dragon of Totality:

Eclipse dragon

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Why and how to make a sub-aperture mask for a refractor

February 11, 2017

60mm-aperture-mask-6-comet-edition-close-up

Here’s the Bresser Messier AR102S Comet Edition with a homemade aperture mask. I just converted the scope from a 102mm f/4.5 to a 60mm f/7.7.

“WAT!? You took a refractor, the most aperture-challenged of the three basic telescope designs, and made it even smaller?”

Yup. For several reasons.

The first and most obvious is to control chromatic aberration (CA), also known as false color. Despite the name ‘achromat’, which literally means ‘no color’, doublet refractors without extra-low dispersion (ED) glass do show some false color, because their lenses do not bring all of the colors of light to the same focus point (they’re still a LOT better than scopes with a singlet objective lens, like those used by Galileo). For dim objects like galaxies, nebulae, and most field stars, the effect is not noticeable, even in large and optically fast scopes like the AR102S Comet Edition (nickname needed). But bright objects like the moon, planets, and first magnitude stars will be surrounded by purplish halos, and may have yellowish margins. In effect, the purple and yellow-orange parts of the spectrum are forming out-of-focus images that are superimposed on the main in-focus image.

The problem is that CA gets bad fast as refractors get bigger. There are a couple of standards that are commonly used to describe the focal ratio necessary to minimize CA to acceptable levels, the Conrady standard and the Sidgwick standard. By the Conrady standard, the focal ratio must be 5 times the aperture in inches; by the less stringent Sidgwick standard, 3 times the aperture in inches is good enough. Note that the standards describe focal ratios, not focal lengths, so they go up fast with increasing aperture. Here are some apertures, focal ratios, and focal lengths required to meet the Sidgwick standard:

  • 50mm (2″) : f/6 : 300mm
  • 76mm (3″) : f/9 : 684mm
  • 102mm (4″) : f/12 : 1224mm
  • 127mm (5″) : f/15 : 1905mm
  • 152mm (6″) : f/18 : 2736mm

This, along with mounting considerations, explains why reflectors and catadioptric scopes are progressively more common past 4″ in aperture. A 6″, f/8 Newtonian will be free of false color (as are all reflectors) and has such a gently converging light cone that it is easy to collimate and to focus – it’s easy for such scopes to achieve ‘planet-killer’ status if the mirror is good. A 6″, f/8 achromat will be a beast to mount and it will show lurid false color on bright objects.

But people still make, buy, and use such scopes! Why? Horses for courses: big, fast achromats can be superb deep-sky scopes, where chromatic aberration is typically not a problem. With the fixed sizes of standard eyepieces, achieving wide true fields requires short focal lengths (not just short focal ratios), and bright images require aperture, which drives the development of large but optically fast scopes like the AR102S Comet Edition. At f/4.5, it is well into ghastly CA territory on bright targets. The other night I stayed up late to catch Jupiter, and in the AR102S the planet wouldn’t even come to a clean focus. It was just a bright ball of light inside a sea of purple. I switched over to London’s 60mm f/11 Meade refractor and Jupiter snapped into a sharp and essentially color-free focus. There was a moon emerging from behind the limb of planet, already one moon-diameter out into black space, that was completely invisible in the CA-smudged view of the AR102S.

I’m okay with that – as I noted in a previous post, observing bright solar system targets with the AR102S is deliberate misuse of the scope. When I want good planetary views, I have a 5″ Mak and a 10″ Dob that can both be pushed to 500x (assuming the atmosphere is steady enough). But their max fields of view are pathetic compared to the AR102S – about 1.1 degrees for the Mak, and a shade over 2 degrees for the Dob, versus 3.6 degrees for the refractor, which is enough to take in all of Orion’s sword at once, with space left over on either side.

Still, I’m not going to take all of my scopes out with me every time I go observing, and chances are good that at some point I’ll want to look at something bright even if my main goal for the evening was low-power sweeping with the AR102S. Under those circumstances, it’s easier to have an aperture mask shoved in my eyepiece case than to pack a second scope. Hence this project and this post.

But I’m getting ahead of myself. There are other reasons to stop down a scope besides reducing CA:

  • To reduce glare from bright objects. Mostly applies to the moon when it’s full or very gibbous.
  • To give a more aesthetically pleasing image when the seeing is bad. Opinions differ on this point. Some folks prefer to look through a larger aperture despite the increased susceptibility to bad seeing, on the grounds that in the moments when the atmosphere does settle down a bit, you’ll see more detail. I suppose it depends on whether one is in exploration mode or aesthetic observation mode.
  • To make it easier to focus. F/4.5 is a steep light cone, and it’s easy to overshoot the point of best focus. Stopping down the scope makes a shallower light cone, so it’s easier to watch the image transition from out of focus, to near focus, to in focus. I’m going to test this method of finding best focus on some close double stars.

