Archive for September, 2012

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Mt Wilson 60-inch telescope model by Barry Crist

September 18, 2012

I bought a new telescope–my smallest yet.

The 60-inch telescope at Mount Wilson not only played a big role in the history of astronomy, it also played a big role in my history in astronomy (see this and this). So I was happy to get one of the last models of the grand machine made by miniature telescope maker extraordinaire, Barry Crist.

Yes, there’s a mirror down there. Two, in fact–a primary mirror and a tertiary to send the light out the side of the scope to the eyepiece.

There’s the tertiary mirror lurking amidst the faux ironwork. There’s also a secondary mirror up at the front end, but I couldn’t get a clean shot of it. The mirrors aren’t image-forming and the eyepiece is just a painted plug, but still–little mirrors! So cool. And as the photos show, the little equatorial fork turns in both right ascension and declination.

And there’s the maker’s serial number cleverly hidden away at the back of the fork.

Unfortunately, these aren’t available anymore. I got one of the last three, and apparently Mr. Crist has no plans to make any more. There are still a few models of the 100-inch Hooker telescope available, which is made to the same scale as the 60-inch. Details here, while they last.

The miniature 60-inch and 100-inch telescopes by Barry Crist. Photo from the Mount Wilson Observatory website.

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The pilgrimage to Palomar, constellations by DSLR, and the Azusa fire

September 3, 2012

I have been fortunate to visit two of the great research observatories in California: Lick Observatory on Mount Hamilton, overlooking San Jose, which got me into all this in the first place; and Mount Wilson Observatory, where I’ve gotten to observe twice with the 60-inch telescope.

For a long time I have been meaning to get to the third major research observatory in California: Palomar. The building of the 200-inch (5-meter) telescope during the Great Depression was one of the first scientific “megaprojects”, something akin to the Apollo program or the search for the Higgs boson, and it caught the public interest in much the same way. After serious war-related delays, the great machine was finally dedicated in 1948, had its official first light in 1949, and started regular research observations in 1950–a program that continues to this day. The 200-inch telescope was absolutely the world’s largest telescope from 1948 to 1976, and effectively the world’s largest telescope until the first Keck telescope came online in 1993. The 6-meter Soviet BTA-6, which was completed in 1976, was more of a publicity stunt than a functional instrument and has not lived up to its potential, although I hear it is being overhauled so maybe that will finally change.

If you are remotely interested in the history of big telescopes in general and the history of the 200-inch in particular, I highly recommend The Perfect Machine, by Ronald Florence. If I started relating all the interesting anecdotes about the building of the telescope, we’d be here forever–it will be faster and more enjoyable to read the darn book.

Anyway, yesterday I was staring down the barrel of a 3-day weekend with no definite plans. I decided that it was finally time to go see the “big eye” at Palomar Mountain. London and I didn’t get on the road until early afternoon, so we got down there too late to visit the observatory yesterday. Instead, we went to nearby Palomar Mountain State Park for a phenomenal sunset and some early evening stargazing.

I had along a new toy: Vicki loaned me her Nikon D70 DSLR. She’s had it for three or four years, I’ve just never used it. It’s been on my to-do list, though, and Kevin’s results on Mount Baldy a couple of weeks ago gave me just the kick that I needed. I have been waiting not-s0-patiently for the full moon to pass so that I could try my hand at photographing constellations.

London in the meadow by Doane Pond, with the handle of the dipper hanging overhead.

After sunset London and I went down to Doane Pond, which sits in a nice little bowl with mountains on all sides. We went on a night hike around the pond, which resulted in us accidentally scaring several bullfrogs and them scaring us right back–few things are more alarming than an unsuspected animal making sudden noisy movement right by your feet in the dark. I also stopped at various places around the pond to photograph the sky, the pond, or the sky reflected in the pond.

I should preface all this by saying that I have no idea what I’m doing. This is my first time using a DSLR, I have no idea what about 95% of the controls do, and if you actually know photography you’d best put your beverage down now so you don’t spit it all over the keyboard. Nevertheless, I have read that one can get passable constellation photos with exposures of  30 seconds or less, and you are about  to see my first round of results.

I’ve been rereading Leslie Peltier’s Starlight Nights. I think of it, and Timothy Ferris’s Seeing in the Dark (the subject of this previous post), as “books about the why”. Loads of books will tell you how to stargaze, but very talk about the actual thoughts and emotions associated with the practice. If you want to know why to stargaze, go read Starlight Nights and Seeing in the Dark. Just be warned–if you’re not a stargazer now, you may be one by the time you’re done (also, if you’re not, I don’t know what you’re doing here, but welcome!).

