Observing Report: Comet PanSTARRS by naked eye!

Last night London and I joined fellow PVAA members Ron, Joe, and Steve up on Mount Baldy to watch for the comet. We spotted it fairly late, at least compared to the other night in Claremont when I first saw it at 7:25 PM. Up on the mountain we didn’t see it until 7:45, but I think it was visible sooner, we were just looking in the wrong place. We didn’t see the comet sooner because we were looking too far south and too close to the horizon. On the other hand, that’s not a bad problem to have, because when did finally spot it, it was higher in the sky than any of us expected, so we got to watch it for a good long time before it got too low to see. We finally lost it in the murk over LA at about 8:15.

Some people go up to our observing spot just to watch the sun set, and last night was no exception. While we were waiting for the sun to set, I was able to show a couple of people the waxing crescent moon and Jupiter and the Galilean moons. Unfortunatelly our guests gave up and left just about 5 minutes before we spotted the comet. Still, they were very excited by the views of the moon and Jupiter. After the comet set, London and Ron and I spent a few minutes looking at bright Messier objects:  the Pleiades, the Orion nebula, and the  galaxies M81 and M82 in Ursa Major. We had another look at the moon and Jupiter and wrapped up at 8:40.

So it was a short session, but a good one. And, as the title indicates, once it got dark enough we could see the comet with our naked eyes. It wasn’t just a bright dot in the sky, but very slightly elongated, like a tiny dash or comma. In the telescope it was fantastic, with a bright, well-defined tail that stretched out for almost half a degree even in the twilight. I tried to get some pictures with my camera, but there not enough contrast between the comet and sky to get any decent results. I will sketch it one of these days.

The comet will only get higher in the sky (for northern hemisphere observers, anyway) in coming weeks and months. At the same time, it’s going to get dimmer–it’s at max brightness right now. But the light fall-off isn’t going to be crippling. Next month the comet will be a magnitude or so dimmer, but it will also be a LOT higher in the sky, and I think the latter effect will outweigh the former. So I’m expecting even better views of the comet in weeks to come.

Observing Report: the accidental Messier Marathon

Saturday night London and I went camping at the Salton Sea, and I took another stab at a Messier Marathon.

I did basically zero prep. I didn’t even think about checking the weather to see if camping was possible until noon on Saturday. Normally for a marathon attempt I have custom charts and checklists printed and I’ve been boning up on the positions and IDs of all the Messier objects for a few weeks. This time, nada. I have a laminated card with all the Messier objects plotted that I keep on my clipboard, and I took along Harvard Pennington’s The Year-Round Messier Marathon Field Guide (which everyone interested in deep sky observing should own), but my object checklist was handwritten because we don’t have a printer at home and I didn’t have time to go find one. That pretty much tells you all you need to know about my level of readiness.

Gear

I was rolling with new kit this time. In fact, I’ve rolled with different kit every time I’ve attempted a marathon. In 2010 I used my XT6, which was still my biggest telescope at the time. For my first attempt in 2011 I used “Stubby Fats”, a 5″ f/5 reflector I sold last year. For my second attempt in 2011 I used the XT10, which is still my big gun. Oddly enough, I didn’t make a marathon attempt last year; I can’t remember why not.

Yes, that is an eyepatch hanging from the SV50.

This time I used my new tandem rig: my Apex 127 Mak with my SV50 refractor mounted alongside as a deluxe finder. This idea, of having a small rich-field scope mounted alongside a planet-killer, has been a gleam in my eye for a while. I toyed around with DIYing it, but the whole point was to get a rig that Just Works. My adventures in ATMing having convinced me that while some folks can build things that Just Work, I get that level of performance from someone else’s quality control. The first component was a set of 144mm inside diameter tube rings to hold the Apex 127 OTA. That let me rotate it so the finder dovetail faced straight sideways. The second part was a set of actual Stellarvue finder rings. These are crazy nice–the adjustment screws are metal, but with little nylon inserts at the tip so they won’t scratch the telescope tube.

I got this all assembled last year, but right at the end of my fall observing season, so I only used it once, which was the Oct. 20-21 Salton Sea run with David DeLano. Although I haven’t blogged about before now, I have actually gotten out a couple of times this spring, and so far I’ve been using the Apex 127/SV50 setup exclusively. I’m sure the XT10 isn’t out of a job–it can still pull down four times as much light as anything else I own–but the tandem rig is so convenient and flexible that I think it will probably be my default observing setup for the foreseeable future.

Evening Rush

The evening rush was a little stressful. Partly because I was rusty and I knew it, partly because I was worried about the weather, and partly because we were hungry. On the weather front, it was cool and cloudy here in Claremont and indeed all over southern California on Saturday morning. Weather Underground was predicting that it would clear off at the Salton Sea, but only just in time for nightfall, and I have seen things get foggy there fast. Happily the clouds did open up as we drove past Cabazon and out of the LA basin, and by the time we got to the campground there were just a couple of small stragglers left.

I was hungry because in keeping with the rest of the late decision to go and near-total lack of planning, we got to the sea just as it was getting dark, so we didn’t have time to get dinner on before I had to go catch the early-evening objects. I wasn’t so worried for myself, but I felt bad making London wait on dinner while I tried to track down faint fuzzies. Fortunately we had some snacks along to tide him over, and he’s pretty self-directed when he has free time and room to roam.

In the actual event, though, I did get all of the evening rush objects. The toughest were M110 and M74. M110 was tough because I’m not still not used to the upright-but-left-right-reversed view through the Mak, and it took an embarrassing amount of faffing about to find it. M74 is legendarily tough: a fairly faint galaxy that is the closest Messier object to the horizon during the spring marathon season. I did finally find it, thanks to the detailed finder charts in Pennington’s Field Guide, a lot of looking, all the dark adaptation I could muster on short notice, and strategic ue of averted vision. I finally spotted an extremely dim glow, but I couldn’t hold it even in averted vision. I noted the position of the suspected glow with respect to some field stars and switched eyepieces. I fine-tuned my aim, looked away from the target point, and caught the glow in the same spot in averted vision. That’s all I needed.

