Archive for March, 2017

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Observing Report: more Messiers at the Salton Sea

March 21, 2017

I went to Mecca Beach again Saturday evening. Like my run at the end of February, it was a solo mission, decided on at the last minute. I made up my mind in the mid-afternoon and I emailed a few folks to see if anyone was interested, but that proved to be too little notice (not surprisingly).

I got a late start, didn’t arrive until about two hours after sunset, and there was a cloud bank to the west, so I missed out on all of the early evening Messiers. I skipped right over the winter objects, having spent the last 6 weeks observing them repeatedly with a variety of instruments.

Gear

I’m flying to Texas this weekend for a Messier Marathon star party – more news on that soon – and I’m taking the Badger along. I’ve flown with little Maks and with an AstroScan once, but this will be my first time flying with a refractor. I’ve had this trip in mind for a while – it’s why I was so excited to find that the Badger would ride securely and comfortably on my Manfrotto CXPRO4 plus DwarfStar rig, because that is an eminently flight-worthy mount and tripod combo. BUT the previous testing was just a short session in the driveway. I was curious to see how the Manfrotto/DwarfStar/Bresser setup would fare under semi-realistic conditions, on an extended observing run at a distant site.

I was also testing eyepieces. I want a travel setup that will be lightweight and low hassle, but that will still cover all the things I’m likely to want. My prime mover is the 28mm RKE. It is simply delightful and gives a bright view of a wide swath of sky. Next up is the Celestron 8-24mm zoom eyepiece, which covers most of the useful magnification range for this scope (19x-57x). I used this eyepiece a lot right after I got it. Then I was off it for a while – I went through a phase of doing a lot of high-power work with my Apex 127 and C80ED, and I thought (and still think) that the Celestron zoom was just a hair less sharp than the best of my non-zoom eyepieces, particularly the Explore Scientifics. However, my eyes are now the weakest link in the optical chain, even with glasses. So although I don’t get super-sharp pinpointy star images anymore (or at least, not until I get new glasses), I also don’t worry too much about whether my eyepieces are 100% sharp or only 97%.

I also auditioned some possible third players: the 32mm Plossl, just in case I needed more true field than the 28mm RKE will give; the 5mm Meade MWA for ‘high-power’ work (still only 92x); and the 2x Shorty Barlow. It turns out that I don’t need any more field than the 28mm RKE gives, so the Plossl is staying home; the MWA is nice but big, and not worth the bulk on this trip; and my Shorty Barlow has ever-so-slightly misaligned barrel pieces, so it won’t sit all the way down in the focuser. I’d noticed this before, but it didn’t bother me because all of my other eyepieces would come to focus anyway, but not, it turns out, the Celestron zoom. So the Barlow is staying home, too, and I’m planning to roll with just the 28mm RKE and the Celestron zoom.

Star Testing

I spent the first hour on just four targets: the Trapezium in Orion, the Pleiades, Jupiter, and Polaris. I looked at the Pleiades just to see them before they went down into the cloud bank over Palm Springs. The other three targets were to test the scope and the skies. The seeing was a little better than it has been for most of this spring, but still only so-so. The Trapezium was bouncing around too much for me to resolve the E and F components, although I suspected E a couple of times.

Jupiter looked a lot better than it has so far in this scope. I think that was partly a little better seeing, and partly the result of having collimated the scope. As I mentioned in the last post, the view of Jupiter at 92x was mesmerizing, with finely-divided belts and zones resolved all the way to the poles. I was using the 60mm aperture mask to knock down the CA, and that might have helped with the seeing and with other aberrations.

When I had stared at Jupiter for about 20 minutes, I removed the aperture mask and did a proper star test on Polaris. I’m not an expert at star testing but I know a little, and I have a copy of Suiter’s book, Star Testing Astronomical Telescopes, on loan from a friend in the club. I sketched the results inside and outside of focus and compared them to the diagrams in the book when I got home. The scope has about 1/4 wave of spherical aberration. That’s not great – it’s flirting with being not diffraction-limited, and it helps explain the scope’s so-so performance on solar system objects and double stars. On the upside, the perfectly-concentric diffraction rings confirmed that the scope is now in good collimation.