I had done some calculations in advance to figure out what sizes of aperture masks I’d want to try out. Given that the AR102S has a fixed focal length of 459mm, here are the focal ratios at full aperture and at 10mm decrements:

  • 102mm gives 459/102 = f/4.5
  • 90mm gives 459/90 = f/5.1
  • 80mm gives 459/80 = f/5.7
  • 70mm gives 459/70 = f/6.5
  • 60mm gives 459/60 = f/7.7
  • 50mm gives 459/50 = f/9.2
  • 40mm gives 459/40 = f/11.5

3-inch-sub-aperture-mask

I didn’t want to trade away too much resolving power, so I tested the scope on the moon using cardboard masks of 76mm and 60mm, made from the light cardboard spacers from a box of wet cat food. The 76mm is shown above. Perhaps unsurprisingly, at this aperture and focal ratio (f/6) the view was still unappealingly soft. But 60mm looked good, with minimal CA. This makes sense – the working focal ratio of f/7.7 is a healthy step beyond the f/7.2 that the Sidgwick standard suggests for a 60mm aperture. Going any smaller would be trading away valuable resolution, without significantly improving the image.

60mm-aperture-mask-1-gallon-jar

The light cardboard aperture masks were fast and easy to make, but they weren’t very sturdy. To make a more permanent mask, I needed plastic, heavier cardboard, or foam-core board. So I unscrewed the dewshield from the scope and walked down to the dollar store, where I looked for food packages and storage containers that might fit. Finally on the last aisle I found this 1-gallon plastic jar. The lid slip-fit over the dewshield with just a bit of extra room, which I knew I could shim out with some sticky-back felt.

60mm-aperture-mask-2-marking

I wanted to make sure the lid would fit before I did the hard work of cutting, so I put the felt on first. This was very familiar – it seems like every other scope I get has a loose dust cover that has to be shimmed to fit correctly. I’ve been slowly chipping away at the same package of sticky-back felt since 2010. I didn’t have a compass handy, so I used a small paper ruler to make a ring of marks around concentric 60mm circle inside the lid. Then found a lid to a jar of vitamins that was exactly 60mm in diameter and used that to trace the circle neatly.

60mm-aperture-mask-3-completed-mask

I was going to cut out the aperture using hobby knife, but the plastic was too tough. So I moved up to a box knife, and then a linoleum knife. Then I said heck with it and got the Dremel. The hole I cut wasn’t perfectly circular and had rough edges to boot, so I wrapped some sandpaper around a pill bottle to make a tool for rounding out the aperture.

60mm-aperture-mask-4-comet-edition-before

Here’s the scope before…

60mm-aperture-mask-5-comet-edition-after

…and after.

Even with the aperture mask, the AR102S is not a champion scope on solar system targets. The C80ED blows it away, which makes sense – it has a 33% resolution advantage over the stopped-down AR102S, and frankly just better glass. But at least the view now is clean and not appallingly degraded. A dramatic way to see the difference is to get a good tight focus on the moon with the mask on, then quickly take it off without removing one’s eye from the eyepiece, and watch the view get a lot brighter and a lot softer at the same time.

I have a few more things I want to do. The 60mm aperture mask fits over the end of the scope so securely that it could work as a dust cover, if only I can find or make something to plug the central hole. Also, I think I am going to play with making aperture masks in other sizes, just to see what happens.

And finally, I have another 4″ scope that will be fun to make an aperture mask for. But that will be a subject for another post.
skyscanner-aperture-mask-test-fit-jar-lid

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Hacking the SkyScanner 100: six easy pieces

February 7, 2017

skyscanner-100-before-hacking

Remember this thing? It’s a lovely little scope, but I got tired of crouching over it. And it’s made out of tractable materials – rolled steel and particle board, mostly – and costs next to nothing as these things go ($100 as of this writing), so it was basically crying out for customization. I made six fixes – two on the base, two on the outside of the tube, and two on the inside of the tube. They’re all cheap, fast, and easy, hence the title of the post (with apologies to Richard Feynman!).

skyscanner-hacks-1-eyepiece-rack-and-handle

My first two mods were to the base. (1) I had a leftover eyepiece rack, which I screwed to the base in the only place and at the only angle that it would fit. It works great. My very first scope, an Orion XT6, came with an eyepiece rack like this (which has since been dropped from the base model XT6), as did my XT10, and I’ve always found them to be very convenient. It took me a long time to realize that an eyepiece rack didn’t have to be horizontal to work, especially if the eyepieces are always capped so they can’t fall out.