Peltier writes with great warmth about his favorite stars, especially Vega, which was the first star he knew by name. I’d be hard pressed to name one favorite star, but I have a favorite constellation, and that is Cassiopeia. When I started getting into astronomy in the fall of 2007–almost five years ago, now–Cassiopeia was the first constellation I learned. All that autumn I turned my gaze northeast at dusk and found Cassiopeia first. She pointed me on westward to Cepheus and Draco and ultimately to Hercules and M13. To the south she led me to Pegasus, Aries, faint and frustrating Triangulum, and of course Andromeda and its magnificent galaxy. And following in Cassiopeia’s train as she climbed the eastern sky I found the Double Cluster and Perseus, the Pleiades, the Hyades, Auriga and its nice trio of Messier clusters, and the constellations of winter. Our romance has only deepened as I’ve gotten to know her better, for the velvety black folds of her dress are adorned with star clusters and nebulae almost beyond counting. Naturally, I pointed the camera in her direction first.

My first constellation photo–click through for the full-size, unlabeled version.

This is not a triumph of astrophotography. It’s grainy, it’s too bright, and the composition is not stellar (to, er, coin a phrase). But Cassiopeia is there, and I even see the Double Cluster just clearing the trees.

After paying my respects to Cassiopeia, I turned south, to Sagittarius and the summer Milky Way. Here’s the best of the lot, without labels.

And the same thing with constellations and deep sky objects labeled. Not every bright deep sky object is labeled, only those where I can see at least a smudge or a couple of bright pixels. Still, there are at least 19 DSOs visible in what was probably a 20- or 25-second exposure.

I am really looking forward to trying this under darker skies. It never got truly dark at Doane Pond, because the nearly-full waning gibbous moon rose well before the end of astronomical twilight. I think that without the moon it would have gotten very dark–maybe not stupid-dark like the remote places in the Mojave, but darker than Mount Baldy.

One more: the Big Dipper over Doane Pond, with a couple of its stars reflected in the pond. The pond was about as still as it could be, given the number of big splashes caused by alarmed bullfrogs (and, therefore, ultimately caused by me!).

Two things you shouldn’t mess with. To truly grok the immensitude of the telescope, check out the normal-size, full-width ladder going up one beam on the near side. The fork arms on either side have stairways inside for servicing the drive motors.

Today we went up to the top of the mountain and toured the observatory. Oddly enough, I don’t have a ton to say about this, beyond the obvious things. Which are (1) it’s awesome, and (2) if you live within striking distance, you should definitely go. Get there in time to get tickets for the guided tour–it’s waaaaay better than the self-guided tour, the docents are friendly and know a ton about the telescope and its history, and you’ll get to go up onto the catwalk inside the dome and get a much better view of the scope than you can from the little glassed-in visitor area on the dome floor. You really need to walk under and around the scope to get a sense of how immense it is, and you can’t do that except on the guided tour. I have been around some big scopes, including the 3-meter Shane reflector at the Lick Observatory, and the 200-inch makes all the others I’ve seen look like toys. Even knowing intellectually how big it is, I still walked in and thought, “OMG that’s big.” It’s inhumanly big.

The only downside to the whole trip is that as I was packing us up to leave, I momentarily set my observing notebook on top of the car–and then forgot to get it before we drove off. That’s a bummer. I have almost all of the observations backed up in my digital observing log (a huge Excel file), but the notebook had lots of sketches and there were probably a few object descriptions that I had not logged digitally. There’s a slim chance it will turn up, but I’m not holding my breath.

One final thing: there’s a wildfire burning in the Angeles National Forest above Azusa. It started just this afternoon. London and I saw it when we were coming home on I-15, as a fat pyrocumulus cloud squatting on the San Gabriels like a big evil god. At sunset I went to the top of the Claremont parking garage and watched it for a while. It must have hit a new fuel source around then because as I was watching it took about 10 minutes to go from this:

to this:

While I watched, I saw and heard several helicopters making runs to dump either water or fire-retardant foam. At that time, the fire had spread to more than 1000 acres and percent containment was zero. I’ve been up in the mountains lately and they’re bone dry, so this could be a bad one. My prayers are with the firefighters, and the people whose homes lie in the path of the fire.

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Lost astronomy notebook

September 2, 2012

This is a crazy longshot, but: I lost my astronomy notebook at Palomar Observatory today. It’s a black 8×5 hardbound notebook, grid-ruled, has an elastic band to hold it shut, and is filled with observing notes up front and hand-drawn maps in back. I left it on top of my car when I left this afternoon (Sunday, Sept. 2). It might have fallen off the car in the parking lot, or half a mile down the road, so this is probably an exercise in futility. Nevertheless, if anyone finds it, I would be happy to reimburse you for your time, trouble, and the postage to return it.