Binocular Messier Hunting

The best sky conditions of the evening were in the hour on either side of midnight. The cloud bank to the west was still there, but it had retreated down near the horizon. Transparency was as good as it was going to get. Lying down in a lounge chair and looking up naked-eye, I could make out sixth-magnitude stars at the zenith. After spending a good chunk of time at the telescope looking closely at a handful of objects, I was ready for a change of pace. I grabbed the 7×50 binoculars that came with the Bresser Comet Edition package and hopped in the lounge chair for a Messier tour.

I started with some galaxies in Ursa Major. M51, M81, and M82 were all easy, as were M94 and M63 in Canes Venatici. Then I jumped over to Corvus to pick up M68 and M104. After that I went to Coma Berenices and spent a while just staring into the Coma star cluster. It’s a true open cluster, and it looks huge because it is only 288 light years away. That’s farther than the Hyades (~150 light years), but closer than the Pleiades (380-440 light years, depending on the source), and the size of the Coma cluster is nicely intermediate between those two as well.

My first Messiers in this area were the globular clusters M3 and M53. Both were easy catches, and M3 was so bright I had to look twice to make sure it wasn’t a star. Seeing them in binoculars brought back fond memories of the very first time I ever observed them. It was the spring of 2008, and we were still living in Merced. I was on a backyard campout with London, who was only 3 1/2 years old. We were using my old dome tent, and as soon as London went to sleep I poked my top half out onto the grass and did some binocular stargazing. That was the first time I ever saw M3 and M53 with my own eyes.

My next target was the galaxy M64, and it was bright and obvious – so much so that it seemed to pop out from the background, the way that planetary nebulae sometimes do. M65 and M66 were not so pronounced but they were still easy prey. M95, M96, and M105 took a little more work and chart-checking, but I managed to bag them all. Later in the morning, after I’d gone back to the scope, I picked up the globular clusters M13 and M92, and the open clusters M6, M7, and M11.

I know that other observers have seen all 110 Messier objects with 7×50 binoculars – Jay Reynolds Freeman reports having done so in his essay, “Messier surveys“. I’ve seen all of the Messiers in my 15x70s and most of them in 10x50s, but I’ve never even attempted them in 7x binos. So I am working on a proper Messier survey with these 7x50s, and so far I’m up to 40 objects. Here’s my visual log – I’m highlighting objects in green as I observe them:

If you’d like a similar record sheet for your own observations, here’s a blank one:

A Varmint of the Skies

After an hour of binocular observing, I was ready for a stretch, and also champing to track down some of these objects with the scope. I had gotten through most of them with the scope, and I was about to make my assault on the Virgo galaxies when the moon rose.

I thought that contrast had dropped off a bit, and I was seeing fewer faint stars, and the rising moon made the reason clear: a high, thin haze had developed over most of the sky. Galaxies that had been dead easy in the binoculars just an hour before were now completely invisible in the scope. I missed out on M63, M94, and M101, and abandoned my Virgo galaxy hunt. I watched the moon rise through my binoculars, then I switched to double stars for a while. I’m not going to say much about that right now – suffice it to say that the results of my double star observing will be coming to a newsstand near you this fall.

After I’d done my double star ‘homework’, I was feeling very pleased. At the start of the evening I’d written down three goals for the session: “Messiers, double stars, chill”. With the first two activities done to my satisfaction, I was content to engage in the third. I spent more time looking at Jupiter and the moon through the scope, and a fair amount of time just sitting on a picnic table and looking up with my naked eyes. The haze had thinned out somewhat by 3:00 and I was just happy to be out under the stars. Although there were people camped just a few hundred feet from me, I had the place all to myself. Even the coyotes had stopped yipping and howling.