(2) The second mod is the wire handle on the top of the base, which I scavenged from an earthquake stabilization kit for furniture. It’s just a small woven steel wire with an eyelet at either end which is screwed into the particle board that makes up the base. When I put it on, I thought I’d cut a piece of aquarium tube to slide over it as a cushion. I still might do that at some point, but so far I haven’t needed to. The whole scope and mount only weighs 6 lbs, maybe 7 with a full eyepiece rack, and I’m never carrying the scope that far. Basically from the garage to the driveway, or from the car to a picnic table. So the wire handle has not had the opportunity to get uncomfortable yet. This was the simplest mod but may be the one that has made the most difference in terms of overall convenience. Orion should just build ’em this way, even if it bumped up the price by five bucks.

The piece of tape on the tube is covering the holes intended for mounting the dot finder. I never used it, and now the holes are in an inconvenient place. I’ll come up with a more permanent and better-looking solution than the tape, but at least it keeps dust out of the tube for now.

skyscanner-hacks-2-focuser-position-and-laser-trough

This photo shows the two mods to the outside of the tube. (3) Originally the focuser pointed straight up, with the focus knobs on the opposite side of the base arm. I wanted the focuser to face up at a comfortable angle, so I wouldn’t have to lean so far over the scope while using it. And I wanted the knobs on the same side as the base arm, so the eyepiece rack would face the user. Achieving both of those goals meant moving the scope’s dovetail bar about 135 degrees around the tube. To do that, I had to drill new holes in the tube. I used a paper wrap to get the new holes lined up with the old ones and with each other, made pilot dents using a thumbtack, then drilled them out with a cordless electric drill. It’s not a good idea to have metal filings flying around precision optics, so I removed both mirrors before drilling the holes. It’s fun to take a telescope all the way apart and put it back together, especially if it works better after you’ve done so. Everyone should try it.

(4) Once I had the dovetail moved over to the new holes, I had a couple of perfectly good holes in the tube in a convenient place, and at a convenient angle from the dovetail and the focuser. So I built a laser trough to go there. It’s an idea I got from Ken Crowder, a former PVAA member. Back in 2010 on one of my first trips to the Salton Sea, Ken had his 8-inch SCT set up with a video camera for taking integrated shots of deep sky objects. To help get on target, he had wooden bracket pretty much like the one you see above, into which he would lay his laser pointer. Lots of companies make special rings for adapting handheld laser pointers into telescope finders. But like me, Ken wanted to be able to do other stuff with his laser at a moment’s notice, like trace out constellations for newcomers, or point out especially nice things in the sky without moving his telescope. The wooden bracket lets you drop in the laser and get on target quickly, and then lift it out and use it for other things.

To fine-tune the aim, Ken would shim his with little scraps of wood and paper, and I intend to do the same if necessary. But with the SkyScanner’s 400mm focal length, a 32mm Plossl yields 12.5x and 4-degree true field of view, and even a 25mm gives 16x and a 3-degree field, so even without shimming the laser is usually good enough.

skyscanner-hacks-3-laser-trough-close-up

Here’s a close-up of the laser trough. I built it out of wood scraps and glue. The hardware store didn’t have hex-cap metric screws in the size I needed so I got machine screws and washers. I used a spade bit to cut little indentations for the hardware. The two square stringers on the bottom are to help keep the whole rig aligned with the long axis of the tube.

skyscanner-hacks-4-primary-center-spot-and-secondary-bolts

Finally, the two inside-the-tube mods. (5) I center-spotted the primary to aid in collimation. The best thing to use for this is a notebook reinforcing ring. I have a whole package of those somewhere, but I can’t find it. But I did find a package of the little round stickers of the kind you use to make price tags at garage sales, and made it into a ring with a handheld hole punch. It works great. I have doubts about its longevity, but if and when it falls off, I’ll just make another. It seriously takes less than five minutes. Most mass-produced reflectors these days ship with their primary mirrors already center-spotted, and it really helps with collimation.

(6) As explained in the last post (link), I swapped the stock Allen bolts for secondary collimation with standard hex-cap bolts that I can turn by hand and lightly tighten with a small pair of pliers.

skyscanner-hacks-5-all-ready-to-go

So how does the reborn SkyScanner work? Pretty darned well! It was already an extremely convenient and easy-to-use scope, and now it’s even moreso.

