Airglow, Not Aurora!

Last night's post evidently stimulated some interest, but some were perhaps mislead from my title of the post, "Arizona Aurora?".  At the time I observed it, the northern location of the brightest sections, and the pinkish color seen in some images had me thinking it might have been aurora.  In addition, there were auroral displays seen as far south as Northern Utah on Saturday night, 16 June, the night AFTER my first observation.

So what I saw and the photos posted are airglow - the brightest airglow displays I've ever seen!.  While resembling the greenish color of aurora, and occupying nearly the same part of our atmosphere at about 90km altitude, they are different phenomenon.  Aurora are caused by energetic particles spiraling down the earth's magnetic field, while airglow is caused by excitation of atoms in the upper atmosphere by daytime solar UV radiation.

There is an excellent site on atmospheric optics called "Optics Picture of the Day".  They maintain a gallery on a wide range of optical effects, including the above topics, with very well-written explanations of what the images illustrate.  My favorite image of airglow from the site is from an all-sky image at local midnight from Nebraska a half-dozen years ago.  There are also examples of similar banded airglow to my image and an image from space showing airglow from above.  They also have several examples and explanations of gravity waves.  I highly recommend bookmarking the site and returning frequently to learn about many of the sights we can see in the sky, both day and night.

Arizona Aurora?

We are just back from a spectacular 5 day break from reality in Northern Arizona, mostly at the Grand Canyon for the annual star party there.  We've many previous posts regarding some of our time there on previous trips, so check here for a link to some of those exploits. 

On our way there last Friday (15 June), we stopped at the Bed and Breakfast of buddy Tom Taylor, proprietor of A Shooting Star Inn.  We'll write a separate post about our evening there, but what I'd like to cover tonight is a display of sky lights.  What looked like a thin layer of clouds moving in showed structure I've seen before from dark sky locations - airglow with gravity wave structures.  The main clue was the green color from oxygen emission. Shown here is a frame of several taken with a 16mm fisheye with a 1 minute duration, with only minor levels adjustments.  The bowl of the big dipper is coming into the upper left, Cassiopeia at lower right and Polaris, the North Star is upper right center.  It was a cool display, and like I said, the casual observers there thought they were thin clouds,  but the exposures show the green emission.

Then again just last night (19 June), on our last night of observing, showed a very similar glow and structure.  Again, the observers thought clouds were moving in, but again the exposures showed the telltale green emission.  I thought hard about it being aurora, but didn't see any characteristic rays, even though the display was very strongly centered due north.  Peaking right at about midnight as we were putting telescopes away from the night's public observing, after dropping Melinda and another observer off at the campground, I went back out to Yavapai Point and shot more frames from rim side for about a half hour.  I thought I could detect some pinkish or red color in some of the frames, but the structure and motion is consistent with airglow and gravity waves. 

I collected the 30 or so frames into a time-lapse and uploaded them into YouTube so you can see the structure and motion of the glow.  Interestingly, the structure was moving north on both nights, and the wind, which was very strong while taking the frames, was also towards the north.  In case the YouTube viewer doesn't load, go to this link to view on their website. Anyway, really cool stuff, but not aurora, which is pretty rare, even in Northern Arizona.  More posts about the events of the last week to come!

Don't Know What Came Over Me!

Generally, other than friends and family, I have little reason or excuse to take people pictures.  So I don't know why I suddenly got the urge on our trip to Columbia, South Carolina to image strangers.  And not only strangers, but strangers taking pictures of others...  Seems weird, but I encountered the scene at left on our walk along a river path on the Congaree River.  I loved the combination of friend-with-a-camera on a walk and photo-op with Mom and Baby Boy.  Of course, Mom is trying to elicit a response from a distance, and Baby Boy, not too sure of things, sends a glance Mom's way...

So that is the picture that started it.  And once started, I couldn't stop!  It seemed suddenly that everyone was taking pictures of others, and as a trained observer, I got some sort of vicarious thrill by documenting it.  A few minutes later there were a couple friends down in the middle of the river taking pictures on a cell phone.   I particularly like their reflections and the fast shutter freezing the running water.  So once started, I figured I should set ground rules for running this photo theme.  My initial rule was that subject and photographer both have to be in the picture, and my picture should  be taken at the same time as the imaged photographer shoots.