Back at the scope, I spent a while looking around in Lyra. My favorite astronomical axe to grind is that the “celestial sphere” compresses almost limitless space and time into what looks like a dome over our heads. As I put it in this article (and this even earlier blog post), I’m constantly trying to “shatter the bowl of the sky, to see space as space”. Lyra is a good area in which to do this, with objects as close as Vega – a scant 25 light years away – and as distant as the globular cluster M56, which lies 33,000 light years away. I’ll probably write a whole post about that soon.

Usually if I’m up that late at this time of year, I go through the “steam from the teapot” Messiers in Sagittarius and Scutum. But an unfortunate cloud was camped out in my way. I did pick up M11 in Scutum, and M6 and M7 near the ‘stinger’ of Scorpius, with both the binoculars and the scope. I also had a nice long look at the False Comet cluster near Zeta Scorpii. The False Comet is a fantastic object for binoculars and rich field scopes – or maybe I should say “a fantastic set of objects”, since it includes the open clusters NGC 6231 and Trumpler 24, and other bright stars in the Scorpius OB1 assocation, of which both clusters are members.

I’m up to 43 Messiers with the Badger. There are 3 objects that I’ve seen in the Bresser binoculars but not yet in this scope: M63, M94, and M101. And there are 6 that I’ve seen in the scope but not yet in the bins: M5, M29, M39, M56, M57, and M79. I’m not worried about the mismatch – most of the objects I haven’t seen in the binoculars because I just haven’t tried yet. Although I am a little nervous about my ability to distinguish the smaller planetary nebulae from stars at only 7x. Still, it’s a fun hunt and so far I’ve seen almost everything I’ve attempted. Here’s the visual tally for the scope:

I ended back in the solar system. I had a nice long look at Saturn a little after 4:00 AM, and at 4:15 I was gazing at the moon when I fell asleep. After a lifetime in academia, I’m very good at sleeping sitting up, and I didn’t realize I had drifted off until my eyebrow brushed the eyepiece, ever so gently. I think that’s the first time in almost a decade of stargazing that I have actually fallen asleep at the eyepiece. I called it a night, dragged the lounge chair around to the west side of the car where it would be out of the sun, and slept until almost 11:00.

Verdict? Well, the scope is no planet-killer. Doing the star test confirmed what I already suspected. But if I use an aperture mask and keep both the magnification and my expectations modest, it still delivers rewarding views of solar system targets. And it continues to be a fantastic wide field, low power scope for deep sky work. I was also happy to find that the light Manfrotto tripod and DwarfStar mount were more than adequate. I did have to let the scope settle a little at high power, but for Messier sweeping the whole rig just got out of the way and let me observe, which is what I had hoped for. Finally, although I had other eyepieces sitting in the rack, I spent almost the entire evening using just the 28mm RKE and the 8-24mm zoom. So as a test of my travel kit, the evening was a resounding success – and a heck of a lot of fun to boot.

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Collimating a reflactor

March 20, 2017

One of the nice things about ‘reflactors’, like the ones shown here, is that they can be collimated just like reflectors – and at the fast focal ratios that reflactors typically work at, they’re likely to need it.

I don’t think I’ve ever blogged about collimation before. I haven’t blogged about how to do it because there are so many other sites that cover it already. I learned it myself from the book Astronomy Hacks by Robert Bruce Thompson and Barbara Fritchman Thompson, which is a pretty good book for anyone getting started with a telescope, and an absolute gold mine for anyone who owns a reflector. The Thompsons have nice step-by-step instructions, illustrated with photos, for making and using your own collimation cap, and for collimating using the Barlowed laser method.

Collimation is one of those things that seems forbiddingly complex until you’ve done it a couple of times, at which point it becomes so routine as to hardly be worth mentioning. In conversation with other amateur astronomers I usually compare it to changing a baby’s diaper – awkward and probably terrifying the first time or two, and a complete non-event the next thousand or so times.