I’m not done hacking on it. As shipped, the primary mirror can’t be collimated. I read on CN about lengthening the bolt holes in the OTA that the mirror cell is screwed into, so that the mirror cell can be tilted to achieve primary collimation. I tried this and didn’t like the results. It’s very hard for me to get the mirror cell mounting bolts tightened down enough to keep the mirror cell from shifting. Especially because it’s natural to grab the back of the scope to help aim it, and in doing so I almost always shift the mirror cell relative to the OTA and subtly throw off collimation. Or not subtly – at f/4, every last arc-second of collimation matters. So I’m going to build a fully-collimatable mirror cell.

And I’m going to figure out a better way to cover those holes in the tube for the finder. And flock the inside of the tube, and make a long dewshield to keep stray light from hitting the secondary and the focuser drawtube. And probably do some other stuff I haven’t thought of yet. I’m basically going to treat this scope as a testbed for every hack I can think of. Should keep me busy for a while.

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Upgrading secondary collimation bolts on a reflector

February 5, 2017

dscn1615

Here’s a fast, cheap, and easy hack that I do to every reflector that passes through my hands. I hate messing around with hex wrenches while collimating my reflectors, so I replace the Allen bolts with standard hex-cap bolts that can be turned by hand and lightly tightened with a socket wrench or pliers.

I’ve done the mod to all three of the StarBlast 4.5s that the PVAA has placed with the Claremont Public Library – which I am responsible for servicing every couple of months – as well as to my XT10, my SkyScanner 100, London’s XT4.5, and the 5″ f/5 SkyWatcher Newt I had a few years ago. You’ll notice that so far, all of the scopes I’ve done this to have been Synta-made and Orion or SkyWatcher branded. All of the smaller ones have taken identical hardware, but I did the XT10 so long ago I don’t remember – I think it took longer and possibly larger-diameter bolts, but I could be talking crazy.

If this is something you’re interested in doing, you need to take two measurements, make a run to the hardware store, and do about five minutes of work when you get back home. Or you can get a set of Bob’s Knobs, which are much nicer and designed for no-tool use. But making your own with hex-cap bolts costs less than five bucks and gives passable results, and doesn’t stop you from picking up Bob’s Knobs later if you like.

The first thing you want to know, that you can only find out from your assembled spider/secondary mirror mount, is the length of bolt that you’ll need. The secondary holder has two parts, the hub that the spider attaches to, and the 45-degree-angled mirror holder that is usually attached to the back of the secondary mirror itself with double-sided tape. The collimation bolts engage with threads in the hub, and bear against the flat back surface of the mirror holder. The Allen bolts that the scopes ship with are much shorter than the distance from the mirror holder to the front of the hub. So collimation requires sticking a hex wrench down the hole blindly and fumbling a bit to get it seated in the socket (at least for me – if that doesn’t bother you, this post will probably not be of much use).

secondary-mirror-diagram

If you’re going to replace those little shorty Allen bolts with regular bolts, you need to know the distance from the mirror holder to the front of the hub – it’s the dimension between the dotted lines in this diagram, labeled “min. length for bolts”. Your replacement bolts need to have shafts at least this long, or their caps are going to run into the hub before they engage with the mirror holder. It doesn’t really matter how much longer they are, as long as it’s not ridiculous – you don’t want them sticking so far out of the front of the scope that they’ll catch on things or scatter light into the tube.

The second thing you need to know is the type of collimation bolt your scope has – its diameter and thread pitch. If you don’t know that, and you probably won’t the first time out, just back one (and only one!) of your Allen bolts all the way out, and take it with you to the hardware store.

metric-bolt-gauge

At the hardware store you’ll find a bolt gauge like this one. Actually you’ll probably find two, one for English hardware and one for metric. If you have a scope made in China, it probably uses metric hardware, so start there.

testing-original-bolt

Here’s a close-up of me testing one of the collimation bolts from the SkyScanner in the metric bolt gauge. As you can see, it fit the 4mm socket.

replacement-bolt-bag

I already knew from measuring the scope’s secondary that I needed bolts longer than 20mm. And here’s my part: a 4mm x 25mm (diameter x length) bolt, part #81494 at Orchard Supply and Hardware. I bought six – three for my SkyScanner 100, and three for London’s XT4.5, which I hadn’t done yet.

testing-replacement-bolt

My motto is “trust but verify”, especially before buying hardware. If unbagging a part to test it in the store makes you queasy, you can just push the end of one bolt through the bag, enough to try it on the bolt gauge. This won’t destroy the packaging should you need to put it back – buy it or leave it, you can poke the bolt back into the package and only leave a tiny hole (in this case, 4mm!).

original-allen-bolts

Here are the old bolts ready to go into the bag, which has all of the original Allen bolts from half a dozen reflectors now. I don’t know why I save them. I ‘m kind of an astro-hoarder. If anyone out there wants these, let me know and I’ll send them to you gratis.