A Second Evening Rush

By 7:40 I’d caught the eight evening rush targets and bought myself some breathing room, so I knocked off for a bit. London and I cooked some hotdogs over the campfire and got our camp arranged a bit more satisfactorily. We’d pretty much just been throwing stuff around when we first arrived, so I could get set up and start logging objects.

My second session was short but extremely productive: between 8:36 and 8:52 I logged 17 objects. After a short break, I nailed M52 at 9:06, and bought myself a long break. Time for toasted marshmalllows, s’mores, and curling up together in the lounge chair to look for shooting stars and tell stories.

London with the Orion 20×50 compact spotting scope he got for his birthday. More on that scope in a future post (but if you’re impatient, it’s solid).

The Long Mid-Game

London sacked out a little after 10:30 and I got back to work. There were really only three notable mid-game events. First, it took me 17 minutes to get through the 16 galaxies in Virgo and Coma using only the scope–one more minute than last time, when I used only binoculars. Second, at some point in the early morning I got my first look at Saturn this year. The seeing was rotten, but it was still breathtaking. Third, a little after three I noticed that Centaurus was over the horizon so I grabbed the binoculars and swept up Omega Centauri, by far the largest of the Milky Way’s known globular clusters, which is atmospherically dimmed at this latitude but still a majestic sight.

Except for a couple of shortish breaks, I was observing pretty steadily from about 11:15 to about 3:45. I pushed much farther into the morning rush objects than I usually do before I took my siesta. When I knocked off at 3:40, I had 104 objects logged, so I was already in personal best territory (my previous record was 103, from late April, 2011). I figured I could afford 45 minutes of rest while the last few objects crawled over the horizon, so I set my alarm for 4:25 and got flat. As usual on marathon siestas, true sleep eluded me, but I did at least drift a bit.

Morning Rush

Aye-yi-yi. Somehow I always underestimate just how brutal the morning rush is. When I got up and got myself sorted, my first target was M15, which was dead easy. M75 didn’t put up much of a fight, either. But then I went into Capricorn, after M72 and M73. M72 is a glob, like M75, and theoretically it shouldn’t have been that hard, but no matter what I tried I just could not see it. Maybe the atmospheric extinction near the horizon was just worse than I thought, because I had the scope bang on the exact spot, but there was nothing in the eyepiece.

At 4:50 I noticed something alarming: the sky was getting noticeably brighter in the east. Not good! I popped down to M73 and got it easily. Then I started trying for M2, which was right behind a palm tree, so I started waltzing the scope around in what was now obviously getting on toward dawn. Fortunately M2 is pretty bright and it was an easy catch at 4:57. It was also my last catch. I did one last scan for M72 and took a token pass at M30, but neither were showing, so that was that.

Post-Game

I ended with 108 objects. I logged 72 objects only with one or both telescopes, 19 with binoculars only, and 17 with both the bins and one or both of the scopes.

How do I feel about the outcome? Well, there is no question that I could have logged M15 and M2 earlier than I did, which would have left more time for M72 and M30. Maybe if I hadn’t felt rushed I could have brought the full suite of techniques to bear on M72 that I did on M74, but the fact is that I was in a hurry and scattered and just less methodical. Whether that would have helped or not, I don’t know. It certainly woulnd’t have hurt, but I seriously wonder if the sky conditions were good enough. March 9 is pretty early in the season for a marathon–according to Harvard Pennington, the very best chances are new moon nights between March 30 and April 3, which obviously don’t happen every year. This early in the season, all the evening rush objects are higher in the sky and therefore easier, but the morning rush objects are lower and therefore harder. (How much difference does that make? Well, there are 12 months in a year, so if I try again next month, everything will be 1/12th of the way around the sky, relative to the sun, from where it was this weekend. That’s a lot of celestial real estate.) I think M30 was probably impossible, this early in the season and given the imperfect near-horizon sky conditions–but I’d kill to have gotten on target for a try before the brightening sky made it a definite impossibility.

Still, I am pretty darned happy. I missed getting the full slate of 110, but I didn’t miss it by much, and 108 feels much more like Messier Marathon success than 103 did. Heck, the guys who invented the Messier Marathon were stuck at 108 for a year (1979) and then 109 for several years before they finally sealed the deal in 1985 (for more about that history, see Pennington’s Field Guide and this awesome page). I feel like I’ve graduated into the ranks of Marathoners who have only been beaten by the legitimately gnarly nature of the quest.

And I’m spoiling for a rematch. April 6 will be close enough to new moon as makes no difference, so if the weather is good, maybe I’ll get another crack at bagging the whole enchilada.

The tape stripe marks the balance point of the whole rig with eyepieces and without lens caps, so I can mount it correctly every time.

Gear, Redux

I used binoculars a lot less this year than in previous marathons. That’s down to two things. First, I forgot my 15x70s, so I was rolling with the old Celestron 10x50s that I now keep in the car on a permanent basis. They’re fine, they just don’t pull in nearly as much light as the 15x70s, and they lose some attractiveness for that reason. Second, having the SV50 mounted alongside the Apex 127 was like having a high-end binocular I could park. I was using the 23mm eyepiece that came with the scope, so only 8.9x, but I often could see things in the SV50 that I couldn’t see in the 10x50s, so as the evening wore on I gravitated more and more to using the SV50 and skipping the bins entirely. I’m super-happy with the tandem scope setup; it is working out exactly as I’d hoped.

Where You Been, Flake?

Not-quite-finally, I’m sorry to those of you who have commented or emailed lately and not gotten a response. Paleontology has kept me cuh-ray-zee busy this spring, as it did last spring–my coauthor Mike Taylor and I had a paper published last month (free to read here), we have another due out any day now, and we have two more due to the publisher at the end of this month. So that’s where I’ve been. I am sorry for going so completely AWOL and especially for falling behind on my correspondence. If you’re a regular, thanks for not giving up on 10MA while I’ve been on hiatus (and if you’re new here, welcome, and expect periodic delays!).