Of course, rules are meant to be broken, in this case, right away as a few minutes later, this picture presented itself sans photographer.  Now don't forget we are in the South, which in my mind brings up cotillion balls and debutantes, or the assemblage could be the prom queen and her court.  In this case the photographer, or more likely, the assembled parents of the group were snapping away and I shot back at them after we passed.  I like the oblique grouping of this scene and the imagined stories of a world that I've NEVER been a part of...

The next day we went to the Riverbanks Botanical Gardens and Zoo and had a great time.  And again, more picture-takin' going on.  At left a pair of twins (they gotta be twins - who else dresses exactly alike?) documenting their day next to the flamingos, and at right, Mom takes a picture of some friends. 

So will this weird motivation continue?  It hasn't struck since the return from SC, but we rarely get into crowds like this.  Hmmm - Grand Canyon next week, RAGBRAI next month - we'll see if the mood strikes again!

The Telescope Maker's Art

I'm way behind on posting.  This one is from way back in April from our trip to Columbia, South Carolina.  Besides the primary reason to go to visit my mother-in-law Betty, another was that I had heard from her that they had a display of antique telescopes from the collection of local amateur astronomer and collector Bob Ariail.  We actually posted about Bob, and the early stages of that optics collection a few years back, when we last travelled there with friend Roger Ceragioli.  Shown here at left are 2 placards of introduction to the display.

The South Carolina State Museum is an amazing place.  It is located in a 120 year old textile mill, the first mill to be fully electrically powered at the time.  It is a huge space, 4 floors of displays and artifacts of art, history, science and technology.  There are visiting and always changing exhibits - they were about a week away from opening a "Titanic" artifact exhibition, and when we were there last time there was a major Napoleon display.  The Bob Ariail exhibit is the first part of a major expansion of the museum for a planetarium and observatory, which will feature an Alvin Clark 12 3/8" refractor as it's centerpiece - also donated by Bob, I believe. 

Besides the on-site display, there is also a digital version that can be accessed on line for those of you who cannot travel there in person.  The exhibit was spacious and displayed a good variety of telescopes from the last two and a half centuries.  Interestingly, the collection includes a 12.5" reflecting telescope that Bob himself made 35 years ago and used for making over 10,000 estimates of variable star brightnesses for the AAVSO.  While Bob's own telescope was made by his own hand of plywood, the antique telescopes from the 1700s into the 1900s were made by true artists in the materials of the day - fine brass, chrome and wood.  It was amazing to see the craftsmanship of these devices - my only regret is that we were not able to look through them.  Perhaps in the expansion project they will figure out a way to allow such intimate contact with these historical artifacts.

I'm a big fan of giant binoculars, owning a not-so-antique pair of 20X120 Japanese battleship binoculars now approaching 70 years old.  I was amazed to find not one, but two pair of Zeiss instruments from a couple decades earlier.  I was also amazed to see an illustration of one of these at the Grand Canyon at Kolb Brother's Studio, where they still sit objectives pointing down dejectedly, eyepieces missing.  I didn't have a clue they were Zeiss, but the illustration seems to support it (seen in the background in the image at left). The pair seemed a natural for a stereo pair also, so have included it at right.  These are a "cross-eyed" viewing pair - click to enlarge, then cross your eyes slightly to view the right image with your right eye and vice-versa.  There will be a center image that will display the stereo effect.

Shown here also are some of the earliest achromatic telescopes - two-lens objectives of differing glasses that correct chromatic aberrations of singlet lenses.  At left the image shows a Dollond telescope from 1780.  From about the same time period at right is a Gregorian reflecting telescope from 1760.  The reflecting telescopes didn't have the color error of the early refractors, but were difficult to make well because of speculum mirrors and small diameters available at the time.

As someone associated with optics and astronomy the display was doubly interesting to me, but the wide variety of the instruments even kept Betty and Melinda interested while I hung around taking picture after picture...  But as I mentioned earlier, the craftsmanship really stood out - the engraving and attention to detail was amazing.  If we could only look at a distant horizon scene and watch the troops of Sherman approach...  Oops - that is a different section of the State Museum!