Anyway, so far, so good. You get home, back out the Allen bolts, and replace them with the hex-cap bolts. Now, this is important: for your sanity, replace the bolts one at a time. If you screw all of the original Allen bolts out before putting in any of the replacements, your secondary is going to be flopping around uselessly. It may well rotate in place and end up not even facing the focuser drawtube. Take it from an idiot who has done this! But if you replace the bolts one at a time and get all of the replacements finger-tight, the mirror will maintain its radial orientation and may even stay in pretty good collimation through the procedure, although of course you’ll want to recheck and touch up the collimation when you’re finished.

There are loads of good sources on Newtonian collimation online so I’m not going to reinvent that particular wheel. I’ll just add a couple of tips that have made my life a lot easier. The first is to try to balance the push and pull on the three collimation bolts. In other words, if you want to screw in one bolt, back off another one first. If you only ever collimate by screwing in, you’re going to either run out of travel, jack up your mirror holder, or force it farther down the tube, depending on what the deal is with the mounting bolt (some are spring-loaded, some aren’t). When I sit down to collimate the secondary, I quickly go around to each bolt and turn it both ways, backing out first and then screwing in, to get a sense for what each bolt does.

The second tip is specific to these replacement hex-cap bolts on the Orion/Synta scopes that I own and service. Once I get the secondary collimation where I want it by tightening the bolts with my fingers, I go back around and give each one a small additional twist, maybe a sixth of a turn, with the little pliers I keep in my eyepiece box (see here). If I do this evenly to all three bolts, it doesn’t affect the collimation, and the extra bit of tightness helps the scope stay in collimation longer. That might no be needed or even helpful depending on how the mounting bolt engages the mirror holder. Play around with it and see what works for you.

Replacing these bolts was just one of half a dozen hacks I made to the SkyScanner 100. The rest will be covered in another post very soon. Until then, clear skies!

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SkyScanning in Utah – and Claremont

July 25, 2016
SkyScanner in classroom

Everyone should have one of these.

I’ve been interested in Orion’s SkyScanner 100 tabletop Dob ever since 2012, when I got to look through the SkyScanners owned by Terry Nakazono and Doug Rennie. In particular, the evening I spent stargazing with Doug up in Oregon that October is in my short list of all-time favorite observing sessions. See that observing report here, and be sure to check out Terry’s guest post on the SkyScanner 100 here.

After spending literally years contemplating the purchase, what finally tipped me into SkyScanner ownership was my own forgetfulness. On July 3 I was driving to Utah to spend 10 days hunting dinosaurs with friends and colleagues. I knew I’d want some dark-sky time so I packed my C80ED, eyepiece case, sky atlas, and binoculars. About the time I hit Barstow – just too far to turn around and go back – I realized that I’d forgotten to pack a mount and tripod. So my choices were to roll with binos only, or come up with Plan B on the fly.

The number of dedicated telescope stores on the direct route between Barstow and Moab continues to hover near zero. However, I was already planning to pass through Flagstaff, which has the Lowell Observatory, which has a gift shop. I called ahead: did they have any telescopes in stock? Why, yes, the Orion XT8 and SkyScanner 100, and both were 10% off as part of a holiday weekend promo. Not long after, I had a SkyScanner in the back seat of the car and a song in my heart.

Matt with SkyScanner 100 at July 2016 PVAA meeting

Demonstrating how the SkyScanner can ride on any tripod with a 1/4 or 3/8 bolt.

I spent that first night in Bluff, Utah, after having driven through Monument Valley, which I’d never visited before. Bluff is truly remote – the nearest towns with more than 5000 people are Moab (5046), 100 miles north, and Kayenta, Arizona (5189), 68 miles southwest. So the skies are inky dark. I rolled in pretty late and I really needed to get some rack, but there was zero chance that I was going to pass up first light for the SkyScanner under those jet-black southern Utah skies. I drove about five miles outside of town and pulled over on a dirt road.

