Archive for the ‘C102’ Category


Observing Report: Night of the Refractors redux

November 20, 2013

From left to right: my TravelScope 70, my C102, David’s C102. When I took this picture, we hadn’t put the finders on the big scopes yet, or gotten my stand-alone GalileoScope set up yet.

This one is a little late: David DeLano and I spent the night of Sunday, November 3, observing at the Salton Sea. This is the belated observing report.

We met up at the visitor center at the headquarters campground. We rendezvoused there a little after 3:00 in the afternoon because we had some things to do before sunset, which because of the time change was coming at 4:50. The visitor center gift shop has a little astronomy section and both of us picked up a copy of the Sky Atlas for Small Telescopes and Binoculars, by Billie and David Chandler–more on that atlas another time. David also picked up a nice plasticized version of the Chandler planisphere.

Chandler Sky Atlas

After that we drove down to my favorite spot at the Sea, which is the south end of the Mecca Beach campground. A couple at another site were loading up as we were pulling in, and the left a few minutes later. After that, we were the only humans at the campsite all night long, except for someone in the late evening who pulled in, turned around, and left, all without stopping.

Our first activity was dinner at a picnic table in the shade. We split the gear and groceries like so: David supplied firewood and snacks, and I brought dinner (Subway sandwiches) and cooked breakfast (pancakes).


Even as we were eating, the second activity commenced: the exchange of hostages. As far as I can tell, David is a hot rod mechanic who happens to work on small refractors instead of cars; if that strikes you as hyperbole, just read on. Anyway, he’s way more adept at getting refractors to sing than I am, so I had brought him an unfinished Carton 60mm f/15 refractor and a couple of small objectives that I had rescued from otherwise unsalvageable garage sale scopes. To transfer into my care, David had brought a nice Celestron 2-inch star diagonal for my C102, and–most importantly–a GalileoScope that he had built and modded for me.

Galileo is Rocking Out in His Grave

The GalileoScope was created for the International Year of Astronomy in 2009, when it originally sold for $15. That was mostly down to economy of scale; now that sales have cooled, the price is up to about $50. It’s still a lot of telescope for that price. David’s GalileoScope mods have been featured here before.

The stock GalileoScope is a straight-through instrument with an f/10 objective and a push-pull focuser, which you aim by looking along some gunsight-style ridges on top of the OTA. My GS has had its tube chopped to accommodate a Stellarvue 90-degree diagonal with a helical focuser (the #D1026AF unit here, if you want one for yourself), and has a Daisy red-dot finder perched on the forward gunsight.


Above, my nicely tricked-out GalileoScope. Bottom, David’s insanely modded version–possibly the most attention anyone has ever lavished on a cheap build-it-yourself 50mm refractor.

Lest you get too jealous of my pimped-out GalileoScope, let me describe David’s own GS. He got the aftermarket f/11 objective kit, which lengthens the light path enough to allow the use of a diagonal without chopping the tube. At the back end of the scope, there’s a 2″ Crayford focuser (yes, you read that right) with a 1.25″ adapter. His diagonal also has a helical focuser for fine-tuning; in fact, in use I forgot about the Crayford and used the helical focuser exclusively. At the front end, there’s some kind of fancy RDF, sold by Cabella’s for use by hunters, with the largest eye-lens I’ve ever seen apart from the “boxy” astro-only unit-power finders, the Telrad and the Rigel Quikfinder. A set of nice rings with Delrin-tipped screws completes the instrument, and allows David to mount it coaxially with his larger scopes as possibly the most awesome luxo-finder-slash-second-instrument that I’ve ever encountered (on a small scope; the 9.5-inch refractor mounted on the 12-inch Zeiss in the Griffith Observatory probably takes the cake for larger instruments).

David’s GS really must be seen to be believed. Once on the Dinosaur Mailing List, Mickey Mortimer wrote, “Looks like it’s time to over-technicalize this previously tame post.” I can’t think of David’s GS without those words going through my mind. I wouldn’t be surprised if it is the most extensive hack anyone has done on a GS. It is definitely the most badass.

I should mention that getting both of the GalileoScopes to work as well as they do involved a lot more than just throwing some nice parts on. It required a lot of work and thought and experimentation. Happily, David documented the process and will have a guest post about his adventures in GS-hacking in the not-too-distant future. So stay tuned for that.


David’s GS mounted on his C102 as the luxury finder to end all luxury finders.

After dinner and the exchange of hostages, it was time to set up scopes. I was rolling with the C102/SV50 combo again. I also set up the TravelScope 70 just to have something different to plink around with. David set up his second tripod for my GS, and put his mod-tastic GS on his own C102, using a third tube ring to support the GS stalk and rings. This makes for an imposing setup. I studied it as intently as an American astronaut getting his first look under the hood of a Soyuz capsule. We used some antennas on a distant mountaintop to get everything aligned, and then almost immediately we were off and running.


Our first target, at 5:30, was Venus. There wasn’t much to see–basically a very bright half-circle–but checking in just feels like the right thing to do.

Next we turned to the Double Cluster and Stock 2 and spent a few enjoyable minutes tracing out the loops and chains of stars in our various instruments. Like last time, I could see the red stars in NGC 884, and if anything they were easier this time since I knew what to look for.

