Monday, December 31, 2012

Year End Review!

I'm taking a page from our friend Andrew Cooper and writing a year end review of my favorite photos and events from the last year!  It seems somehow appropriate that our 100 post of the year be on New Year's Eve, and review the highlights of 2012.  For details, go to our blog post from that date.  So here we go!
Jan 3: Night flash pic of Whitewater Cranes looks has x-ray appearance.

Jan 13 : Public program on Kitt Peak w/Zodiacl light, Moon and Venus


Jan 29 : 4 panel panorama ofTucson lights and Kitt Peak


Feb 5: Stereo Pair of Moon and Oak (cross-eyed view).


Feb 26 : Post public observing session w/20" on Kitt Peak.

Mar 13: Stereo view cactus flower Organ Pipe Monument (cross-eyed view).


Apr 21: Gambel's Quail proclaiming territory!

May 6: Blackhawk Helicopter transiting Supermoon!

May 13: Milky Way rises over TAAA Star-B-Que on Kitt Peak

May 13: 30m telephoto shot of Antares region at Star-B-Que.\

May 21: Melinda caught F-18 on sun before Grand Canyon Solar Eclipse.

June 9: Blythe (glasses, pointing) leads sunset talk at Kitt Peak.

Aug 13: Me on RAGBRAI, enjoying pork chop on a stick!

Aug 15: Automated sequence captures Hannah and Sphinx moth!

Aug 17: Great niece Alivia's 6th birthday!

Sep 8:  Dave Harvey's Passing - my absolute favorite of his Venus Transit.

Sep 14: Violet and green banded airglow display from Shooting Star Inn, Flagstaff.


Sep 17: Russians!  The View from "A" Mountain.

Sep 19: Group shot at Kitt Peak McMath-Pierce Solar Telescope.

Sep 20: More Russians - Maya enjoys her Kinnect game.

Sep 22: Russians in western wear at Tucson Mall.

Sep 24: Russians at Meteor Crater.

Sep 25: Russians Chillin' at Canyon.


Oct 15: Illinois fall colors.

Oct 30: Hawaii w/in laws and Pele!


Nov 1: West coast of Big Island by Moonlight looking SSW.

Nov 9: The Girls at the lava flow at base of Mauna Kea.

Nov 1: Andrew Cooper allows a peek at Keck spare mirror segments.

Nov 14: More Hawaii - Gold dust day gecko in native environment.

Dec 4: Europa's crescent shadow crosses Jupiter at opposition.

Dec 29: Lucy, aka Lucifur, aka Lulu in closeup.

Sunday, December 30, 2012

Green Flash Musings

I've been enjoying the University shutdown between the Christmas and New Year's holidays.  Melinda has been unable to work after her recovery from oral surgery has been slower than expected, and her continued use of pain meds.  So we used the chance to continue chasing the sunset from the Mount Lemmon Highway from a different location than normal this last Friday, 28 December.  While we missed an exact Observatory alignment (though collecting another data point for future use!), we were able to enjoy an excellent, clear sunset, with a touch of a "Green Flash" at the upper edge of the sun.  What causes this green upper edge?  Well, let's talk about it!

I've noted some of this atmospheric effect several times on this blog.  For instance nearly 3 years ago I imaged Mercury very low in the sky and it showed the characteristic colored spectrum in its image, shown here at left.  And about 2 years ago, I imaged the bright star Archernar, which only gets a couple degrees above the horizon from Tucson shown at the right.  Both of these, taken with the Celestron 14" with 4,000mm effective focal length as well as the sun image above with a small telescope of about 1,000mm focal length, show the characteristic blue-green fringe atop the image, with the reddish part below.
There is a simple explanation for this - in all cases we're looking very near the horizon through long paths of the Earth's atmosphere.  Because the earth is spherical in shape, as is its air surrounding it, long pathlengths show the prismatic effect of the curved atmosphere.  One of the world's authorities on atmospheric optics, Les Crowley, who runs the Optics Picture of the Day site, has numerous examples and discussions about the Green Flash, including links to commentary, more examples, simulations and a reading list by Andrew T. Young deferring to him as the ultimate authority.
I had e-mailed Les, taking exception to some of his remarks regarding the requirement that mirage must be present for the Green Flash to be seen.  His response, as well as excellent examples of his discussions follow.  Be sure to click on the links to see those examples!  My initial comments to him preceded by a >:
Hi Dean,

> In my recent readings to catch up, I read your comment that "A green
> flash needs a mirage, ordinary atmospheric dispersion is too weak to separate colours
> sufficiently." I'm not sure I totally agree.