The sky was just incredible, even better than out on Santa Cruz Island back in June. Again, the Milky Way looked like an astrophoto and the Messiers in Scorpio, Scutum, and Sagittarius were almost all naked-eye visible (minus a few of the minor globs). I did look at a handful of things with the SkyScanner, and they all looked fine, but honestly I spent more time with my 10×42 binos and even more time than that just staring around with my naked eyes. In skies like that, a telescope can almost be a distraction.

Still, I’m glad I got that first light session in on the evening of the 3rd, because opportunities would be thin for a while. I did set up the scope on the 4th of July, on the trunk of the car in the driveway of my friends’ place in Moab, and we looked at a few things, but everyone was pretty pooped after a day of hunting dinosaurs and partying so we didn’t push very late. And after that, the sky was at least partly cloudy for most of a week.

Finally on the evening of July 10th we got nice, clear skies. I drove out southeast of Moab on the La Sal Loop Road with a couple of new friends and we spent a very pleasant couple of hours rocking through the best and brightest. The SkyScanner performed like a champ.

Howard Karl and Matt at July 2016 PVAA meeting

Karl Rijkse (center) shows his heirloom German binoculars to Howard Maculsay (left) and me.

I’ve only had it out a couple of times since betting back to Claremont, both times for quick peeks. As a grab-n-go scope it is, as far as I’m concerned, unparalleled. With an assembled weight of just over 6 lbs, it is the definition of a one-hander. The tabletop tripod works great, very smooth, and the rubber feet provide a good grip even on the precarious edge of a sloping car hood. And it goes on my Manfrotto tripod (3.5 lbs) for a 10-pound setup that’s perfect for a long session seated or standing.

As you can see from the photos (kindly provided by Terry Nakazono), I took the SkyScanner to last Friday night’s meeting of the Pomona Valley Amateur Astronomers, where it drew a lot of interest. I was going to set up the scope outside after the meeting so we could all have a look at Saturn, but the night sky was almost completely blocked out by smoke from the wildfires and the air quality was terrible, so we packed it in. I think I’ll get in the habit of taking the scope to meetings so we can do a little observing after – it’s always seemed to me that an astronomy club should have at least one working scope at each meeting.

Here’s my number one thought regarding the SkyScanner 100: how extremely stupid of me not to have gotten one sooner. If you’re interested in this scope and you’re on the fence, just do it. Heck, if you’re shopping for a big scope and you’re not sure what you want, get a SkyScanner to keep you busy in the meantime. It’s an insane amount of scope – and mount – for a little over a hundred bucks.

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Observing Report: SkyScanning in Oregon

October 2, 2012

I was up in Oregon last week to visit my university’s second campus in Lebanon. It was a kill-many-birds-with-one-stone type trip: in addition to day-job work in Lebanon on the weekdays, I got in a productive meeting about a joint project with a paleontological colleague who lives nearby, and–the point of this post–last Wednesday night I got to go stargazing with frequent commenter Doug Rennie.

Doug lives up by Portland and I was staying in Albany, so we needed someplace in between with reasonably dark skies. We settled on Baskett Slough Wildlife Refuge, just north of Dallas, OR. We met in Dallas for dinner and then drove out to the slough.

I had along a new-ish pair of Nikon Action 10×50 binoculars that I picked up this summer and haven’t used much. Doug brought his Celestron SkyMaster 15x70s–the same model I have and love–and his Orion SkyScanner 100 tabletop telescope.

Neither of us really knew what to expect in terms of sky quality. The waxing gibbous moon was only three days shy of full, and I was seriously concerned that we’d get “mooned out” and not be able to observe anything in the deep sky.

This brings up the interesting question of how much moonlight it takes to significantly degrade the night sky. I’ll write a full post about it someday, but for now it is enough to note that the brightness of the moon increases exponentially on the run up to opposition (full moon), and decreases exponentially after full moon. For explanations of why that is, check out this graph and this tutorial and read up on opposition surge and heiligenschein. The upshot is that three days shy of full the moon is only perhaps a quarter as bright as it is at full moon, and happily we were able to see quite a bit.

I didn’t know that when we started out, though, but I knew that we wouldn’t see anything if we didn’t try. Ursa Major was opposite the moon, getting closer to the horizon, and with it some of the best and brightest galaxies in the sky. I spent a few minutes faffing around and managed to get M81 in the field of view. It was dim, but it was there, and our observing run was underway.