After that we turned south and did a big tour of the Sagittarius/Scutum area, eventually going north into Aquila and then west through Serpens to Ophiuchus. But I’m getting ahead of myself.

We started with the teapot asterism in Sagittarius, and let that guide us to M8, the Lagoon Nebula. Then we hopped up just a bit to M20 (the Trifid Nebula) and the open cluster M21. After that we took a break to hit M13 in Hercules before it sank down into the light dome over Palm Springs. We returned to Sagittarius with globs on the brain and took in M22, which I thought was a serious contender in the field of majestic globs. Then it was up to the M24 star cloud, where we got lost for a few minutes at the sight of literally thousands of stars in our eyes. Somewhere in Seeing in the Dark–and irritatingly I cannot find the passage right now–Timothy Ferris describes a swath of the sky, possibly M24, as a “wonderland of far-flung suns”. Whether he intended it for M24 or not, it’s an apt description.

At the risk of letting my current bout of refractoritis get the best of me, I must say, the view of M24 through the C102 was just breathtaking. Now, I have visited M24 before, many times. It is one of my favorite places in the sky. But I had not taken a good look at it through a decent-sized refractor under dark skies. The contrast was superb: against a jet-black background, the stars were so finely graded by brightness that I noticed rivers and shoals among them that I had never been aware of before, including a current of brighter stars running north-south and paralleling the Milky Way. Truly, this is the backbone of night.

But even in a palace, one can want for variety (or so I’ve heard), so we ventured onward. Past the open cluster M18 we came to the Swan Nebula, M17, very bright and clear and looking just like its namesake. Then farther up we found M16, the Eagle Nebula, its tendrils of glowing gas wrapped around a dense cluster of newborn stars. Then back to M24 to pick up the open clusters M25 and M23, which attend the majestic star cloud like obsequious courtiers. M25 is one of my favorites; it sits at the center of a curving arc of stars that David describes as a spiral, but that to me has always looked like a fishhook, with M25 as the bait.

After working through all of those objects with the scopes, we stopped for a binocular tour. I had along my Nikon Action 10x50s and David was rolling with his Nikon action 10x40s. I found that if I held David’s green laser pointer between two fingers of my right hand and the binoculars, I could aim the laser beam at the center of my field of view. We shared many sights over the course of the evening using this trick. For starters, we revisited all of the Sagittarius clusters and nebulae mentioned above, and picked up the little glob M28 as well.

DeLano 1 chart - wide

The asterism “DeLano 1” next to Mu Aquilae. It is much more obvious than this Stellarium view shows, and looks more like a bright open cluster.

Then we turned north to Scutum and Aquila. Our first stop was M11, the Wild Duck cluster. Then I took a break for bathroom and snacks, and David went crazy finding new things. When I got back to the scope, I had some catching up to do: the open clusters IC 4756 in Serpens, and NGC 6633 and IC  4665 in Ophiuchus. David had also discovered something pretty that was not listed on any of our charts: a small group of bright stars just north of Mu Aquilae. So far I have not found this listed anywhere as a named object; for the heck of it we called it DeLano 1.

DeLano 1 chart 2 - narrow

A closer view of DeLano 1.

Zoom Zoom Zoom

I see that I have not mentioned what I was using for eyepieces. Thanks to the 2″ diagonal I could use my 32mm Astro-Tech Titan, which gives a wider true field than any other eyepiece I own. In the C102 it gives a magnification of 31x and a 2.2-degree true field of view, which was great for framing almost everything we looked at (the Pleiades fit with a little room to spare, even). My only other 2″ or dual-barrel EPs are the 21mm and 13mm Orion Stratus EPs, which I used infrequently Sunday night. When I wanted more power, I put in the 1.25″ adapter and my new toy, the Celestron 8-24mm zoom eyepiece.

My only previous experience with a zoom EP was a Scopetronix 7-21mm, which was pretty stinky. Zoom EPs always have wider apparent fields of view at high magnification and narrower AFOV at low magnification. That is pretty much the opposite of ideal, but physics is physics, and the comparatively narrow apparent field is tolerable as long as it doesn’t get too narrow–below about 40 degrees you feel like you’re looking through a soda straw. Unfortunately, with the Scopetronix zoom, the AFOV started at 40 degrees (at high mag) and ended up somewhere below 30, at which point the image is so small you might as well be looking through the other end of the telescope.

Happily the Celestron 8-24mm zoom has a more generous AFOV. The stated range is 40-60 degrees, and that seems about right to me. What’s not so great? It’s not parfocal across its magnification range (I don’t know how many zoom eyepieces are), so you have to refocus as you change magnification. Also, it’s a little soft at high power. Not egregiously so, but my 8.8mm ES82 is not going to be losing any sleep. On the plus side, it’s decent, convenient, and at a current street price under $55, dirt cheap.

Incidentally, this is the danger of getting a couple of high-end eyepieces: they are so sharp and so clear that when you go back to merely average EPs, the differences are immediately noticeable. It makes you spoiled.