An Excuse to go to Kitt Peak

A Harvard grad student discovered my blog and queried if it would be possible to get a tour of Kitt Peak.  It is not like I need an excuse to go - normally I'll go at the drop of a hat to pick up a shift on the Nightly Observing Program (NOP), or cover a VIP daytime tour, or just go up to observe on my own along the road to the peak.  I envisioned this one being some combination of the first two, so with permission of the director's office in hand, our new friend joined me and wife Melinda (who had never taken part in an NOP) for an afternoon and evening tour of the mountaintop observatory.

It was a spectacular day!  Temps peaked in the upper 80s, and the smoke and haze that hampered observing a week earlier had mostly cleared out, revealing crystal blue skies and strong sun.  We arrived shortly after noon, and after conversing at length with some of the Visitor Center (VC) staff, we took a walking tour of the 2.1 meter telescope.  With our 3pm deadline to clear the domes (so night time observers can prep their instruments), we drove to the 4 meter for the top-down tour of the biggest instrument at Kitt Peak.  The picture at left shows the view from the 4-meter viewing gallery towards the south showing part of the menagerie of telescopes and the striking mountain Baboquivari about 15 miles to the south.

Getting back to the VC as the day staff was leaving, the NOP crew were on duty.  I reminded them we would be joining them for the early part of their show, and got a daytime glimpse of the orange star Arcturus as they opened the domes for the night's observing.  Time on our hands, we headed off to the dining hall for an early dinner.  Now I hardly ever complain about the food served here or anywhere, but this particular night we enjoyed prime rib!  Melinda was quite impressed and I'll likely get future ribbing about that perk of the NOP position...  Absolutely stuffed, we took an amble down to the McMath-Pierce Solar Telescope, including a visit to the observing room.  There we found that the telescope was going to be used that night and the observers showed us around, including a view of the sun with the West Auxiliary scope.  The observers, from the University of Wisconsin, are looking at the sodium atmosphere of the moon, and since it was moving towards last quarter, this was their last night.  They invited us to stay to watch the closeup sunset projected on the screen, but we opted instead to join the NOP crew for the naked-eye view.  In our time observing the sun there, a lady bug was captured in what must have seemed a long walk across the sun's disk...  I just realize a day later that watching him crawl across the sun wasn't too different from many of the time-lapse movies of the recent Venus transit, except this time Venus sports lil' legs, antennae and black-on-red spots!

On our way back to the VC, we happened to notice a bush absolutely filled with everything from ants to ladybugs to a variety of bees and what appear to be pepsis wasps, otherwise known as tarantula hawks.  So called because they are the only known predators to tarantulas other than humans, they paralyse them and lay a single egg which will hatch and feed on the still-living arachnid!  But they also feed on pollen and nectar, and that is obviously what they were doing here on the flower stalk of a beargrass plant  While there were many beargrass clumps with flower stalks, for some reason, this one seemed to be the popular one.  While scary-big, perhaps a 6cm long body, they seemed pre-occupied with their feeding and paid us little mind.  I read that the females have curly antennae, so this one appears to be male...

We finally pressed on to the VC and found the "sunset tour" about to start.  We joined the crowd of about 30 visitors on the short walk to the sunset view, learning about various telescopes along the way.  Lead guide Blythe is shown in the picture at left, with glasses and pointing against the sunset glow.    As the sun sank, the domes around the mountain came to life and opened allowing the interiors to cool in the rapidly dropping temperatures.  Shown at right is the WIYN .9 meter telescope and its observer enjoying the sunset.  The guides Blythe and Jim talked about a variety of topics - told people about the possible Green Flash at sunset, but it was a little too hazy to be obvious.   They did point out the Belt of Venus - the sunset line and the earth's shadow rising into the eastern sky.

Finally, Jim pointed out that the previous evening they spotted Mercury, the elusive innermost planet.  After losing Venus in the evening sky about 2 weeks ago, we've again got a planet in the evening at least for a month or so.  He was expecting it to be quite low, and thought it might have gone into the haze layer without our seeing it.  So the NOP group departed, headed back to the VC for a classroom session on planispheres and binocular use.  We stayed at the sunset point for a little and eventually spotted Mercury - it was a LOT higher than we were led to believe and was quite easily visible.  Shown in the picture here is Mercury in the twilight sky against the background of the SARA 0.9 meter telescope flamingo - you might have to click on it to spot the planet to the left of its head.   SARA, a consortium of schools mostly located in the Southeast, use the flamingo as a mascot...  So yes, in the next few weeks go out and check out Mercury!