The Badger and the Ferret both have Allen bolts on the back ends of their OTAs that look pretty much the same as those on the spiders of Newtonian reflectors. The central bolt controls the distance down the tube and the rotational facing of the diagonal mirror, and the three perimeter bolts control the mirror’s tilt. You can use a Cheshire sight tube or collimation cap and collimate a reflactor just like you’d do a reflector. You can also use the Barlowed laser method, which is what I did.

It’s a three-step process:

  1. Draw a set of concentric circles on a piece of graph paper to make a collimation target, and rubber-band this over the front of the scope.
  2. Pop a laser collimator (or any laser, really) into a Barlow lens and see where the beam lands.
  3. Adjust the rotation and tilt of the mirror until the beam is centered.

I did the first bit in my garage, which is why there’s so much crap in the background of the first photo. Then I realized that it would be a lot faster and easier if I could see what was happening to the beam while I adjusted the collimation bolts, so I carried the whole rig inside the house and into the bathroom and pointed it at the bathroom mirror. Once I had the collimation spot-on, I spun the scope a quarter turn to get the final photo, which is why our tropical-themed shower curtain is in the background of the second shot.

As you can see from the photos, the scope arrived a bit out of collimation. That wasn’t a huge deal for the kind of low-power scanning that I got the scope for, but it probably did degrade lunar and planetary images somewhat. I can tell you that after collimation, it does better. I got a mesmerizingly good view of Jupiter Saturday night at the Salton Sea, with gently ruffled belts and zones marching all the way to the poles, like the layers of crust in a good baklava. But that’s a story for another time.

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Why I blog – and observe, and do everything else – so unevenly

March 13, 2017

[Warning: this is by far the most navel-gazey thing I’ve ever posted here. It’s almost entirely autobiographical, and unless you are really interested in the answer to the titular question, I recommend going elsewhere. Proceed at your own risk! – MJW]

Let’s start with the obvious fact that I do do these things unevenly. I’ve noted this before. I’ll have months where I’m out almost every clear night, and months where I never go out at all, even in good weather. Admittedly those zero-observation months are way down now that I have a monthly column to feed, and one of the things I like best about having a monthly column is that it forces me to get out and observe.

The why of this is complicated. Partly it is a complex and seasonally-shifting work schedule. Except for a couple of weeks between terms in August, and a week here or there for fieldwork or a conference, I teach human gross anatomy every weekday between mid-June and the end of October. November through May is given over to research and writing, committee work and other forms of administrativa, and prepping lectures for the next teaching block.

Layered over that is the waxing and waning of enthusiams that I think is natural for most people. As my friend Mike once put it in an email, “I know from many, many years’ experience (in programming as well as palaeo) that my phases of enthusiasm drift in and out of being in a totally random way, so I need to seize each one as it comes past and squeeze it till it bleeds productivity.”

I feel that, strongly. Very strongly, in fact. There are times when Subject X is all I can think about. It literally keeps me up at night. And then a few weeks or months later, I’ll only be able to think about Subject X with an immense act of will, and little to no enthusiasm or enjoyment. These periods of fascination typically last 4-6 weeks, after which I’ll have two or three days of feeling restless and bored as I cast about for the next thing. They also vary in intensity – sometimes Subject X is just something I think about in my spare time, and sometimes it’s about all I can think about during my waking hours. Privately I refer to these things as my ‘manias’, but a therapist once told me they were more likely to be properly classified as obsessions. Although I remain undiagnosed, I assume that there is some behavior spectrum on which I am a few paces farther away from the mean than most people. (If you have some relevant technical knowledge, I’d love to hear from you in the comments, or by email.)

Subject X can be just about anything. I don’t know in advance what the next one will be, and I don’t pick them. Certain subjects come around repeatedly, and other don’t. For a brief period in the mid-2007 it was houseplants. We went from zero houseplants to about 20 in the space of a month. I’ve managed to kill all of them except one over the following decade, and that particular mania has not returned.