Lyra, Cygnus, Vulpecula, and Sagitta

After I got caught up in Ophiuchus, we turned north, first to Polaris and the “Engagement Ring” asterism, and then to the Lyra/Cygnus/Sagitta area.

Naturally our first stop was Epsilon Lyrae,  the “double double” star, which was cleanly split at 125x with 8-24mm zoom. So if you’re curious about that eyepiece, there’s a point in its favor.

After that we followed my usual J-shaped path through this  region: from the Ring Nebula, M57, on past the fair-to-middlin’ glob M56 to the brilliant, contrastingly-colored double star Albireo. Like a lot of double star observers, I like doubles when they’re not too widely split, and at 31x the 32mm Titan and C102 gave perhaps the best view of Albireo I’ve ever had in a scope. After Albireo, go straight south to find Collinder 399, better known as Brocchi’s Coathanger. Southwest of the Coathanger one comes to the pair of closely-spaced, equally-bright stars that mark the feather end of the constellation Sagitta, the arrow. Halfway along the arrow a zig-zag pattern of stars leads to the faint glob M71. Then proceed along the arrow to the third bright star up from the feathers and hang a right to find M27, the Dumbbell Nebula.

The Dumbbell does a neat trick as either one’s scope or one’s sky conditions improve. From a small scope, or a big one under city lights, it looks like a bow tie. As things get better, the ends of the bow tie sprout extensions to either side, so the nebula starts to look more like an apple core. Finally the area to either side of the apple core starts to fill with nebulosity, so the nebula ends up looking like a football with a bright band–the former bow tie/apple core wrapped around its “waist”.

10-04-2008_DumbellThe football form of the nebula is obvious in most astrophotos of M27. Here’s a nice example by Rogelio Bernal Andreo ( that shows the different aspects in different colors: white bow tie center, red apple core extensions, blue football wings. I have seen the football before in the XT10, but I had never seen it in a small scope before Sunday night. And, to be clear, the C102 did not show the entire football. But it did definitely show the wisps of nebulosity extending out on either side of the apple core. It’s probably  best to say that M27 was halfway between  the apple core and football forms. It was missing the crisp cut-off at the edge of the football, which the XT10 will show under sufficiently dark skies. But it was still way more than I expected. I am still learning what a 4-inch scope with high contrast can do under dark skies; the answer is, “an awful lot”.

The striking appearance of M27 can in part be chalked up to excellent transparency in the early evening. Another example is that both of us could clearly make out the North American Nebula, NGC 7000, in the binoculars. My best-ever views of the nebula have been with 15×70 bins out at Owl Canyon. I have caught glimpses of it in the 50mm glasses before, but never as good as it was Sunday night. David was getting it clearly in his 40mm bins, which is pretty amazing.

We did another binocular tour in this area, hitting all of the objects listed above as well as M29, M39, the heart-shaped asterism around the bright star Sadr in the heart of Cygnus, and the wide blue/orange binocular double Omicron Cygni. This was about 8:30 PM, four hours into our 9-hour run.

This is pretty much how we proceeded for the rest of the night: pick an area, figure out some of the best and brightest objects therein, and hop our way through them. David was working off the Evening Sky Map and suggesting objects from its lists, and I was working from the PSA and rediscovering some goodies I hadn’t seen in a while. Rather than give an exhaustive list of everything else we saw, I’ll just list some highlights:

NGC 253 and NGC 288 – NGC 253 is the Silver Coin Galaxy. It’s up there with Andromeda (M31), the Whirlpool (M51), the Sombrero (M104), and Bode’s Nebulae (M81 & M82) as one of the best galaxies for northern hemisphere observers. My first view of it was in binoculars from Big Bear Lake, and under those dark mountain skies it looked as good in the 15×70 bins as a lot of galaxies look through a telescope. Mottled details is visible in even small scopes under sufficiently dark skies. While you’re in the area, might as well drop down about one eyepiece field and pick up the globular cluster NGC 288.

NGC 7789 – Here’s one I’d seen before but forgotten about. This is a nice open cluster off the tip of Cassiopeia, sandwiched between two small groups of bright stars. There are a lot of open clusters in Cassiopeia–we did a third binocular tour that encompassed NGC 457, NGC 436, M103, NGC 663, NGC 659, NGC 654, and Cr 463–but NGC 7789 might just be the best, not only for its inherent charm but for the rich surroundings in which it is set.

M37, M36, M38 – This is the famous trio of open clusters in Auriga, which are among the most popular and  most visited objects in the winter sky. The one that impressed us the most Sunday night was M37, the lowest (east-most) one. It is a dense swarm of tiny stars, which David described as “crystals”, and which to me looked like the proverbial scattering of diamonds on black velvet.

M46, M47, M93 – These open clusters in Puppis are also popular winter objects, especially the close pair of M46 and M47. I suspected the planetary nebula NGC 2438 in M46, which I first spotted at the All-Arizona Star Party back in 2010. Since then, I always look for it, and when I do spot it, I wonder how I was able to go  for so long without seeing it.