On our way back down to the VC we availed ourselves of the 20" telescope and grabbed a few views of Saturn (spectacular in the excellent seeing), the globular cluster Messier 13, and galaxy Messier 104.  We were on our way down the mountain by 9pm - a long but most excellent day at the Observatory!

Early Cicada Season!

I was out looking at the cacti in front of the house the other day and a bit of movement caught my eye.  A closer look revealed a Cicada - the first week of June!  I've not heard any, but then, my hearing loss and tinnitus from work have me hearing cicada-like buzzing all year long!  Normally you hear them during monsoon season, but I don't recall ever seeing them this early.  I grabbed the macro lens and grabbed a few frames, none of them particularly good as he was down about a foot off the ground - hard for this old fellow (me) to reach very easily with a monopod.  Adequate for a snapshot, though. This was taken with the Canon XSi, 100mm macro and on-camera flash.  I think this one is Cacama valvata, the white stripes were what initially caught my eye.  I'm sure we'll see many more the next couple months through the monsoons, but the first of the season is always spectacular!

Venus Transit w/a Few Friends!

Yesterday (Tuesday the 5th), was the big Venus transit.  Of course, there was one just 8 years ago, but visible only in Asia and Europe - not visible in the US except for along the eastern seaboard for about an hour at sunrise.  The next one isn't until 2117, yep - that's right, 105.5 years!  So, I'm thinking I might not make it to the next one, so needed to get organized and take a look at this one.  The big question was should I go off somewhere on my own to take pictures, or share the view with friends?  Anyone who knows me should know that answer - go where you can find the biggest crowds and share the view! 

Transits of the inner planets are rare things.  They also play historical and important roles in science.  Transits of Venus were particularly important in defining the scale of the solar system.  In the 18th century, we knew the distance to the planets, not in miles, but in units of the distance from Earth to the Sun.  Only by using parallax methods, observing a Venus transit from widely spaced points on our planet and noting the subtle differences, could we triangulate the distance to Venus in miles, and thus the absolute scale of the solar system.  There is a rip-roaring tale of adventure that Captain James Cook took to Tahiti for the 1769 transit at this NASA site.  The voyage took nearly 3 years, and 40% of the crew died - deemed acceptable losses for such a voyage in those days.  I highly recommend reading the account - certainly worthy of a modern documentary or movie treatment!

I did want to try to image it, as well as set up some scopes for the public.  The imaging setup consisted of my workhorse G-11 mount with a 7" apochromatic refractor built by Roger Ceragioli about 10 years ago. It is an excellent little telescope, and a perfect focal length for imaging fields smaller than the sun's diameter.  Unfortunately, the public nearly always demands that anything set up before them needs to be looked through.  It took nearly constant attention to keep folks from hanging off the photographic setup, even though there was clearly a camera clicking away every 20 seconds...    In one attention lapse, someone who had watched me adjust the scope looking through the little guide scope, did the same and while I patiently checked after him, the sun was completely out of the field!  Should have set up traffic cones and barbed wire!  I did have 3 other devices set up for them - my "big" 20X120 Japanese battleship binoculars, a little Meade 80mm apo refractor, and a "Sunspotter II" folded telescope that safely projects an image of the sun onto a screen.  The image at left shows workmate Kirk and Janet mugging for the camera over the Sunspotter II projector.

With all that gear to set up, including a borrowed canopy to provide just a little relief from the unrelenting Arizona sun (projected high of 100F), I was the first to arrive at 12:30 for the 1500 transit start.  Securing a mall parking pass, I got to work.  Unfortunately they had chosen that morning to apply steer manure fertilizer to the mall, and early on the flies were bothersome - but hey, I'm a farmboy, so toughed through it!  I started setting up the tracking mount, then the first camerawoman came by, wanting to see part of the setup, so after she set up her tripod and I cued her to start, I carried out the big binoculars and plopped them on the mount - nearly a third her diminutive stature, she was impressed!  I put on the solar filters, but it was nearly high noon with sun overhead, it was uncomfortable to look so high in the sky...  I alternated with other scope setup, then the canopy.  Other amateur astronomers arrived, then the public, then, as if sniffing out a story, the press came for the live early news coverage.  Besides the early encounter with the channel 4 correspondent, I was live on channel 9,getting to talk a bit about the binoculars, and I also had an NPR crew interviewing me for an upcoming radio program.  Image at left is of "second contact", when the full disk of Venus first fully enters the disk of the sun.  Roger's scope was used at 1/4000 second for most of the transit images.