Some hazy clouds were skirting the northern horizon, and I was worried they might come south and ruin things for us. Also, after the frustrating chase and unimpressive view of M81 we needed a win, so our next target was the Double Cluster, NGC 869 and 884. They were spectacular–two brilliant knots of stars in the rich Milky Way starfields of northern Perseus.

After that we hit some other summer and fall “best of” objects, including the Andromeda galaxy (M31), the Great Glob in Hercules (M13), the Ring Nebula (M57), and the Dumbbell Nebula (M27). Next to M31 we caught the brighter and more compact of its two Messier satellite galaxies, M32. I don’t know if M110 would have been visible or not. It’s a tougher catch, especially under less-than-perfect skies, and I didn’t waste any time looking for it.

M13 was an easy catch, and we kept running up the magnification to see if we could get it to resolve at all. Doug’s 6mm Expanse yielded 67x and, we thought, some tantalizing hints of detail. We Barlowed it up to 133x and the cluster took on the slightly grainy texture that is often the most resolution one can get in a small scope. We also tried lots of magnifications on the two planetary nebula, M57 and M27. We could only glimpse in averted vision the slightly darker center that makes the Ring a ring, and the Dumbbell showed the barest hint of its bilobed structure.

After that we turned back north and plied the starry Milky Way between Cassiopeia and Perseus. Cassiopeia is just lousy with asterisms and open clusters; the only ones we bothered to identify were M103 and nearby NGC 663, which is bigger and brighter.

A highlight of the evening was sweeping the Alpha Persei Association with binoculars. It’s really seen best this way–very few telescopes have a wide enough field of  view to show more than a small part of it. I once read a description of this big, close cluster–variously catalogued as Melotte 20 and Collinder 39–as a “vast wonderland of far-flung suns”, and I can’t look at it without those words coming to mind.

Since Perseus was now a good way up the sky I thought it would be worthwhile to track down the open cluster M34. I’m glad we did. When Doug looked at it he said, “I know this cluster–I’ve drawn it!” And he had–his sketchbook recorded the fingerprint-specific arrangement of stars that make up the cluster. I was most impressed by this–by the drawing and his visual memory both.

At this point we were winding down a bit and just scanning around with binos, taking things as they came. Halfway down the western sky I found the brilliant blue-white double star 16/17 Draconis. By this point Doug’s green laser pointer was fading a bit from cold and overuse, but with some yammering and gesticulating on my part–and much patience and good humor on his–we were able to get both pair of binos on target. That really is a gorgeous double, and just wide enough to be clearly split in low-power binoculars. I recommend it.

Our last stop of the night was the Pleiades, which had just climbed over the northeastern horizon. They were stunning, as always. That gave us a total of nine Messier objects, three non-Messier NGCs (663, 869, and 884), another big open cluster (the Alpha Persei Cluster), and a double star. So, 14 objects in all, which is pretty good for a two-hour session under any conditions.

Using the SkyScanner was a revelation. I had taken a few brief peeks through Terry Nakazono’s SkyScanner on our Baldy runs, and been impressed, but I’d never gotten to just pick one up and freewheel. And “freewheel” is a pretty good description of what we were doing. The scope is light enough that you don’t think twice about just picking up one-handed and moving it wherever you need it. At the same time, four inches is a lot of aperture, and I was consistently impressed by how much the little scope could do, both in terms of light-grasp and resolution. Doug must have collimated it to within an inch of its life, because the image was still good at 133x–a real achievement in any small, fast Newtonian. Finally, I didn’t notice any issues with the focuser. This is one of my pet peeves. Fast scopes have steep light cones and it takes a precise focuser to consistently hit focus without going past in either direction. One of the things that drove me crazy about the Celestron FirstScope was the lousy focuser, which consistently overshot focus. So when I say the focuser on the SkyScanner didn’t draw attention to itself, that’s a good thing. I’m sure that like all consumer scopes there’s some sample-to-sample variation with the SkyScanner, and Doug’s might be an unusually fine example, but so far both of the SkyScanners I’ve gotten to use have impressed me. I think I’ll get one for the Suburban Messier Project, which is on hold until it cools off some–it was 107 here today. In October!

Oh, and speaking of the Suburban Messier Project, I was most impressed by the quality of Doug’s sketches, and by the fact that, having sketched something once, he could recognize it at the eyepiece later without knowing in advance what it was. I’d like to have that level of familiarity with these objects, and I intend to get it–by sketching them. Stay tuned.