M76 – This is the Little Dumbbell Nebula in Perseus, and one of just a handful of planetary nebulae in the Messier catalogue (the others are M27, M57, and M97). As its name implies,  the Little Dumbbell is the smallest and probably least impressive of the Messier planetaries, but I’ve always had a fondness for it. Although small, it has a high surface brightness so it’s not hard to spot if you know where to look, and it is not without its charms.

Planetary nebulae illustrate why the Messier catalogue is a two-edged sword. On one hand, the Messier catalogue does include some best-of-class objects in almost every category of DSO; on the other hand, there are numerous objects in other catalogues that outshine (sometimes literally) the less impressive Messiers. For galaxies, you have things like the Silver Coin and NGC 4565 in Coma Berenices; for open clusters, look no farther than the Double Cluster in Perseus and NGC 663 and NGC 7789 in Cassiopeia; for diffuse nebulae, see the Flame Nebula (NGC 2024), the Rosette (NGC 2237), and the Christmas Tree or Cone Nebula (NGC 2264).

But planetary nebulae get especially short shrift; a quick-and-dirty list of impressive non-Messier planetaries in northern skies includes the Cat’s Eye (NGC 6543), the Eskimo (NGC 2392), the Saturn (NGC 7009), the Ghost of Jupiter (NGC 3242), and the Blinking Planetary (NGC  6826). This is not because Messier had anything against planetaries but because his catalogue was discovered rather than assembled post-hoc, and discovery is always a haphazard process. Still, we are not discovering these things for the first time, and with their often high surface brightness and charming array of forms, planetary nebulae are great targets for beginning and city-bound observers.

By 2:00 AM we were winding down, and so were the skies. A cloud mass that had been hovering over Palm Springs started to send forth offspring, and the haze near the horizon was getting worse. A bright star in Leo that I just couldn’t place turned out to be Mars. We had one last look at the Double Cluster and called it a night.

It was one of the most fruitful observing runs I’ve ever had. By my count, we looked at:

  • 49 Messiers
  • 20 NGC, IC, Collinder, etc., objects
  • 4 double stars (counting Epsilon Lyrae only once)
  • 4 asterisms (DeLano 1, the Engagement Ring around Polaris, the Heart around Sadr, and Kemble’s Cascade)
  • 3 planets (Venus, Jupiter, Mars)

So about 80 things in the sky, not counting the numerous shooting stars, which we noted every few minutes all night long. That is by far the most things I’ve seen in one evening when I wasn’t doing a Messier Marathon. But we weren’t rushing or trying to get through a ton of objects, we were just basically out for a spin, and if you cruise around the sky for 9 hours, you are going to end up seeing a lot.


I came away from the evening with a couple of firm directions for future observing.

First, I don’t think I logged anything that I hadn’t seen before (DeLano 1 excepted!), but I saw a lot of stuff that I had forgotten about, like NGC 7789. Most of these were things that I had visited in the course of doing one or another Astronomical League observing program. That’s great because those programs have helped me to learn the sky, and they’ve introduced me to a lot of wonderful objects that I hadn’t seen before. But now that I know the sky, I need to go back and re-observe those things and spend a little more time with them. This is especially true of the many beautiful clusters on the Deep Sky Binocular observing list–I am ashamed to say that there are many of those that I still have not visited with a telescope. So even my terra cognita holds some wonderful things waiting to be rediscovered.

Second, I need to go south (in the sky)! Here’s some relevant math: the Salton Sea campgrounds are at about 33 degrees north latitude. That means that Polaris is 33 degrees above the northern horizon, the celestial equator is 57 degrees above the southern horizon, and with no intervening landforms or atmosphere I should be able to see down to -57 degrees declination when I look south. Now, in practice the near-horizon haze makes the last few degrees pretty worthless. But I have seen the globular cluster Omega Centauri with my naked eyes from the Salton Sea. At -47 degrees declination, it never gets more than 10 degrees from the horizon. If it’s naked-eye visible that low under good conditions, then binoculars and telescopes will reveal much more at the same declination, and maybe even a little lower.

In practice, I have explored almost none of that southern expanse. I am used to thinking of the Silver Coin galaxy as a far southern object, but at -25 degrees it culminates a full 32 degrees above the horizon–more than a third of the way to the zenith! Except for sighting Omega Centauri a couple of times, I have not deliberately gone south of about -30 degrees declination (and I’ve only gotten there in the area around the “tail end” of Canis Major), which leaves a LOT of unexplored sky out there. I was fortunate to get to see most of the best of the southern hemisphere sky when I was in Uruguay in 2010 and it was amazing. Much of what I saw there is visible from here, I just haven’t looked. I need to fix that.


Guest post: Photographing the moon with the Celestron 102GT

October 21, 2013

Here’s the first guest post by frequent commenter and sometime observing buddy Doug Rennie. He’s using the same OTA I’ve been using recently–the Celestron 102GT achromatic refractor–but the rest of his setup is different from mine: different mount, diagonal, eyepiece, and camera. Just goes to show that this scope plays well with lots of other gear. I flipped some of the photos to match the orientation of the moon in the sky, but otherwise they are as Doug sent them. The captions and any errors therein are mine. Enjoy!

IMG_3393 - Northeast quadrant

The northeast quadrant of the moon. The landing sites for Apollo 11, 15, and 17 are all in this quadrant.