Welcome to the Club!

Really finally, there’s a new addition to the blogroll on the sidebar. The Thwarted Astronomer is the stargazing blog of my friend Fiona Taylor (spouse of the Mike Taylor I do dinosaur research with and blog with), who lives in England, in the village of Ruardean, near the border of Wales. I have been to Ruardean to visit Fiona and Mike many times, and I can attest that their skies are freaking amazing, when (operative bit) there are no clouds. Which is not often. So, long story short, Fiona has caught the astronomy bug, but the lack of observing opportunities is getting her down. Since we have some regulars here who probably have it even worse, like Doug Rennie up in Oregon, I was hoping maybe y’all could cheer her up.

All right, that’s it for now. See you back here before another month is up, I promise.

Observing report: the compleat stargazing session

Saturday night London and I met up with David DeLano at the Salton Sea for an evening observing session. In thinking about how to describe it I decided that it was the compleat observing run–and yes, I mean compleat, meaning total or quintessential, not ‘complete’.

For one thing, we observed almost every class of object out there: artificial satellites, meteors, the moon, a planet and its moons (Jupiter), a comet (Hergenrother), double stars, asterisms, planetary nebulae (the Ring and the Dumbbell), a supernova remnant (Crab Nebula), bright diffuse nebulae (M42 and M43 in Orion), binocular associations (Alpha Persei Association and Hyades), open star clusters near (Pleiades) and far (M35-38, among many others) and very far (NGC 2158), a very dense open cluster (M11, the Wild Duck cluster), a very sparse globular cluster (M71 in Sagitta), a showpiece globular (M13, the Great Glob in Hercules), a non-Messier glob (NGC 288), Local Group galaxies (M31 and M33) and satellite galaxies (M32 and M110), and at least one non-Messier galaxy (NGC 253, the Silver Coin). Okay, so we didn’t track down any asteroids, terrestrial planets, dark nebulae, Milky Way star clouds, or galaxy clusters. Still, I think we did okay for a sunset-to-midnight run, especially considering we had no fixed plan beyond “hang out and look at stuff”.

Also, we used almost every class of common astronomical instrument: naked eyes, binoculars, doublet refractors (David’s Galileoscope and my SV50), a triplet refractor (David’s SW100T), a Newtonian reflector (London’s Astroscan), and a catadioptric scope (my Apex 127 Mak), in apertures from two to five inches and focal ratios from f/4 to f/12.

We spent a lot of time just looking up. We used whatever instruments we had to hand, on whatever targets were of interest. We used rich-field scopes on solar system targets and planet killers on the deep sky and located faint nebulae with binoculars. We compared views, compared eyepieces, and compared objects. We found new stuff, checked maps, and got lost–yes, both of us. We explored. We rocked.

I did not log any new Herschel 400 objects. I did have a fantastic time. In the future when I am looking forward to an observing run, my standard will be, “I hope it’s as much fun as that one night at the Salton Sea with David”.

I’ve done a LOT of observing this month, with two Mount Baldy runs and overnight trips to Joshua Tree, the All-Arizona Star Party, and the Salton Sea. Also, I’ve been fortunate to get to observe with three of the 10MA regulars in that time (David DeLano, Terry Nakazono, and Doug Rennie). Partly I’ve been making up for lost time, since it was too darned hot to go camping before October this year, and I was too busy in previous months anyway. It’s going to wind down now for a bit, though–this coming weekend I’m out of town, and three weekends from now we’ll be celebrating London’s 8th birthday.

I’ve been in a reflective mood already, as I passed my fifth anniversary as a stargazer and as I approach my 400th observing session. That really kicked into gear when Richard Sutherland asked me in a comment if I had any big plans for the next five years. I’m not ready to tackle a subject that big just yet, but I have learned a few things in this month of crazy observing:

1. The moon is not nearly as much of a hindrance to deep-sky observing as I used to think. Yes, it gets a lot darker when the moon goes down–David and I were both struck by this Saturday night. But Doug and I swept up a ton of faint fuzzies in binos and in his SkyScanner despite a moon only about three days from full.
2. Two inches of aperture will take you crazy deep under dark skies. By using every trick in the book–fanatical dark-adaptation, staying up past midnight (when most folks turn their house lights off), observing at the zenith, waiting until after a rain had swept the crud out of the skies, and mildly hyperventilating–I was once able to spot M1, the Crab Nebula, from my driveway using my 15×70 binos. At the Salton Sea two nights ago, it was dead easy in direct vision in the 10x50s, and in our 50mm finder scopes. M32 and M110 were also dead easy in the Galileoscope, and more difficult but still doable in the binos, with the difficulty mainly down to lower magnification and therefore smaller image scale.
3. With the right eyepiece, the XT10 is a pretty decent rich-field scope. I got the XT10 back in 2010. It came with a 2″ focuser, but until this summer I had not invested in any 2″ eyepieces; I was loathe to spend any money on an eyepiece that I could only use in one scope. But this summer I caved and bought a 32mm Astro-Tech Titan. With a 70-degree apparent field, it gives a true field of almost two degrees in the XT10–enough to frame the Pleiades, the Double Cluster, the Andromeda Galaxy and both satellites, or the entire sword of Orion. That is an 80% gain in the area of the true field of view over my widest 1.25″ eyepiece. David DeLano also has one for his SW100T and it is a fantastic eyepiece in that scope as well. The 32mm Titan normally runs about $80, and IMHO it’s a steal at that price, but right now it’s on sale for closer to $60. If you have a scope with a 2″ focuser, what are you waiting for?
4. For regular camping, a scope you can pick up and move around is highly desirable. At both Joshua Tree and the Salton Sea, I was happy to have the Apex 127 along, because I could just pick it up and move it to get away from local lights or trees. I will have to keep this in mind in contemplating future scope purchases. I have to admit that I am interested in the Celestron C8 SCT, partly for historical reasons, partly because it is the biggest scope that will ride comfortably on my SkyWatcher AZ4 mount (= Orion VersaGo II), and partly because it is probably the biggest scope I could just pick up and move around without a second thought. I reckon I’ll have the Apex 127 forever, though, even if I get a C8 someday, for the same reason that I’ll keep the XT10 if I get a bigger dob–for what it does, it’s just about perfect.
5. Accessories matter. For the first time ever, I have spent more money on accessories than on scopes this year. This summer I went nuts and bought some nice eyepieces, and I just ordered some tube and finder rings and a dovetail for the Apex 127 and SV50. Observing is a lot easier when stuff Just Works, and most telescopes Just Work better with better accessories–sturdier mounts, better diagonals and eyepieces, more convenient finders, and so on.
6. My interests are changing. I’ve only done a handful of comet sketches, but I’m digging them. I’m getting kinda excited about the idea of sketching deep-sky objects. I’m also getting more interested in trying to understand the 3D structure of what’s out there. Before this past month, I hadn’t done any serious binocular astronomy in over a year, and it’s really been great to get back to that. I have no idea where I’m going yet, but it is probably going to involve a lot more than tracking down the next hundred LTGs*.