I was being deliberately provocative because many explanations cite normal
atmospheric dispersion or 'prisms' as the cause and therefore mislead rather
badly. I've campaigned for some time that flashes are rather more than that
and I think that the tide is turning. But we still get vague and misleading
statements like this:

But not as bad as this howler on corona formation:

The green rim ( is another matter.

> As an astronomer-type, I've
> spent many years observing atmospheric dispersion, and while landlocked in
> Southern Arizona, where the green flash is rare (perhaps proving your point),
> atmospheric dispersion is rampant. Note the following blog post of mine:
> <>
> Which noted the strong prismatic effects of the atmosphere at low elevations.

I had intended to compute the angular dispersion for a normal atrmosphere at
zero sun elevation. However, Rayleigh (Proc. R. Soc. Lond. A 1930 126,
311-318) did the calculation a long time ago and that should suffice. He
gets, for a refraction at the horizon of 35', a dispersion between H-alpha
and H-beta (red-green) of 22 seconds of arc. That is less than the eye's
resolving power. Rayleigh argues via some experiments involving masks and
slits that the dispersion is sufficient for a green flash at an horizon.
However, he talks only of inferior mirage type flashes
( and not mock-mirage flashes where
the green is at the top of the sun's disk and above the horizon
( Rayleigh's experiments used
comparatively short path lengths and might therefore represent flash visibilty
under ideal conditions rarely experienced outdoors. In terms of duration,
the red to green a mask occultation would take 1.5s upwards depending on
latitude and solar declination and that is about right (but not supportive of
Rayleigh) for an I-Mir flash duration.

There are some example of Rayleigh mask type flashes
( but even here, more extreme
refraction (not mirage) effects are likely. I agree with you that some
extreme but non miraging refraction could give inferior-mirage like
flashes but consider that most flashes at or near the horizon are mirage amplified.

Notwithstanding Rayleigh, modern flash understanding is that extreme
refraction normally leading to miraging better accounts for observations. I guess you
are familiar with Andy Young's extensive site and modelling on this
( Distortion and
multi-imaging of the sun prior to the flash(s) and apparently choppy horizons
are visible indications of mirage conditions.

> We rarely get the thermal layering in the desert you say is needed for the
> green flash, but we do occasionally see it as the last second of sunlight
> disappears behind distant mountains, that I suggest is caused by pure
> atmospheric dispersion.

Agreed - also the layering over hills can be accentuated by the airflow.

The layers over flat terrain can be quite thin and this one
( in the Libyan Desert
comes to mind.

> Mostly I observe from Kitt Peak National Observatory, home of a 1.6
> meter solar  telescope that produces an 80cm diameter of the sun. On occasion I've been
> able to watch the sunset with that instrument and have, in fact, seen
> the "blue  flash" as the upper clearly blue-violet edge of the dispersed sun slips below
> the horizon (certainly not visible to the unaided eye, though).

On that solar image scale I would think that normal refraction would be
sufficient to show a green or blue rim which would normally be
unnoticed by the unaided eye. If at the last minute it appears to spread horizontally along
the horizon then some abnormal refraction is present.

>Anyway, very much enjoy your postings, perhaps I can contribute someday

I hope so, and thanks for provoking me in return on green flashes!

Best wishes,

Les Cowley
Atmospheric Optics -
Optics Picture of the Day -
I think the gist of his discussions is that the Green Flashes we are seeing from our mountaintop and desert locations are not the traditional Green Flash, but rather masked Rayleigh dispersion.  The inferior mirage effect that occurs over water (but not over desert terrain), amplifies the Rayleigh dispersion effect for seaside observers.  I'd be glad to hear of opinions of others!

Saturday, December 29, 2012

A Couple Beautiful Blondes!

With the year winding down, I was looking for blog topics and they were right in front of me - kitties!  And it seems appropriate because we've had Lucy now for exactly a year!  She came to us as a kitten from our vet.  Seems she wasn't getting along with her adult cats, so asked us if we would take her.  At left is a picture of her then - sitting forlornly in her dog crate as everyone got used to having her around.  We blogged about her then, and likely a time or two since.