Next up: a post about the actual visit to the observatory.

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Some noodling about my dream scope

September 1, 2012

Fair warning: this post is just me thinking out loud about my dream scope. If you’d rather read about the stars, good on ya–there are plenty of other posts here about that stuff, that will be more interesting than this extended episode of navel-gazing about gear. Feel free to skip backward or–hopefully soon–forward.

As I’ve mentioned here a few times before, eventually I want to have a bigger scope, something in the 14″-18″ range. There are four boundaries that define it:

1. It has to be enough of a gain over my current scope to be worth the expense. Some people say that small gains in aperture are not worth it, that you won’t notice enough of an improvement to make it worthwhile. I have looked through 8″ and 10″ scopes in quick succession, and 10″ and 12″ scopes in quick succession, and in both cases the gain in light gathering and resolution was immediately noticeable at the eyepiece. But it’s the “to make it worthwhile” part that’s the kicker. As we saw in What Aperture Costs, above 10″ prices increase sharply. As long as I’m saving up for my dream scope, I might as well save a little longer and get the wow factor instead of settling for a scope I’ll want to trade up from before long. To really get the wow factor from a bigger scope, most people recommend doubling your light grasp–which for me means going from 10″ to 14″ (78.5 to 154 in^2)–or going one magnitude deeper, a factor of 2.5, which for me means going to 16″ (200 in^2).

2. It has to be small enough to fit in my current vehicle or any foreseeable future vehicle not specifically purchased for hauling around big telescopes. That means it has to be collapsible. But it has to be collapsible anyway, because I’ve had a solid-tube 12″ and didn’t keep it. In that case, the gain over the XT10 was noticeable but not worth it. And it still has to fit in a regular car. My friend Ron has a minivan that he bought specifically for hauling around his 22″, but I will probably never be in the position to base my vehicular purchases around my telescopes.

3. The pieces have to be light enough that I can set it up by myself. My friend Jeff has a collapsible 16″–it’s the scope we took on the LCROSS impact watch–but the mirror box is so damn heavy it takes both of us to get it up into the back of his pickup. I’d prefer a max weight for each piece under 75 lbs, and under 50 would be better still. If those sound like light loads for a healthy 6’2″ dude, go move big scopes around for a while. It’s like moving furniture–awkward weight with a center of gravity far from your body that makes the load on your back a lot worse than when you’re pumping iron. My XT10 weighs 55 lbs assembled. I can move it around in one piece if I have to, but I usually feel it in the morning. A 55-lb chunk of a bigger scope would probably be smaller, less awkward, and hurt my back less.

4. I have to be able to afford it. More specifically, I’d like to be able to afford it with no more than a year or three of saving up. Maybe someday I’ll save for a decade or two and get a custom-made ultralight 25″ that packs into the back of a compact car (such things do exist), but that would be my last scope, not my next scope. For me, right now, given the disposable income I can afford to dedicate to astronomy, the one-to-a-few year saving duration means a one-to-a-few thousand dollar budget. (If that sounds low, hey, congrats, feel free to buy me a scope. I promise to use it for outreach! If it sounds high, go price ATVs or boats or campers or any of the really high-end grown-up toys.)

Those conditions give me a range of options to think about while I’m saving up.

For a long time, my dream-scope ideal was a T-Scope, a custom 14″ truss-tube dob with a low rocker box, starting at $3195. Pros: light, 65 lbs total and heaviest single component is 35 lbs; very high quality, very compact when disassembled. Cons: among the pricier options I’m looking at, cost does not include shipping from New York state (not a jab against T-Scopes, almost no-one has free shipping on scopes like these, it’s just one more thing I have to think about). UPDATE: another con is this negative customer experience reported on CN. I’m going to try to find out more about it–stay tuned.

These days I’m thinking more and more about DobStuff. Dennis Steele makes big scopes that  look awesome, weigh next to nothing, and cost surprisingly little for ultralight custom scopes. A 14″ weighs 70 lbs assembled, heaviest single component is 30 lbs, and goes for $2195. A 16″ would weigh about 90 lbs assembled, heaviest single component 45 lbs, for $3495. Apparently there is a price jump from 14″ to 16″ optics, which explains why the 16″ costs so much more than the 14″. Anyway, super-cool scopes that are pretty much exactly what I’m looking for. One CN member says his 16″ DobStuff has a footprint of 24″x24″ and sits in the back seat of his car when collapsed for travel. I need something like that.