* Little Turd Galaxies.

The most exciting development in the past month? The morning after the All-Arizona Star Party, Jimmy Ray said that London was pointing his Astroscan around with sufficient skill that he could probably earn a certificate at next spring’s All-Arizona Messier Marathon (certificates start at 50 objects). I had not even considered this possibility, but I discussed it with London on the drive home. Actually being able to find stuff with his telescope the past two weekends has been very empowering for him, and he wants to give it a shot, so we’ll probably start practicing in the coming weeks and months. Fingers firmly crossed!

Observing Report: My fifth anniversary at the eyepiece

Moonrise on Mount Baldy, Oct. 3. Photo by Agnes Kwon.

Last Wednesday evening was the fifth anniversary of my first light with my first telescope. On Oct. 3, 2007, the UPS guy dropped of a big box with an Orion XT6 inside. I built the scope on the living room rug, used a distant water tower to get the finder aligned, and waited impatiently for nightfall. The first object I pointed the scope at was Jupiter. I’d already seen Jupiter and all four Galilean moons with binoculars, but the view in the telescope was indescribably better. I could see cloud belts and colors and details I would not have thought possible. After Jupiter I turned the scope to the Andromeda galaxy and let my eyes collect photons that had been travelling for 2 million years. My final object for the night was the Pleiades, which just barely fit in the field of view of my low-power eyepiece.

One thing I have always been glad of is that I started keeping an observing log from the get-go. It’s an Excel file with date, time, location, instrument(s), objects observed, and notes from every binocular or telescopic observing run since that first one. It runs to 2297 rows now, with notes on all 396 of my observing sessions to date. I was kind of hoping that my fifth anniversary in amateur astronomy would coincide with my 400th observing session, but I’m not quite there yet.

It’s a fitting time to reflect on all of the amazing things I’ve seen in the past five years–and to ponder all of the wonders I have yet to see.

Waning gibbous moon, photo by Agnes Kwon.

A couple of months ago I made a list of my favorite observations of my observing career so far. Heading the list are the annular eclipse and the Venus transit from earlier this year. Other highlights include seeing the gegenschein at the All-Arizona Star Party in 2010, watching the crescent moon pass in front of the Pleiades from the Salton Sea, and tracking a comet as it moved against the background stars, with fellow PVAA member Steve Sittig up at the Webb Schools (never got around to blogging that one–shame). These were all fantastic things to witness with my own eyes. Each one is engraved indelibly in my memory. Probably the most moving was seeing the little black dot of Venus crossing the face of the sun, and knowing that that tiny dot was a world, and not jut any world, but a twin of Earth. It was a profound–and profoundly odd–experience.

I’ve learned a lot about observing itself in the past five years. I know my way around the sky pretty well. I know that if the night is sufficiently clear and if I’m fanatical about dark-adapting my eyes, I can see the Crab Nebula with 15×70 binoculars from my driveway. After buying and selling lots of telescopes, I’ve learned what telescope I have is way less important than how I use it–and mainly, just that I use it.

And most importantly, I’ve learned that I am a social stargazer. If there is a common thread that ties together all of my favorite observations, it’s that they were shared with others–sometimes a whole crowd of people at a public outreach, and sometimes just one or two friends in the dead of night in the middle of nowhere. Oh, I’ve spent plenty of nights at the telescope alone, and those solo vigils are often how I get away from it all. But the “Aha!” moment of discovery is reduced to a dim shadow if there’s no-one there to share the “Aha!” with.

iPhone photo by Chad Claus, shooting afocally through my Orion XT10 with a 32mm Plossl eyepiece.

So it’s fitting that last Wednesday night I went up Mount Baldy with a group of friends and spent the evening stargazing. Most of them are new to observing so I gave them a quick tour of some late summer and early autumn highlights. I didn’t see any objects I hadn’t seen before, but it would be a mistake to say that I didn’t see anything I hadn’t seen before. The way that the Wild Duck Cluster just resolves into a dense swarm of seemingly tiny stars at 120x, or the Galilean moons of Jupiter stacked in an almost perfectly vertical line just above the horizon, are sights that I will not soon forget. And even overly familiar objects take on new life when you see them for the first time through the eyes of another–something I first learned as a parent, and am learning again as a stargazer.

As I look to my next five years as an amateur astronomer, I am thinking about what’s next. And that means not just whether or not I’ll get a bigger, nicer telescope, or what observing projects I’ll take on during that time–it also means who I’ll share those observations with, and what we’ll see together.

I can’t wait.

Observing Report: a semi-cloudy night at Joshua Tree

My scope at Joshua Tree Saturday night. Clockwise around the scope are the bright star Capella just in front, the constellation Perseus (12:00), the Pleiades (2:00), the Hyades (V-shaped arrow of stars directly oppose Capella), and Jupiter (4:00). Photo by Kevin Zhao.