Of course, by that time the transit was well under way.  I had finished my setup with minutes to spare, and Melinda had come down early to help setup and run a telescope.  With 2 other volunteers assisting, I got to focus on getting the camera system going and not deal with the public early on.  Right on schedule (funny how that happens!), the startlingly big disk of Venus inched into the sun's disk.  One of the things I was looking to record was the atmosphere of Venus refracting a ring of light before it fully came into the sun.  I never saw it, but took a couple frames with slightly longer exposures to try to capture the "aureole" of Venus.  Hours later, once loaded into the computer, by stretching the contrast beyond the limits of common sense, it appears to be barely visible - cool!

During the bulk of the transit we had some huge crowds - I was guessing over a thousand, but I heard some estimates of 3,000!  Of course, setting up in "astronomy central", within a block of Steward Observatory, Lunar and Planetary Labs, National Optical Astronomy Observatories, Optical Sciences and the Mirror Lab, it seems I knew or recognised a good percentage of the people who came by.  The big binoculars were VERY popular, sporting some of the longest lines.  It's 20 power 3 degree field is almost the perfect complement to viewing something the size of the sun or moon.  Believe it or not, I also got a very strong 3-D effect of Venus floating in front of the sun - impossible, of course, because of the great distances involved, but strong nonetheless!  Note the picture here of mom helping her son view - daughter is preparing, getting her fingers nice and sticky with candy before she gets to reach for the eyepieces!  I saw and caught her in time to prevent a sticky mess, though I was busy a good part of the afternoon on mascara patrol, keeping the eye lenses clear of that contaminant!

There were a lot of telescopes there, 40 by some counts, and it wasn't till the crowd started to wane that I got to walk around and say hi to anyone.  One of the more unusual setups  was by Tucson Amateur Astronomy Association (TAAA) member Debra, who had set up her "light bucket" telescope.  For those who don't trust solar filters (and there were quite a number who don't), Debra fastens an actual bucket to the back of her Schmidt Cassegrain telescope, and projects the sun onto what looks like a translucent screen made of shower curtain!  The image was sharp, large and bright, and was a great way to safely view the transit, as shown here. 

The Sunspotter II that I had setup attracted some attention too.  I originally saw the first models at Texas Star Party or Riverside Telescope Makers Conference a couple decades ago, and ordered mine.  They are numbered and dated, mine being made in June of 1991, so is well over a couple decades old.  Mine uses a simple singlet long-focus lens, the beam of which is folded around the interior of the triangular solid before being diverted downwards through an eyepiece where the sun's image is projected onto a screen.  There was also a current version of the Sunspotter, first mounted on a tabletop (where it is designed to be used), but I didn't get to it until it had been placed on the ground.  The current model is much improved - my older version (visible in the top picture with Kirk and Janet above) has no mount at all, but in this case I attached it to a tracking mount.  The new version has a very smooth looking alt-azimuth tabletop mount that looks exceedingly easy to use and point.  It also sports a larger diameter achromatic lens and improved eyepiece that gives a larger sharper image than my model II.  However, most Internet prices have them at $400, while I recall the price I paid in 1991 being $50 or $60.  The price of progress and a better product...

Once the transit was well underway, time seemed to fly by.  I had lots of people come back and repeat looks through the binoculars, telling me they were the best view there.  Finally the sun dropped below the Modern Languages building, which I've got a couple frames of!  Once the sun was gone, the people left and we packed up, and rushed off to our next appointment - a tour of the Mirror Lab for the NPR crew, and eventually dinner with friends at The Crossroads Mexican restaurant in South Tucson.  It took about 2 pitchers of water and a couple beers to hydrate everyone, and we were stuffed by the time we headed home at 2130 to a house of hungry cats (4 hours past their normal feeding time!).  But the transit was a spectacular event, and the celebration on the UA mall was a great success.  The last image shown here is very near mid-transit, though after looking at all these pictures that I and others have taken, they start to all look the same!  I think we inspired some kids as well as parents, and seeing that always invigorates me, convinced that doing public astronomy is just about the best use of telescopes - inspiring others.