So I went out several nights last week with the waxing gibbous moon looming large and bright over our front courtyard, and took out the C 102 on a Porta II with my Celestron 8 x 24 zoom attached to my DSLR for some eyepiece projection AP. Took a lot of photos, most of them so-so to utter crap, but maybe 8 or so not half bad. I still need to focus more on . . . focus. Note in the photo that I insert the zoom/camera into a 2″ High Point Scientific 99% dielectric diagonal vs directly into the focuser as this is a lot easier to work with, and having done it both ways, I really see no image quality drop-off using the diag.

Scope and camera setup

The Celestron 8 x 24, as you can see from the photos, allows the removal of the rubber eye cup which exposes a threaded male connection; this allows the eyepiece to be mounted directly to the t-ring on my Canon T1i DSLR. Eyepiece projection photography. I found that to achieve focus using the LED LiveScreen at the back of the camera (which works well; my eyesight is the issue here) that I need to run the shutter speed up into the 3-4 second range so that the image is bright enough to both fill the screen and capture the necessary (for focusing) details. Once I have focused, I then move the shutter speed back to that which I will actually be shooting at, usually (depending on brightness and how much of the darker Mares fill the screen) anywhere from 1/30 to 1/160, the most common being around 1/60, ISO set at 800 for most.

Closeup on diagonal eyepiece and camera

I also use a remote shutter release cable (about 4 bucks through eBay) to cut camera movement/vibration down to next to nothing.

With the zoom, I can go everywhere from 42x to 125x magnification, and everywhere in between, with a quick quarter turn.

The north-central portion of the moon. The smooth dark crater on the lower left is Plato, and the deeply-shadowed crater with the bright rim far to the north is Philolaus.

The north-central portion of the moon. The smooth dark crater on the lower left is Plato, and the deeply-shadowed crater with the bright rim far to the north is Philolaus.

The C 102, as you pointed out in your report, serves up wonderfully bright, sharply-resolved images and much of this comes through in the photos. Any soft edges are more the result of my less-than-perfect focusing than with any of the optics involved.

Also, these are all single shots: focus, click, move on. Stacking? We don’t use no stinking stacking!

The prominent crater in the upper middle is Copernicus, with the Apennine mountains curving away to the northeast, marking the rim of Mare Imbrium, the Sea of Rains. Near the lower left are three craters making a backwards comma--these are Ptolemaeus, Alphonsus, and Arzachel (Arzachel has a prominent central peak).

The prominent crater in the upper middle is Copernicus, with the Apennine mountains curving away to the northeast, marking the rim of Mare Imbrium, the Sea of Rains. Farther down and to the right are three craters making a backwards comma–these are Ptolemaeus, Alphonsus, and Arzachel (Arzachel has a nice central peak).

I am now waiting until Jupiter and Saturn again appear in my observing window, along with M42, M45 and other brighter DSOs as I believe I can capture some decent images with my current set-up, as long as I don’t need to go longer than 12-15 seconds. We’ll see.

This shot is from a few nights previous to the last one. Now the backward comma formed by Ptolemaeus, Alphonsus, and Arzachel is right on the terminator, just slightly above and right of center.

This shot is from a few nights previous to the last one. Now the backward comma formed by Ptolemaeus, Alphonsus, and Arzachel is right on the terminator, just slightly above and right of center.

Frankly, I never see myself getting heavily into AP as the costs alone are prohibitive, plus all the technical stuff overwhelms me just thinking about it. That, and it seems to me that too many of these big time AP guys do little, if any, visual observing, that their views of the heavens mainly come after the fact when they look at the photos they took. Not me. My biggest joy is still what I see at the moment via the EP. But it’s still fun to screw around with modest gear/modest goals AP, especially when its Moony out and that’s about all there is to do. But I am eager to try my new eyepiece projection technique on Saturn and Jupiter when they next appear, and am optimistic that I can even score some good photos of brighter DSOs such as the Orion Nebula and the Pleiades, which won’t be long now.

The bright crater above and left of center is Tycho--note the rays of ejecta that point back to this young, well-defined crater. Below Tycho is the much larger, worn Clavius, with a nice arc of craterlets of decreasing size on its floor.

The bright crater above and left of center is Tycho–note the white rays of ejecta on the right that point back to this young, well-defined crater. Below Tycho is the much larger, worn Clavius, with a nice arc of craterlets of decreasing size on its floor.


The Rule of Ones

October 19, 2013
C102 2013-10-18

Tonight: one scope, one target. Here’s the scope.

I have several distinct modes as a stargazer. Sometimes I’m in exploration mode and I want to see and log new objects. Sometimes I’m in gear mode and I want to see how a given piece of equipment performs. Sometimes I’m in aesthetic mode and I just want to look at beautiful things. Sometimes I do all three in one night, or even looking at one object.

The last post, about current and future observing projects, was written in exploration mode. “Exploration” might seem like an odd word to apply to the activity of tracking down lists of things compiled by other observers. But if I haven’t seen them myself, then there is still the thrill of the hunt and the rush of discovery. And looking at all of these things is how I personally transmute caelum incognitum into known space. That’s exploration in my book.