Turning to mass-produced scopes, there’s the Orion XX14i, a 14″ semi-truss dob, starting at $1899. That’s a lot of scope for not a lot of dough, especially considering it comes with digital setting circles (i.e., non-motorized “push-to” object locator). And I could drive to someplace that actually has them in stock and save on shipping. Downsides: compared to the other scopes I’m considering, it’s a pig. I call it a semi-truss dob because although it has trusses connecting the ends of the tube, and they do allow it to break down into smaller pieces, they don’t actually lighten the scope. Orion’s 12″ truss dob weighs just as much as the solid-tube version. The assembled weight is 120 lbs, and the heaviest single component is 55 lbs, as much as my XT10 and almost as much as an entire T-Scope. Also, there’s no way to get the scope without the digital setting circles, and it irks me to know that I’d be paying a few hundred more for a feature I’d happily do without. Finally, there have been some quality control issues; at least one Cloudy Nights user got an optical dud and Orion did not replace it, which is the first time I’ve ever heard of that happening. In fairness, Orion has apparently improved the quality of the optics shipping with the newer XX14s, so maybe–hopefully–the optical disappointments are all in the past.

I discovered as I was writing this post that Orion has just introduced a 16″ semi-truss scope, the XX16g. Apparently it’s just like the XX14i but more so: more weight (195 lbs assembled), more cost ($3599), and more paying through the nose for stuff I don’t need–unlike the XX12 and XX14, which can be ordered in the “i” push-to versions or the “g” go-to versions, the XX16 is so far only available with go-to. So I’d be paying even more money for even more stuff I’d happily do without. I’m sure go-to is nice and if I had it I’d get addicted. My objections to go-to basically fall into three categories: (1) I spend at least half of each day working at a computer. I go stargazing to get away from all that. (2) At any given cost, adding electronics means taking away aperture. Given my limited budget, I prefer to buy aperture, for which there is no substitute, rather than electronics, which don’t do anything I can’t do myself with a star atlas and some elbow grease.* And (3) like all electronics, all go-to systems eventually fail. This is why Uncle Rod recommends buying CATs on equatorial mounts instead of fork mounts–EQ-mounted tubes are a lot easier to remount when the motorized mount craps out. I should say that these are my personal reasons for not wanting go-to for myself. If you have, love, or want go-to, that’s cool–may a thousand gardens grow. No need to sell me on it; it’s just not my scene, man.

* John Dobson says that dobsonian telescopes are held together by gravity and powered by yogurt (you eat the yogurt, and push the scope around with your muscles). Preach it, Brother Dobson.**

** That’s funny, see, because Dobson actually was a monk (before he got kicked out for doing too much sidewalk astronomy).

Meade’s 16″ LightBridge is a contender. At about $2000 it costs only a shade more than the XX14, but delivers a third again as much light. Another way to look at it is that it delivers the same light grasp as the XX16g for a little over half as much dough. The weight is high, but no worse than the XX14i: 128 lbs total, and heaviest single component is 58 lbs. Downsides? From everything I’ve read, the LightBridge series do not  quite match the comparable Orion scopes on build quality. They seem to be “work in progress” scopes. This is especially true of the 16″–I’ve heard of lots of people who have rebuilt the base, which is apparently too wobbly for such a heavy scope, and Dennis Steele at DobStuff offers replacement base kits for just this purpose. When there’s a thriving aftermarket to fix the problems with a telescope as delivered, that’s a problem. I’m saving up for my dream scope, not a project scope. But it’s a lot of scope for two grand; even budgeting an addition $395 for a replacement base, it’s a solid deal.

And it’s an affordable way to lay one’s hands on a set of 16″ optics. I realized something odd the other night. A 16″ DobStuff is $3495, but a DobStuff makeover, where you supply the optics, is only $895 for a 16″, plus another $150 for the Easy Transport Telescope option. So it’s actually about $400 cheaper to buy a 16″ LightBridge ($2000) and have it made over ($1045, for $3040 total) than to buy a 16″ DobStuff straight up. About the only risk I can see is the possibility of variable quality control in the LightBridge optics, although from what I’ve read the baseline quality is quite good and I haven’t read any horror stories.

Two options I haven’t discussed are building my own and buying used. Regarding building my own, see comments above about dream scope vs project scope. And although I am normally a big fan of buying and selling used telescopes, I am a little leery in the case of my dream scope. If this is either going to be my last scope or my last scope for many years, I want to get exactly the right thing. I’ve already taken one poorly-considered leap into larger aperture and regretted it. I don’t want to make that mistake again.

And yet…a used scope could just be a delivery mechanism for big optics. The other day someone on CN was selling a used 16″ LightBridge for $1500, and I have seen them go for even less. That plus a DobStuff makeover could be a faster, cheaper track to my dream scope than going all-new. It’s something to think about, anyway–I’m sure I’ll have plenty of time to consider, and reconsider,  and rereconsider, etc., over the next few months and probably years.