She has always been a bit of a problem child - litterbox issues (6" away is close enough for her!), and while she wants to play with the other cats, they often don't take to her jumping on them kindly!  But she has the most beautiful eyes - sort of a copper glow with a hint of greenish central part.  And her head tilt, from what we suspect is a little brain damage, makes her so cute you can't stay mad at her long.  And with all the food here she has puffed out enormously!  She isn't a little kitten any more!  I happened to get these current photos of her from the top of the sofa as something outside caught her eye.  She was distracted enough that I could zoom in for some closeups of her beautiful eyes...
A few minutes later Lucy ran off, and was replaced by YellowCat.  He is a former feral, who has been living in the house now 2.5 years.  He lived out in front of the house for some time eating the food we supply there.  He always has such a worried look on his face - look at the old photo of him at left - always with the frown.  You still see it occasionally, but he is a real glutton for attention and more often than not he'll join you on the couch to watch TV with you.  We wrote a classic blog post back then about introducing an FIV+ feline (kitty Aids, which YellowCat has) into the household.  It seems a week doesn't pass when someone finds that post from a google search, often leaving comments. 
I couldn't decide which of the two head shots I liked best, so include both.  He is the nicest cat - will start head-butting you if you are not paying enough attention to him, or if he wants more after you've stopped.  And he has the prettiest grey-green eyes...  And after his successful integration into our household (read the link above) he is just the friendliest cat (though still looks worried sometimes) and seems to get along with everybody.  What more could you ask?!

Tuesday, December 25, 2012

A Christmas Eve Cloudfest!

As I've noted in the past, one of the new holiday traditions we've followed the last couple years is to drive an hour north of our house in Tucson to photograph or observe the sunset alignment behind Kitt Peak National Observatory.  It happens a few days before, and a few days after the Winter Solstice, so, of course, prime dates are Christmas and Christmas Eve.  Fortunately, most everyone is available to join us as they don't work on those days - but I understand about family obligations.  But there are a few astronomy buddies who have grown children who are joining us in our tradition.  We were joined by at least 10 people along the road on the Mount Lemmon Highway at milepost 8.8 for the annual alignment last evening.

This year we were joined by our TAAA buddy George Barber, who moved to Utah 2 years ago for a job.  We were pleasantly surprised when he turned up in town for the Holiday, so he joined us.  That is him in the right photo, standing next to Richard in the truck, with Elaine and Carrie at far right.  In the left photo, Bill was aligning his scope at left, with Mary sitting behind it, then Susan is visible, with the Jims at right...
And while we were concerned a few days earlier with threats of an arriving front, it cleared early morning and we enjoyed some spectacular blue skies all afternoon and for the trip up the mountain.  Just as we arrived at the observing spot, there were a few tiny clouds over the distant view of the observatory, and as we set up gear, waiting for the sunset, those tiny clouds grew into larger ones, obviously borne by pretty high winds - you could actually see them whipping past in the telescopic view of the mountain.  And as the photos show, the sunset alignment was wiped out by clouds at the last moment - I only got to briefly see the silhouetted solar telescope in the picture at right.
But as the saying goes - "when life throws you lemons, make lemonade", it was quite a pretty sunset!  Obviously after the sun set behind our view of the Observatory, it spent some time in the clear again, and you can see a faint shadow of the 4-meter telescope at the right side of the mountain casting it's shadow up into the sky.  Somehow, Melinda caught it more clearly in a hand-held shot with her telephoto and camera at right - you can see the shadow being projected into the cloud itself!  Click for the full-sized image and to see it a little more clearly.  But even though we missed the observatory silhouette, we had a good time, and proceeded down to Village Inn for some socializing over dinner as we often do after an astronomy club meeting.  It was fun spending time with friends, consoling each other over our miss, but telling yarns, tall tales, and big plans for the future.  And of course, there is always next year...

Tuesday, December 18, 2012

Birthday Sunset Alignment!

After working some long hours, I've finally got a chance to post about my most excellent birthday on Sunday!  With the approaching Solstice and yet another Kitt Peak sunset alignment, I put out an e-mail alert to the Tucson Amateur Astronomy Association (TAAA) to see if there was interest.  Now the 16th is a little early for the alignment - normally we do it a couple days later, but since most work on weekdays, the trigger was pulled and we had about 8 people in 4 cars join us.  We had 5 virgins who had never seen it before, and I brought the big 20X120 binoculars with solar filters for a great view, while shooting video with Melinda's camera with an older Celestron 5" telescope. 
Sure enough, the sun moved over the silhouette of the National Observatory, a few clouds had little effect on the spectacular view...  But interestingly, the earlier date's view was readily apparent - the sun was just a bit further north than it usually is, so it covered all the scopes on the mountain for only a second or two, as opposed to the normal 5 or 6.  Note at left that the center of the sun is well above the mountain profile - compare it to the shot at right taken a couple years ago when the alignment was nearly perfect with lots of room on both ends of the mountain!
A few couldn't make it on Sunday, so another trip is planned for Monday, 24 December.  Yes, it is Christmas eve, but it seems to be becoming a Christmas tradition for a number of us.  I've heard rumors that there might be some weather coming in, but fingers crossed it will be a fun time of socializing and observing without staying up late!
Oh, and on my birthday Sunday, we were joined by our Phoenix buddies Bernie Sanden and Donna Tippens.  After the sunset we went out to a local steak place and had a great dinner.  All of our birthdays should be so much fun - thanks guys!