Saturday night at the Salton Sea, I was in a blend of aesthetic mode and gear mode, because my ongoing thought process was basically, “Oh, hey, that beautiful thing is up now. I wonder how it looks through these scopes?” I think the only new thing I logged was 8 Lacertae, and if I hadn’t been so close to fiinishing the Double Star program, I wouldn’t have logged any new objects at all, despite staying up almost all night.

I do like observing lists. Some people dismiss them as stamp collecting or say that they make a fun pursuit into work. Well, different strokes, I guess. For me, observing lists come with the implicit subtitle, “Hey, here are the next n-hundred things that are really out there to be seen, any of which might knock your socks off.” Every observing program I have completed has introduced me to new favorite objects, which I periodically revisit, and has broadened my knowledge and experience of the cosmos.

But with all of that said, I don’t do enough casual stargazing, with no plan or agenda. That’s all I used to do, in my first few months as an amateur astronomer, and it almost killed me. Observing programs gave me a way to simultaneously learn the sky and educate myself about what’s up there. But the pendulum may have swung too far now; I hardly ever haul out a scope just to take a quick peek at the moon or Saturn.

All of this is on my mind because of a thread on CN called “When astronomy becomes a chore….” Here’s are some excerpts that have been much on my mind:

RussL: If I feel lazy I can get by with just the 120ST and my trusty TV Widefield 32mm. That way I don’t even have to feel obligated to see each object at every power I can. Easy.

Me: Peace through deliberately limited options–I love it! You have inspired me, sir.

RussL: Well, thanks. I’m glad to know my laziness has helped someone. But, it’s true that sometimes we need to relax more. It’s kinda like when I was a kid with next to nothing to view with, but happy as a clam with whatever I had. I have much more now, although not all that much. I guess part of the difference nowadays is that I have so much more knowledge and feel like I need to use it more. But there’s also a lot to be said for just having a good time without feeling like I must do everything possible.

karstenkoch: I’ve been mentally kicking around an idea for awhile that is still taking shape in my head. For lack of anything better to call it, I’ll call it the “Rule of Ones”. I’ve seen some comments above like it, so I thought I would mention it. There’s really nothing to it other than in order to keep things simple, easy, pure, and enjoyable do or choose only one of everything. Take one scope outside. Take only one eyepiece too. Pick one target to observe. You can imagine all of the other variables involved … choose or do only only one of each. Then, with no more decisions to make, just have a rest under the stars and enjoy your time observing and reflecting.

I like that. One scope, one eyepiece, just go. That sorta dovetails with another idea that has been growing in my mind–more on that in the next post.

Full moon - Oct 18 2013

And here’s the target.


Observing report: Night of the Refractors

October 14, 2013


London and I were back at the Salton Sea this past Saturday night (Oct. 12-13). It was our first time there  since my accidental Messier Marathon back in March. In between times it has been too darned hot to go camping in the desert. It was good to be back.

C102 at Mecca

The  big news was that I was rolling with a new scope: a Celestron C102 f/10 achromatic refractor, one of the “screaming deal” scopes from this post. I put it on the SkyWatcher AZ4 (= Orion VersaGo II) alt-az mount where my Apex 127 Mak usually rides. The included dovetail on this scope is too small and too far forward to balance well with an optical finder and heavy eyepieces, so I sprung for the Explore Scientific tube rings and dovetail kit. That was a pretty darned good deal; tube rings alone for a 4-inch scope run $30-40, and a decent-length dovetail is another $15-20, but the ES kit has both for $45, plus a very convenient carry handle opposite the dovetail bar. With the rings in place I could mount my StellarVue SV50 as a finder, and I was ready to go.


I also brought along the Apex 127 in case I felt like a change of pace, and because it takes up almost no room (which is one of the reasons I got it in the first place). But I was having too much fun with the C102 and the Apex 127 never made it out of the case. At some point I’ll have to do a detailed comparo between the two scopes, but Saturday night I was just out to have a good time.

We also had along the Celestron Travel Scope 70, which London is using in the photo above. I had completely disassembled and reassembled that scope, and after London went to bed at 10:00 I divided my time about equally between the C102 and TS70. Partly I wanted to put both scopes through their paces, and partly I just wanted to hop around the sky, checking in on friends new and old.

C102 1st quarter moon 2013-10-11

I will have to do a full-on review of the C102 at some point. For now, suffice it to say that it is a very nice scope. Image brightness and contrast are both excellent; for someone who has spent most of his time observing with reflectors and catadioptrics, this does not feel like a 4-inch scope. On most objects I could have been fooled into thinking I was looking through a 5- or even 6-inch mirror scope.

Grain of salt: I didn’t actually go back and forth between this scope and 5- or 6-inch mirror scope, although I plan to do that in the future. I’m just saying that as someone who has spent a lot of time looking through smallish Newts and Maks, this scope felt like it punched above its weight. I was worried that I would feel like I was missing out by taking such a small scope as my main instrument. But I was having so much fun with it that I stayed up nearly to dawn–there were always two or three more things I wanted to check out.