Saturday evening I was at Joshua Tree. My summer anatomy students invited London and me along to the Indian Cove campground. I didn’t have room in the car for the big gun so I took my 5” Mak, which is what it’s for—times when I need a decent amount of aperture in a small package. That was no loss: the sky was striped with high, thin clouds all night and never really cleared out. We got decent views of a few things, but the 10” would have been wasted. We used the Mak to look at the Double Cluster and Jupiter. In moments of steady seeing there were quite a few cloud belts showing, and all four Galilean moons were lined up on one side of the planet, which was pretty cool. London brought along his AstroScan and we used it to look at extended objects like the Pleiades and the Andromeda galaxy.

iPhone panorama by Chad Claus. Click for the big version!

The clouds might have made for lousy telescopic views but they made for gorgeous naked-eye skywatching. At sunset the whole sky was striped with light from one horizon to the other.

Here’s another view, actually taken by me for a change. This is the unprocessed raw image, direct from my Coolpix 4500.

Moon halo photo by Kevin Zhao. Jupiter is inside the ring at 1:00, and the Pleiades are outside at about the same angle.

When the moon rose around 11:30, it was surrounded by a ring of faint light. I thought it was a moonbow, but that’s something different. The ring we saw around the moon is called a 22-degree halo and apparently has no other or more poetic name. That’s a shame. In the early morning, when the moon had gotten well above the horizon, it was surrounded by a complete circular halo with radiating clouds on either side. That was worth the clouds. I’ve been under wonderfully clear desert skies many times, but I’ve never seen a moon halo quite like that. For once, I think the clouds were worth it.

Update: There wasn’t just a moon halo, there was also a sun halo Saturday afternoon. Agnes Kwon captured it in pixels. Witness:

Many thanks to Agnes, Chad, and Kevin for letting me illustrate my post with their awesome photos!

Observing Report: SkyScanning in Oregon

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Observing report: An entirely different kind of virtual star party

If you’ve been following this blog or have trawled the recent archives then you know about virtual star parties on Google+, where astrophotographers put up real-time video images of celestial objects and a mixed group of professional and amateur astronomers and interested laypeople chat it up.

Tonight I got to experience a virtual star party of a completely different sort: a binocular tour of the night sky as projected on the dome of the Samuel Oschin Planetarium at Griffith Observatory. I was invited along by Steve Sittig, a good friend who works at the Webb Schools here in Claremont, where he teaches science, serves as chapel director, and runs the observatory. It is a curious lapse in my blogging that I haven’t covered any of the times that Steve and Andy Farke and I have passed an evening playing around observing with the big orange C14 in the observatory dome at the top of the Webb campus. We’ve chased comets and supernovae and had all kinds of fun–but those are stories for other posts.

Anyway, Steve hooked Andy and me up with tickets to this evening’s virtual star party, and a little before 7:30 we marched into the big dome, took our seats, and got our binoculars ready. I also got a few snaps, including this slightly-better-than-Bigfoot-level handheld portrait of the three of us not looking dorky at all.

I really didn’t know what to expect when the lights went down. I didn’t know whether the projector would project actual images of deep-sky objects, or just little groups of star-points that would mimic deep-sky objects, or maybe just the regular asterisms and constellation outlines.

All that uncertainty was dispelled as soon as the lights went down and the stars came out. The presenter directed us to Orion with his red laser pointer and went into some well-rehearsed patter about how it’s a big molecular cloud where new stars are being born. I was off and running. From the first view of the Orion Nebula (M42), it was clear that this was going to be a lot of fun. The nebula was big and detailed and looked pretty darned similar to its actual appearance through binoculars under dark skies.

I have to confess, I didn’t hang around for the whole Orion speech. I had stuff to see. I scanned south into Canis Major to look for the open cluster M41–and it was there, and looked legit. Followed the dog’s tail north and east to look for the closely paired clusters M46 and M47. There was only one glowing thing at their location, but there was something there and it was clearly supposed to be a star cluster, or maybe two close together. M35 in Gemini: there. Up to Auriga for M36/37/38: all there.

And so it went. The presenter did give us a pretty good tour of the northern sky, and he got to a lot of the stuff that I had raced ahead to find, but there was always more. I was shocked at the detail and fidelity of the images. Now, to be honest, not everything was there. A lot of the smaller or dimmer Messiers were not there–I looked in vain for M78 and M79. But I was often pleasantly surprised. M44, the Beehive, was an actual swarm of projected stars, not a hazy picture, just as it should have been. Better still, M67–hardly what one would call a showpiece object–was also there, just a bit to the south. And all of these things were not mere blobs of light, but were individually different and looked pretty much like they actually do through binoculars. It was pretty darned impressive.

I don’t know why I didn’t see this coming, since it was obviously technologically possible: the highlight of the evening was a tour of the Southern Hemisphere skies. We saw the Southern Cross and the Coalsack, the Jewel Box Cluster and the Eta Carina Nebula and the Southern Pleiades. I had seen these things before in binoculars, lying on the beach in Punta del Este, Uruguay, almost exactly two years ago. It was unexpectedly moving to get to visit them again, with binoculars, lying in much the same position in the reclined chair in the planetarium.

After that we came back to the northern skies for the summer highlight objects, which were very familiar since I just saw them last week. We hit the usual suspects: M4, M6, M7, M8, M20, M24, M25, M17. I popped up to the tail of Aquila and bagged M11 (actually in Scutum for any pedants in the audience, but it’s most easily found by following the eagle’s tail). All in all, by the end of the night the presenter had pointed out about two dozen deep-sky objects, and I had found another dozen or so that went unremarked. It’s weird to think that the projector is presumably putting up images of these faint fuzzies all the time, even though most of them are below the threshold of naked-eye visibility. I am going to start sneaking my binoculars into the planetarium on a regular basis.