Fortunately for my career, the interest that has returned the most often and at the greatest intensity has been paleontology, and biology more generally. It is not an exaggeration to say that my career has primarily been built on work I got done when I was in the grip of a mania. This worked really well in grad school, before I was a parent and when I had few real responsibilities. I could hole up in the spare room and work for 12 or 16 hours a day, emerging only for meals and bathroom breaks, and go to bed happy and fulfilled and ready to repeat the process the next day. Then I’d have months-long doldrums in which I got nothing done.

Even when I’m ‘on’, it’s a lot harder to channel that level of energy and enthusiasm when my days are so broken up by the spectrum of family and work responsibilities I have now. I’m not complaining about the latter! Being a parent is the most fulfilling I’ve ever done by a long shot, and I am fortunate to have work duties that are interesting and rewarding. If anything, I’m not complaining about my present situation as much as I am pointing out how far I got on very little discipline, because I was able to crank out lots of work in very little time. Even now, many of my papers have their genesis around 2:00 AM, when I can’t rest because I can’t stop thinking about a particular problem, and writing about it is the only way I can exorcise it, at least enough to get to sleep.

So, about this blog. Sometimes stargazing is Subject X, and sometimes it isn’t. The first time was in 2007, right after the houseplants. If the houseplant mania had returned and astronomy had not, I’d probably be blogging about plants on an equally erratic schedule. Because even when I’m in the grip of a mania, I don’t always have the desire or time to blog about it. Activity on any of my blogs is like a spring tide, which requires both the major driver (the moon/a mania for that subject) and the minor driver (the sun/interest in blogging) to align. Except for the first couple of years of SV-POW! when Mike and Darren and I were trying to actually trying to get at least one new post up every week, I have always felt that my blogs existed primarily to serve me, rather than the other way around, and I would blog when I felt like it and not push myself to blog when I didn’t. That’s not to say that I don’t care about my readers. I do, and I’m very grateful for all of the kind things people have said in the comments over the years. I wish I had the capacity to write for you more regularly. I guess I do, you just need a subscription to Sky & Tel to see it.

With all of that said, there are certain conditions that tend to push me toward stargazing. I typically do a lot of stargazing in the summer (up on Mount Baldy) and early fall (out in the desert), partly because the weather is nice, and partly because teaching anatomy is sufficiently technically demanding that I don’t have much energy or enthusiasm left over for paleontology, and I’m actively looking for something very different to do and think about. Stargazing versus teaching anatomy: outdoors vs indoors, alone or in a small group vs being in a lab with 50-150 people, no pressure vs trying hard to get everything right, on my own time vs scheduled. It’s the perfect getaway from my day job.

Likewise, I’m blogging a lot right now in part because I have a whole stew of stuff keeping me busy at the university, including some demanding committee work. And in part because I realize that these ‘spring tide’ events of stargazing mania, desire to blog, and time in which to do so don’t come around very often, so I’d better get as much done as I can before conditions change.

And they will change. My ever-cycling interest will turn to something else. In a few months we’ll have a beautifully clear evening and I’ll see the scopes in the garage and do nothing with them because I will feel nothing. I am fully cognizant of this now, and I will be fully aware of it then, but that knowledge will not motivate me. I simply will not care about stargazing, and I’ll go do something else instead. All of the subjects that fascinate me are tinged with this Flowers for Algernon-esque bittersweetness. But I rarely think about that – I’m usually too busy thinking about the current mania.

I have wondered, if this whatever-it-is that I have is ever diagnosed, and a treatment offered, if I would accept it. Sometimes it would be nice to be able to think about what I want, instead of whatever semi-random subject has a hold on my mind at the time. But I don’t think I would give up the exhilaration of these obsessions for mere convenience. I have previously compared them to falling in love, and when you are madly in love, there is no number of ordinary friendships that you would accept in trade.

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Young crescent moon, pleasant surprises, the Bresser gets a name

March 1, 2017

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Got out tonight for a few short burst of observing amidst other things. I set up the C80ED and caught the young crescent moon as it was going down. Above is my best shot. It is still wildly inferior to the one I have up in the banner image, to the right of the blog title. That one I shot with my XT6, which had about three times the light gathering ability and almost twice the angular resolution of the C80ED, and I got that shot one night earlier in the lunar cycle. That was back in the early days, when we were still living in Merced. From my driveway I had a straight shot almost to the horizon, so I could catch a 2-day old moon. Here I have lots of trees and buildings in the way, so I generally have to wait an extra night to get a shot at the moon from the driveway.