The photo above is not from Saturday night but from my driveway on Friday night, when the moon was exactly at first quarter. I flip-flopped it left to right and lightly sharpened it in GIMP, but didn’t fiddle with the brightness or color. There is some false color, most notably along the limb of the moon and on bright planets like Jupiter, but I didn’t find it objectionable. YMMV.

Salton moonset composite 2013-10-13

I think this is my new favorite moon scope. The image is so contrasty, details just pop. I would put in the 6mm Expanse (167x), watch the moon drift across the field of view, and pretend I was an astronaut. I also sketched a really nice catena (crater chain) in the northeast quadrant of the crater Deslandres. You can see it on the right in this LPOD image, opposite the smaller crater Hell that sits in the western part of Deslandres. If this catena has a name, I haven’t discovered it yet; feel free to enlighten me in the comments.

The moon set precisely at 1:00 AM. As you can see from the above composite, the seeing was not fantastic, especially near the horizon. Stars were visibly twinkling below about 45 degrees elevation.

After the moon set, it was like a whole new sky. The Milky way fairly blazed, and the sky was so full of bright stars that it was almost overwhelming. I was about as happy as I have ever been.


I spent some time observing near the zenith. This can be a pain with a long-tube scope like the C102. You can extend the tripod legs to put the eyepiece at a convenient height, but then you’re futzing with tripod legs all night long, which I loathe doing (another reason I got the Apex 127 was that I can go from horizon to zenith at one tripod setting). I remembered David DeLano saying that he often sits on the ground to observe at high angles, and that led to some experimentation. I found that my range of comfortable sitting eyepiece heights overlaps with my comfortable kneeling eyepiece heights, so I put out a camp pad for my knees and a folding chair for my elbows and voila. Someday I will build or buy an adjustable observing chair, but until then, this will do.


I have a couple collapsible camp chairs. They are great for stashing eyepieces when I’m really rolling, because I don’t have to worry about them falling over and rolling off onto the ground like I would with a table. I keep my eyepiece case on a picnic table, well back from the edge, so there’s no real opportunity to knock it over.

Now that I have some nice Explore Scientific widefields, I have become a bit of an eyepiece snob. Early in the evening I was sharing views with London and people from a nearby campsite so I started with my “second string” of Orion Stratuses and Plossls, just in case. Sound like a jerk move? Just wait until some kid–or a grown-up relative, in my case–says, “Hey, do I look here?”, and stabs the eye lens of your favorite eyepiece with a greasy fingertip.

But I guess the joke’s on me because the views through the second string EPs were so good that I never got around to hauling out the ES models. My lineup for Saturday night included:

  • 32mm Plossl (31x, 1.7 degree true field of view) for lowest magnification and maximum true field in a 1.25″ EP (I don’t have a 2″ diagonal yet so my 38mm AstroTech Titan, which would go even lower and wider, stayed home);
  • 25mm Plossl (40x, 1.3 degrees);
  • 21mm Stratus (48x, 1.4 degrees)–comparing this to the 25mm Plossl illustrates one of the nice things about widefields: you can get higher magnification (bigger image scale) and a larger true field (more actual celestial real estate) at the same time;
  • 13mm Stratus (77x, 0.88 degrees);
  • 12mm Plossl (83x, 0.63 degrees);
  • 6mm Expanse (167x, 0.40 degrees).

You would think that the Stratuses would put the 25mm and 12mm Plossls out of business, since they give basically the same or better magnification and a bigger true field. But the Stratuses are quite a bit heavier than the Plossls and required rebalancing the scope. So I was either in Stratus mode or Plossl-and-Expanse mode, and over the course of the evening, the cheap eyepieces won out in terms of convenience.

Also, frankly, f/10 is a pretty forgiving focal ratio. With a light cone that shallow, practically any eyepiece is going to do well. The only reason to prefer widefields is for their actual wide fields, and not to help control aberrations from the scope itself. I did note that the difference in apparent field of  view was immediately obvious when I bounced from the 52-degree Plossls to the 68-degree Stratuses. Oddly, I never noticed it with the 6mm Expanse (66 degrees), but I think that’s because I only used the Expanse to power up on the moon, planets, and double stars, where I was always fixated on whatever was at the center of the field.

My favorite observations of the night, in rough chronological order:

Double Cluster and Stock 2

I have waxed poetic about the Double Cluster before (you can find it here). It’s pretty close to a larger, sparser cluster called Stock 2, which is shown is most atlases, including the Pocket Sky Atlas. But I had never noticed the chain of bright stars that connects Stock 2 and the Double Cluster, and I had also not picked up the stick figure in the center of Stock 2. Here’s a photo by Doug Scobel of the University of Michigan Lowbrow Astronomers (borrowed from here) that shows what I mean (lower image GIMPed by me):


I revisited the Double Cluster periodically throughout the night. Right after dark it was the second thing I looked at, after the moon, and it was my last object before I packed up at 5:40 AM. Probably my best view was at 3:00 AM, when I wrote:

Nicely framed, mesmerizingly beautiful. I see at least two red stars in more easterly cluster, NGC 884. NGC 869 is at end of chain to Stock 2. All at 31x.

I still do plan to get into astronomical sketching, and when I do, I reckon the Double Cluster will be one of my first targets, if not my very first.