When it was over, we all went out onto the observatory veranda to see what we could see in the real sky. Between the waxing gibbous moon, the regular LA light pollution, a bit of haze, and the modest aperture and magnification of our instruments, what we could see turned out to be “not very much”. We tried going right up to the fence and putting all the local lights behind us to try for the Andromeda galaxy and M13, but neither was in evidence. Oh well: the observatory staff did warn us that the real (Los Angeles) sky would be an unpleasant shock after the pristine projected sky. Steve said the projected sky was like what you see up in the Sierras, where the sky background is so black and there are so many  stars that it’s easy to lose your way; the bright stars that mark the constellations are simply lost in endless fields of distant suns.

The downside to virtual stargazing is just that: the endless fields of distant suns are not really endless. Using the binoculars allows you to see the projected stars and DSOs more clearly, but not the stars and DSOs between them. You can’t go very deep; there’s an inevitable limit and you hit it pretty fast. The Milky Way does not break up into a visually exhausting never-repeating parade of clusters, nebulae, asterisms, and rich fields of stars; it’s just a bunch of cloudy light projected overhead. You’re not really out there; the marvel is not at natural splendor but at human ingenuity, and you are, in the end, sitting in a big dark room using the world’s biggest sky app. Fun and interesting, for sure, but not nearly as rewarding as the real thing.

But I think that’s okay. Tonight’s exercise was an outreach, designed to get people who have never used their binoculars for anything other than spying on birds and neighbors to turn them skyward and see a few of these awesome things for themselves, and for real. Based on a wholly unscientific sample of personal eavesdropping, I think it was a success.

One final note. I had come across the idea of indoor stargazing before, in a blog post by Stephen Saber. He wrote,

darksky arenas…

I’m going to have some Superdome-sized Bortle-class 8 planetariums built with a projection accuracy to match. Really, really accurate. Open 24/7.
Peaceful outdoors sounds. Always a clear sky waiting. No more frozen fingers. No skeeters. Lunatic Happy Hours. Southern Sky Sundays and Messier Marathon Mondays.
Such an idea might offend a lot of hardcore Purists. Many might come just for the experience. But I really can’t see also faking the observation making any difference to goto users. *sorry. old habits.*
Or maybe night sky coliseums. Huge fields with perimeter walls rising to block local light pollution and outlying city lightdomes.

Would you come?
How far would you drive?
How much rain and cloudcover would it take?
Will preserving an area’s dark skies eventually come to this?

Having now done a light version of this, my answers are:

• Apparently I would.
• Um, 45 miles at least.
• None, just good company.
• I sure hope not.

So, virtual stargazing: weird, no substitute for the real thing, but still highly recommended. Go if you ever get a chance.

Observing report: Mt Baldy again, with friends

I did a short run up Mt Baldy last night, with some of my former students from the summer anatomy program. One of them, Kevin Zhao, brought along his Canon DSLR and got this awesome 30-second exposure. Kevin waved a little flashlight around during the exposure, which had the cool effect of making me look like I’m just beaming down here. This is looking east; if you click through to the big version, you can see that stars in the upper left corner, near the celestial pole, are little pinpoints, whereas those in the upper right corner, near the celestial equator, were already starting to trail.

And you can see some clouds. I thought these were going to be the end of the enterprise. We got up there about 8:45 and the sky was halfway clouded out. Over the next 20 minutes the clouds continued to congregate, until all that was left was a little sucker hole extending from the handle of the Big Dipper to Arcturus. So our first object was the double/multiple star Mizar and Alcor. I had along the XT10 and 15×70 binoculars, and people had fun cruising the skies with the big binos while waiting for their turn at the eyepiece.

Happily, by the time everyone had a look at Mizar and Alcor the sky had started to clear overhead, so we moved on to the Dumbbell Nebula (M27), the Ring Nebula (M57), the beautiful color-contrasted double star Albireo. By then the sky was almost completely clear, and it stayed that way, except for a stubborn bank of clouds to the south and west that kept us from seeing Mars and Saturn and almost denied us the moon.

By now we were rocking and rolling on summer sky highlights: the Great Globular Cluster in Hercules (M13), the Wild Duck Cluster (M11), a fine globular in Sagittarius (M22), the Lagoon Nebula (M8), the Swan Nebula (M17), and the M24 star cloud. We probably would have observed all of the clusters and nebulae that form the ‘steam’ rising from the teapot of Sagittarius, but the light pollution was worst in that direction so I stuck to a handful of the best and brightest objects. Sadly, the open clusters M6 and M7 were buried in the top of the southern cloud bank, so we missed them.

Speaking of that cloud bank, about 10:45 the crescent moon emerged from the flat bottom of the cloud deck and set over LA. Distance and haze dimmed its light somewhat and colored it orange, but we still got good looks at 50x and 86x. As the last person got a look at high mag, the horizon started to nibble away at the moon, and soon it had set.

After that we turned 180, to the northeast, and looked at the Double Cluster (NGC 869/884), the Andromeda galaxy (M31) and one of its satellite galaxies (M32). Then a couple of nice asterisms: Brocchi’s Coathanger, and the Engagement Ring around Polaris. Polaris itself was nicely split in the telescope (not surprising, a good 3-inch scope will split it, and it’s pretty easy prey for scopes of 4 inches and up).

Our final object of the night was the Cat’s Eye Nebula (NGC 6543), which was a bright round glow at 200x, and–as I had hoped–noticeably blue-green in the eyepiece.

By then it was 11:20 and we were all winding down, so we packed up and came down. It’s a fun drive, coming down the mountain–steep and twisty enough that you can really pour through the turns, but not so bad that you worry about burning out your brakes or sailing into a canyon. And the cool mountain air was most welcome after the 110-degree heat we’ve been sweating through for the past month.

Unfortunately with the moon waxing there won’t be much point in going out to dark skies for the next couple of weeks; last night was about the last night we could have gone and gotten skies dark enough to be rewarding. I’m glad it worked out.