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Guest post: A few thoughts about the Orion SkyScanner and other scopes, including the Bushnell Ares 5

July 8, 2012

Here’s the first guest post by frequent commenter and dedicated deep-sky observer Terry Nakazono. Actually “dedicated” is an appalling understatement, since Terry regularly challenges himself and his scopes by (1) observing faint deep-sky objects, mostly galaxies, (2) with small scopes he can carry on public transportation and by foot, (3) from light-polluted skies in and around Los Angeles. I’ve been looking forward to reading about Terry’s scopes and his observing techniques, so this guest post is most welcome–hopefully there will be more to follow.

I’ve been using the Orion SkyScanner the past 2 years for nearly all of my deep-sky observing needs because it’s so easy to transport and set up – crucial if you rely on public transport and your own two feet to get to darker sky sites. For a package weighing in at 6.2 lbs with scope and mount combined, 100mm of mirror is a lot of aperture.

Both scope and mount fits snugly in this Adidas Schmidt backpack. All that’s needed is a tripod to attach the mount to, and a solid Manfrotto weighing in at only 4.5 lbs. (but with a 15.5 lb. weight load capacity) provides a strong, stable support.

Factor in the eyepieces, star charts and other accessories, and you’re only transporting about 12-13 lbs. of equipment on your body. By comparison, the Orion StarBlast 4.5 weighs 13 lbs, while the Orion SkyQuest XT4.5 is 17.6 lbs. Both cost about twice as much ($199.99 and $239.99, respectively) as the SkyScanner ($109.99) and both add only 14mm of additional aperture to the mirror. As Joe Roberts says, you will not likely find a scope that will show more for the cost.

For deep-sky work, superb optics isn’t as critical compared to planetary and double star work, so a 100mm Newtonian reflector works well (for me). Despite not having a collimatable primary mirror, collimation can be achieved by center spotting the primary mirror and adjusting the tilt on the secondary with the help of a collimation cap, significantly improving the views of the planets and double stars as well as deep-sky objects.

Here, you can just see the notebook reinforcement ring I put on the center of the primary mirror; the secondary mirror is collimated by adjusting the three allen screws surrounding the main screw in the center of the secondary holder with an allen-head screwdriver.

Having said all that, I’m no longer wedded to the SkyScanner as my sole dark-sky instrument.

I now have an Orion shoulder bag that I can carry my Orion VersaGo II mount and Bushnell Ares 5 in.

I also have a Vixen Mini-Porta mount which will support my Celestron C90 Maksutov-Cassegrain (C90Mak, top) and Orion ShortTube 80-A (ST80A, bottom) telescopes. I just ordered a smaller Orion shoulder bag that will carry the aforementioned mount and one of these two scopes. These Orion bags are ergonomically well-designed and make it easy to carry both scope and mount over your shoulder without causing major strain.

I suspect that despite their better optics, both the C90Mak and the ST80A will not allow me to see “deeper” into space (i.e. detect fainter objects) than the SkyScanner. But I’ll need to perform a “shoot-out” between these scopes outside of light-polluted urban skies to confirm.

Right now, I see the collapsible tube Bushnell Ares 5 (BA5) as the scope that will eventually replace the SkyScanner as my deep-sky instrument once I’ve gone as far as I can with the latter. This is an F/5 130mm Newtonian which thanks to its unusual design, weighs only about 6.5 lbs. for the OTA. At only $164.99 (with no shipping or sales tax) from Optics Planet, this is probably the best scope deal in the country right now.

Here is the scope with the tube collapsed, mounted on an Orion VersaGo II (because of its bulkiness, I’ve discarded the 6.5 lb. tabletop mount that came with this scope).

And here is the scope with the tube extended all the way out.

I’ve created a light shroud made out of black felt to cover the open tube and protect it from the elements while observing.

In the limited amount of time I’ve used this scope in both light-polluted and semi-dark skies, I’ve had a tantalizing taste of what 130 mm. of light gathering power can show. In my light-polluted front driveway with direct vision, I was able to see the ring shape of M57 for the very first time, using only 65X magnification. With the 100mm SkyScanner, I can barely make out shading within the interior of the oval-shaped disk at 80X or more using averted vision in darker skies. Less than two months ago, I took my BA5 out to a semi-dark (orange-zone) site for the first time. M13 looked nothing like the views I saw through the SkyScanner – at 130X, this globular was just exploding with stars all over the place. Ditto for M5.

As Matt has shown us through his reports on using “Stubby Fats” in the desert, you can do some serious deep-sky observing with a 130 mm F/5 Newtonian in semi-dark or dark skies.

But the BA5 has to wait until I’ve exhausted all the possibilities of the 100mm F/4 SkyScanner.