Saturday, December 15, 2012

Slightly Drab, but not Flat!

We're safely back in Arizona again, but our last day in Illinois, I took a walk down along the Fox River adjacent and into Tekakwitha Forest Preserve, where I stop almost daily in Spring and Summer.  With the arrival of Winter in a few days, there was little to grab my attention, yet with the absence of vegetation, it opened up some other views.  More about that in a minute...

The streak of snowless days continues at 286 as of today, but last week there was a smattering of, well something...  In the shadow of some of the tree roots collected little piles of what looked like snow pellets.  But since there wasn't a measurable accumulation (.1"), it didn't count...  But at least it was a little hint of what will eventually swallow up the landscape soon...

Down on the river, it was a little blustery once out of the shelter of Tekakwitha Woods.  And quite the cooling effect producing a significant drop in the wind chill.  It made for some ripples in the water, darkening the appearance of the water without the sky reflecting off it.  In the distance you can see ducks bobbing in the water - tougher to spot in the waves...  Looking down from the walking/bike bridge you can see the 2 different waves - the roughly parallel ones caused by shallow water running over underwater features, and the high-frequency little ones on top caused by the wind.
I got a fan e-mail the other day from a reader who enjoyed the 3D stereo views.  I nearly always take image pairs for stereo, and the lack of leaves opened up some views that you normally don't see in the summer.  Across the river, you could see a shelter over in the Jon Duerr Forest Preserve.  A standard image of it is shown at left.  Since it is some distance away, it appears flat - not many clues to give a sense of perspective.  But as I've tried to imply in my previous posts on 3D imaging, by taking a second identical exposure with a horizontal shift, and view one picture with each eye - presto, chango - a real 3D picture with true sense of depth!  At right is the pair of images, and as I've also implied in previous posts on the topic, I present them in a cross-eyed view.  Cross your eyes slightly so that you view the left picture with your right eye and right picture with your left.  The result will be a 3D image in the center with depth.  In this case, because of the distance to the scene, I moved about 5-6 feet horizontally between images, so it is known as a "hyper-stereoscopic" image, since the separation is more than your natural eye separation.  The cross-eyed viewing method works for the thumbnail image here with the text, or it works with the full sized image if you click on it.  Because the method works for any image size, it is what I use in the blog.
While the image pair works well, even looking at the full-sized image is limited in the resolution of the scene.  In this case I cropped down the image to nearly the raw-pixel resolution of the frames to enable you to see more detail.  In the image pair at left you get a better view of the 3D image, and the effect of what the baseline of the image separation gets you in defining the depth in the view.  you can plainly see the wall of trees at the shoreline separated from the more distant park shelter behind.
A few minutes later I was walking down along the river and saw another of my "favorite trees".  I've posted about these before - numerous in the woods here, a hackberry tree (Celtis occidentalis).  The bark is quite amazing, not only for the ridges built up on the surface, but the micro-layers on the ridges.  I'm thinking that the micro-ridges are actually growth rings manifested in the outer grooves - but then, what do I know?!  A closeup similar to above is shown at right...
Ambling a couple hundred yards towards the west, the trail turns uphill and approaches the visitor center, which appears to be shut down for the season, without open hours posted.  Along the way, frost appeared on the trail, and across the valley, the golden glow of the low sun was being cast in the jumble of downed leaves.  The 3D view pulls you into the scene, even the frosty glint of the leaves on the trail gives you a bit of chill...
Finally, with the sun still up, I hated to waste some sunshine, so after driving home, took the short walk up to where I saw signs of the beaver a few days back.  Looking for an appropriate stereo view, I shot nearly down-sun showing one of the girdled large trees and another good-sized one that was downed over the trail along the river...
The stereo views shown here are easy to produce.  I am pretty careful to be sure to translate smoothly and keep the camera in the same orientation.  Occasionally I have to manipulate one of the images to better match them by rotating one of them slightly, or change the image size if I wasn't careful to translate square to where I was pointing (ie, the camera was slightly closer to the object in one of the frames...).  I use an early version of Photoshop Elements (2.0 - that I got with my first DSLR at least 8 years ago).  Loading the two frames, I use the Photomerge command to set them up next to each other, which allows me to do slight shifts to align, or even overlay them to see if they can be fixed by rotating or changing image scale on one of them.  Try it if you feel inspired, but hopefully you enjoy them and don't have any issues fusing them into 3D images...