Observing report: All-nighter on Mount Baldy

Whew! Last night rocked. Terry Nakazono was out from LA, and we had been planning for about two weeks to spend the night observing up on Mount Baldy. We had made a shorter, half-night run up the mountain back in June, Terry to chase faint galaxies with his SkyScanner and me to log a few Herschel 400 objects with the XT10. Last night was basically the same plan, but on steroids–the moon was rising later, and neither of us had anywhere to be today. My wife and son were both out of town, she on work and he on a sleepover, so I was released on my own recognizance.

We got up there about 8:45 and met fellow PVAA member Craig Matthews setting up his 8″ Dob. Former PVAA president Ron Hoekwater joined us a little later on.

Terry was rolling with his SkyScanner again, and aiming for galaxies in Ursa Major and Bootes. I decided to leave the XT10 at home and take the Apex 127 Mak instead. I’ve had that scope for about a year, but before last night I had not really tried it out under dark skies. It did go to the Salton Sea in February, but we were mostly clouded out that night. Five inches is a lot of aperture under dark skies, and I was anxious to see what the Mak could do. Mount Baldy is not stupid-dark like Afton Canyon or western Arizona, but it’s not bad at all. The Milky Way was prominent and showed a fair amount of detail, especially after midnight when a strong marine layer at lower altitudes effectively halved the light pollution to the south (Inland Empire) and southwest (Los Angeles). On light pollution maps Baldy shows as being in the Orange zone, Bortle Class 5, but between the altitude and the marine layer it is sometimes effectively Green (Bortle 4). Last night was such a night.

I also took along the Celestron Travel Scope 70, which I had otherwise only used for quick peeks from my driveway. I’ve been meaning to blog about that scope. Right now you can get the scope, finder, two eyepieces, a tripod, and a backpack carrying case from Amazon for about $70 shipped. The finder is a travesty–an all-plastic “5×20″ unit that is in fact stopped down to 10mm right behind the objective. I stripped the so-called optics out of mine and use it as a naked-eye sight tube, in which role it performs admirably, and a heck of a lot better than it ever did as a magnifying finder. The tripod is a joke, the sort of thing that gives other flimsy tripods a bad name. It struggles to hold a point-and-shoot digital camera steady, let alone a telescope, so I donated it to a museum. But the eyepieces are serviceable, the carry bag is fine, and the telescope itself is okay–more on this in the next post–so for $70 it is a screaming deal. As with the Apex 127, I was anxious to see what it could do under dark skies.

It was not yet fully dark when we arrived so I spent some time jawing with Craig. It was cloudless and clear where we were, but we could tell it was raining in the Mojave Desert, because the northeastern sky flickered with distant lightning. And we knew it was far off because we never heard even a hint of thunder. The lightning was not reflecting off clouds but off of the sky itself. It was as if the sky was on the fritz, like a bad florescent bulb. It was a profoundly weird and unearthly effect.

I started my observing run by putting the Apex 127 on Saturn. In addition to observing with “new” scopes, I was also rolling with genuinely new eyepieces. Explore Scientific has been having a CUH-RAY-ZEE sale on their well-reviewed 68, 82, and 100-degree eyepieces, so I sold some unused gear and bought a few: the 24mm ES68, which delivers the widest possible true field in a 1.25″ eyepiece, and the 14mm and 8.8mm ES82s. The Apex 127 is my longest focal length scope at 1540mm, so those eyepieces yielded 64x (24mm), 110x (14mm), and 175x (8.8mm). I also have a 6mm Orion Expanse that gives 257x–that is my default high-mag eyepiece in any scope. The ES eyepieces had just arrived in the mail last week so last night was my first time to try  them out.

Anyway, the seeing was limiting, with the view shaky at 175x and downright ugly at 257x, but Saturn was crisp and jewel-like at 110x and I could see four moons even at 64x. I haven’t checked the charts to see for sure which ones they were, but Titan certainly, and Dione, Rhea, and Tethys probably. I have seen up to five moons of Saturn at once before, but that requires steadier skies than we had last night.

After Saturn I hit a few favorite Messiers, including the globs M13, M5, and M4, all of which were impressively resolved for a 5″ scope. My favorite view of the evening through the Apex 127 was of the galaxies M81/M82 in the same field at 64x, with tantalizing hints of detail visible in both.

Then I got to work, finding and logging Herschel 400 objects. I was chasing mostly open clusters in Cygnus and Cassiopeia. I logged NGCs 6866, 7062, 7086, 7128, 7008 (a planetary nebula) and 7790. I also tried for open clusters NGC 7044 in Cygnus and 136 in Cassiopeia, but could not locate anything I felt comfortable calling a definitive open cluster at the charted locations amid the rich Milky Way starfields. This was also an issue with several of the Cygnus clusters I did log—at high magnification they tended to disappear into the surrounding star chains and asterisms.

Getting skunked is no fun, and by that time I’d been working on H400s for about two hours. For a change of pace, I switched over to the Travel Scope 70 and started plinking at Messiers. With a 32mm Plossl eyepiece I got 12.5x magnification and a stunning 4-degree true field–more like a finder on steroids than a telescope. I started with the Double Cluster as soon as I saw it was over the horizon, then hit M31, but didn’t immediately see its satellite galaxies. Then it was on to the “steam” rising from the teapot of Sagittarius: M8, M20, M22, M24, M25, M23, M18, M17, M16—these last three all nicely framed in the same field—M26, and M11 up in Scutum. Then back to the “bottom” of Scorpio and Sagittarius to catch M6 (M7 had already set behind a hill to the south—bummer), M69, M70, and M54, then all across the sky for M51, M101, M102, M13, M92, M15, back to Andromeda for a nice view of M31, M32, and M110 all prominent in the same field, M52, M103, M33, M76, and M34. I’d seen all these things before, but for most of them this was the lowest magnification I had seen them at, given that my binocular observations of them had mostly been with 15x70s. One of my favorite views of the night was M103 in Cassiopeia with NGCs 654, 663, and 659 in an arc below in the same field.