Then I was out again in the half hour before midnight to try some things with the Bresser Messier AR102S Comet Edition. First, I put it on the lightweight Manfrotto CXPRO4 tripod and DwarfStar alt-az mount that I have previously only used for much smaller scopes (example 1, example 2). Orion was going down over LA so it was pretty stinky, but I still had a long look at both the belt and the sword, and I powered up to split the Trapezium and Sigma Orionis. Then I swept up to hit M35 in Gemini, then back down to Meissa at the ‘head’ of Orion. I finished on Jupiter, using the 60mm aperture mask to knock down the CA.

bresser-on-dwarfstar-1

I was deliberately bouncing around the sky, looking at a variety of targets at a variety of magnifications, to see if the Manfrotto/DwarfStar combo would keep up. I’m a pretty forgiving observer – witness my near-pathological devotion to cheap scopes and stuff made out of junk – but one thing I just can’t handle is an undermounted scope. My first Mak was a 4″ which I hated and sold away before I realized that I hated it because I’d never put it on a solid mount. That experience left me traumatized when it comes to rickety mounts.

The Bresser/Manfrotto/DwarfStar rig doesn’t look like it should work. It looks like the definition of a spindly undermounted disaster. But it was fine. I never had any problem slewing, tracking, or focusing. It helps that the Bresser is lighter than it looks, and carbon fiber is a lot stronger than it looks.

(In the photo, I have the optional eyepiece rack attached to the DwarfStar – I don’t think I’ve ever shown a photo of the mount with it in place. It’s useful.)

I was also pleasantly surprised by the views I got of Jupiter. To get to a decent magnification I used the 8.8mm ES82, both natively (52x) and Barlowed (104x), and a Celestron 8-24mm zoom dialed down to 8 (57x). In both eyepieces I could see the North and South Equatorial Belts and stacks of minor belts marching away toward the poles. There was some CA, but I could minimize the effect by keeping Jupiter in the center of the field, and my eye centered over the eyepiece. The view was so good that I slipped out of gear testing mode and just stared for a few pleasant minutes. I was also happy to find that with the rubber eyeguard removed, I could see the entire field of the 8-24mm zoom at all magnifications while wearing glasses. Which I have to do now. In fact, the other night at the Salton Sea I made almost all of my observations with glasses on.

And lastly, the Bresser Messier AR102S Comet Edition – whew! – finally has a name. I posted on Cloudy Nights about the Messier survey I’m starting with it (thread here), and CN user ‘Glob’ wrote,

mwedel, I read and enjoy your blog, let me suggest nicknaming the 4″ “The Ferret” as King Louis XV called Messier.

I responded:

That is a lovely suggestion, and it put a huge smile on my face. One thing I haven’t blogged about yet is that basically by serendipity I managed to pick up an 80mm prototype of the Bresser ‘reflactor’. So now I have two, big and little, otherwise nearly identical. Ferrets are mustelids (weasel family), along with wolverines, badgers, skunks, fishers, martens, stoats, weasels, and otters. My late grandfather was an accomplished taxidermist and one of his stuffed badgers is sitting on top of a bookcase about four feet from me as I type. It’s just about the same size as the 4″ reflactor. So I’m going to take your charming suggestion, with one modification: the 80mm will be the Ferret, as I anticipate some effort to ferret out all the Messiers with it, and the 4″ is henceforth the Badger, because it can just knock them around with all that aperture. Thanks for helping me solve that long-standing and vexing problem!

So, it’s official now: from now on, the Bresser AR102S is the Badger, and the 80mm will be the Ferret. More info on the Ferret one of these days. I’m going out with this family photo of the two – Badger’s up front, Ferret looms behind:

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