Andromeda Galaxy (M31) and satellite galaxies (M32 and M110)

Also about 3:00 AM, immediately before the Double Cluster observation above:

With 32mm Plossl (31x), all three galaxies fit in field, with dust lane popping in and out in averted vision.

I should mention that M31 itself was too big to fit into the field of view of my lowest-power eyepiece; with the core of the galaxy centered in the field, the edges of the spiral arms went out of the field in both directions. M31 is so darned big that unless you have an instrument with a 3-degree true field, you just can’t see all of it at once. Corollary: if you can fit the galaxy into a smaller field of view, then you’re not seeing all of it, which is sadly the case under even moderate light pollution. The core will punch through even vile city lights, but the spiral arms just die out.


Best view was at 5:00 AM, with the 12mm Plossl (83x):

Bands not quite lined up with moons. NEB [North Equatorial Belt] seems narrower and better defined than SEB. Several distinct belts to north, single broad ?temperate belt to south. Max detail at this mag–at 187x, seeing is too mushy.

Zodiacal light

I stopped about 5:10 for a biology break. Walking back to the telescope, I was stopped in my tracks by what seemed to be a second Milky Way: a broad band of light stabbing up from the eastern horizon, past Mars and the Beehive (M44) and reaching almost to Jupiter, which was by then high in the sky. It took me a minute to realize that this was the zodiacal light: the cumulative effect of sunlight reflecting off of countless grains of dust in the ecliptic plane of the solar system. The name “zodiacal light” comes from the fact that this light is always found along the zodiacal path traced by the sun, moon, and planets, as it must be, since almost everything in the solar system orbits in roughly the same ecliptic plane (comets excepted–they can come in from any angle, and the fact that they do so was one of the first clues to the existence of the Oort Cloud).

The Gegenschein, which I saw at the 2010 All-Arizona Star Party, is another manifestation of the same phenomenon. Basically, the Gegenschein comes from “full” dust grains exactly opposite the sun in the sky, and the zodiacal light comes from “crescent” or “gibbous” dust grains at other angles. Apparently under the very darkest skies, the Gegenschein can be seen as a bright patch in an arc of zodiacal light that stretches overhead from horizon to horizon. I have not seen that, but it’s on my bucket list.

Anyway, given how bright the zodiacal light was Sunday morning, I think I must have seen it many times before and simply not recognized it. I will keep my eyes peeled in the future.

M81 and M82

Anytime I’ve got more than one bright galaxy in the eyepiece, I’m a happy man. These two were nicely framed in the 32mm Plossl (31x). Using the 12mm Plossl (83x), the gravitationally-tortured M82 showed some hints of detail in averted vision.

The Odd Couple–M97 and M108

Probably my favorite pair of Messier objects. M97, the Owl Nebula, is a planetary nebula, a single dying star, about 2000 light years from Earth–right next door, cosmically speaking. M108 is a spiral galaxy in the Ursa Major galaxy cluster, about 46 million light years away, roughly the same size as the Milky Way and containing perhaps half a trillion stars. So one of these things is 23,000 times farther than the other one, and several hundred billion times more massive. If M97 was a ping-pong ball held at arms length, M108 would be a frisbee half a mile wide, located 8.5 miles away. But they look about the same in the telescope in terms of size and brightness, and you can frame them in the same low-power field of view, as I did at 5:27 AM on Sunday.

(Incidentally, I just discovered that Google will convert megaparsecs to light years–handy!)


After visiting M97 and M108, I had a quick peek at Mars. The red planet is very distant right now, on the opposite side of the sun from us, but it was visibly a disk and not just a point even at low magnification. The disk was most clear at 83x in the 12mm Plossl, but the planet was just flaming in the lousy seeing and I couldn’t make out any details.

Speaking of Mars, our rover Opportunity landed in January, 2004, and is therefore more than nine-and-a-half years into its 90-day mission. Not bad.

After Mars I briefly revisited the Double Cluster, but I could tell that my eyes and brain were no longer operating at anything like peak capacity. So I closed everything down and got a couple of hours of rack. The photo above shows my super-fancy telescope protection system. There are dedicated protective covers for telescopes that will work in rain, sleet, and hail, but hell, if conditions get that bad I will pull the scope inside the car. I didn’t just pack it up because I wanted to do a little birding with it in the morning.


We  did spend some time birding, and then while London got the campfire going, I started packing up. I do have a nice padded case for the telescope en route from Amazon–this one, recommended by David DeLano–but it’s not here yet so I used the trash bags and the packing materials the scope came in.


London stayed busy with the Travel Scope 70, which had gotten a workout overnight on the moon, Jupiter, and the deep sky. I have another post coming about the reborn TS70–stay tuned.


One last thing: Reese’s peanut butter cups make fantastic s’mores, and if you have any left over, they are great in pancakes, too.

All in all,  it was a fantastic night, one of my best–and longest–nights of stargazing of all time. At 3:30 I stopped observing to sit at one of the picnic tables and eat a banana. The stars were so bright and the sky was so full of stuff to look at. When I got back to the telescope, I scrawled in my notebook, “Nights like this make me wonder why I bother to observe anywhere else.”