A little after 3:00 AM it was time for another goal: tracking down the outer giants. I had looked up the finder charts for Uranus and Neptune on Sky & Telescope’s website and logged their positions in my atlas. I found Neptune first, in Aquarius, using the Apex 127. Neptune was a very blue spark, and required 257x to appear non-stellar. Uranus, farther east in Pisces, was obviously non-stellar even at 64x. I also ran up to 257x on it, but the most pleasing view was at 175x. I had seen both planets before, but never as well, nor spent as much time on them as I did last night. Very strange to see giant Neptune as a tiny point of light in the mind-boggling darkness and immensity of space.

After observing planets I went back to the TS70 to continue the Messier survey. Logged M57, M56, M27, M45—absolutely stunning in the center of the field at low power—M72, M73, M2, M30, M75, M71—and old adversary from my early days with the XT6, but dead easy at low mag under dark skies—and M77. I tried for the faint face-on spiral galaxy M74 and suspected something there but couldn’t be sure. For a few these objects, including M72 and M77, I had to go up in magnification to pull them out of the skyglow or make sure they were not stars, using the 25mm (16x) and 17mm (23.5x) Plossls. I tried the 24mm ES68 but it was too heavy for the long cantilever from the mid-tube dovetail to the extended focuser tube of the TS70.

The last big show of the night was an upside-down kite shape rising in the east, with Jupiter at the top, Venus at the bottom, the thin crescent moon on the left, and Aldebaran on the right. I looked at the planets with the Apex 127 at 64x—the near-horizon seeing was bad but Venus’s crescent shape was well-defined, and Jupiter showed a couple of cloud bands and of course the four Galilean moons. Update: Pictures of this conjunction are posted here.

And that was it. The sky was rapidly getting brighter in the east, so we didn’t need artificial light to pack up. We pulled out at 5:25, went to Norm’s diner for breakfast, and I dropped Terry off at his hotel and went home for some badly-needed rack.

My final tally for the night was 8 new H400s, including NGCs 654 and 659; 44 Messiers, 42 of which I saw in the TS70; and 5 planets, including all four gas giants and Venus. Favorite observations were the flashing sky from over-the-horizon lightning, M81 and M82 in the same field in the Apex 127, M31 and both satellite galaxies in TS70, my best-yet views of Neptune and Uranus, and the dawn conjunction of planets, moon, and stars. Between dusk and dawn I observed five of the seven planets visible in a 5-inch scope, missing only Mars and Mercury (both were achievable, it turns out, I just didn’t try for them). It was a heck of a good night.

How did all the equipment perform? Stay tuned for the next post!

Observing report: the transit of Venus in Claremont

Here, just one day shy of being one month overdue, is my post on the transit of Venus on June 5. As promised, I took scopes downtown and did some sidewalk astronomy, and eventually some rooftop astronomy. As with the solar eclipse on May 20, the primary instrument was my son’s Astroscan with a homemade sun funnel, and once again it performed beautifully.

My partner in this enterprise was fellow Claremont paleontologist Matt Benoit. He was there for the whole thing, and helped keep scopes on target and help people understand what they were seeing. We hit a grocery store beforehand for soda and snacks and basically made an extended party out of the event.

I wanted to see the transit, period, but I was especially keen to watch the entry of Venus onto the solar disk to see if I could spot the “black drop effect” that bedeviled transit-timers in previous centuries. Sure enough, as Venus started to pull away from the limb of the sun there was a persistent dark blob or zone that seemed to connect the planet to the black space beyond, like surface tension keeping a drop of water from falling off the faucet. The black drop effect was once thought to be an effect of the atmosphere of Venus, but it’s not, because airless Mercury shows the same effect during its transits (the next of which is coming up in 2016, by the way). It’s nothing to do with our visual perception, either, since it’s easily recorded photographically, as you can see above. It’s now understood to be an effect of diffraction when a vanishingly thin line of light separates two darker spaces or silhouettes. You can see it by holding your finger and thumb up to the light and bringing them together–just before they touch, the black drop effect will seem to bridge them.

Along with the Astroscan and sun funnel, we had along the Celestron Travel Scope 70 with the aperture mask and solar filter described in this post, for direct viewing. Here’s my friend Marcy, who was there with friends for about half of the transit, getting her first look.

Although we both put in time on both scopes, for the most part I drove the Astroscan while Matt minded the Travel Scope. He also helped people get some photos through the eyepiece, as he did here with Marcy’s DSLR.

The view through the filtered scope was not as detailed as in the sun funnel, but the warm yellow color was more aesthetically pleasing, and many of our visitors appreciated both views.

Like the eclipse, the whole effect of the transit was a little unreal. In addition to the scopes, we also had eclipse glasses and a piece of welder’s glass. Every few minutes we would look up with our naked eyes and see a little black dot on the sun, and know that it was a whole world. And not just a world, but a twin of Earth. Someone on Mars watching a transit of Earth would see something very similar–our whole planet, all our evolutionary and human history, everything we’ve done or built (except for the handful of tiny things we’ve sent away)–all shrunk to a point, no larger, to the naked eye, than the period at the end of this sentence.

We had a steady stream of visitors downtown until a little after 6:00, when the theater blocked the view of the sun from the public square. So we decamped to the top of the parking garage across the street. Some people followed us over from downtown, and some found us up there on their own. One guy said that he found us because he had Googled for Venus transit events in Claremont and found my morning-of invitation post, which is nice, because that’s exactly why I put it up. In all, about 85 people saw at least some part of the transit through one of our scopes.

My son, London, watching the very tail end of the transit with the welder’s glass.

Venus was still crossing the face of the sun when they set together. As with the eclipse, I managed to get a shot right when the world crossing the sun touched Earth’s horizon. A moment later, it was gone, and the last transit of Venus until 2117 was over. I’m glad I got to see it, and to share it. I hope you had the opportunity to do the same.