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!

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...

The Cheapskate in me Comes Out!

Some of you saw my new telescope mounting a few weeks ago and found something definitely non-standard about it!  The photo at left shows it.  While I got a good deal on the mount, the owner kept his pier, counterweights and saddle plate for his new mount - I was on my own to replace them.   Fortunately, Dean Koenig of Starizona knew a machinist to make me 2 piers (!), one for my C-14, a tall version, and a shorter version for a Newtonian telescope.   I decided to go to Astro-Physics for the saddle plate.  But for the counterweights, I drew the line.  AP wanted big bucks for stainless steel weights - and really, they are just weights!  You could hang a toolbox off the end of the bar, as long as it balanced the tube assembly across the right ascension axis...  I tried to find a less-expensive alternative.  The weight by Roger's left hip is the result!

After looking at a couple options, I decided to take a Mirror Lab engineer's advice and get some regular steel water jet cut to rough shape, so that it took minimal machining to clean up.  And while the AP stainless weights were pricey, I copied their design by lining the hole with brass so it wouldn't scratch the stainless declination axis on which they mount.  There would also be a brass pin that is pushed by a screw to tighten it on the shaft - which also wouldn't scratch the shaft. 

While I don't consider myself a machinist, I can use most of the equipment in our little machine shop at work in a pinch.  There wasn't anything complicated about anything here, and it adds a little to the satisfaction I'll get when I use it.  The lathe is a little wimpy - it has a loose drive belt and won't take much of a load, slowing down the process some, but that is ok. 

Here are the steps I used.  First, I had some 6.125" circles water jet cut out of some 1" and 2" thick steel plate at A-1 Fabrication here in Tucson.  That step also included cutting a 1.875" hole in the center.  I figured that would come out to about 90 pounds of counterweight, which should balance about  120 pound load on the mount - well within its capacity, and more than all the telescopes I currently own.  The rough-cut disks are shown at left.  The first step is to grab it by the center hole and turn the outside diameter.  The machine marks cleaned up enough for me to stop at about 6.050" OD.

 

 

Next was to grab it by the OD and open up the OD to 2.00", which matched the OD of a piece of brass tubing I bought to line the ID.  Given that I'm new to machining steel, the surface roughness and accuracy of the lathe prevented a super-accurate fit, so after machining to a few thousandths of an inch, I cut the brass tube to the right length.

 

 

Since I couldn't do a true "pressed fit", I did the next best thing and glued the brass insert in place using J-B Weld to permanently hold it in place.  After an overnight cure, and machining the excess brass down to the steel dimensions, it was time to mount the locking screw and pin.  First step was to bore the right size hole.

 

 

The hole size is the correct hole for tapping a 3/8X16 threaded hole for the locking screw.  It helps to get the tap started using the drill press so it is perfectly aligned.  Then you loosen and back off the chuck and finish the job by hand.

 

 

Then it is time to trim down the brass rod I bought to the right diameter to fit the tap hole that i drilled in the weight.  Cut it to the correct length so it barely extends into the hole with the screw tightened down and you are done!  I can process a single weight in about 1.5 to 2 hours of after-hours activity, and am currently about half through my pile of weights.  Since these are regular steel that will rust, I'll likely sandblast them, prime and paint them before considering them finished.

 

So how much did I save?  Well, AP doesn't make 7 or 15 pound weights, but interpolating from the 5, 10 and 18 pound weight they do make, my weights would have run about $1150.  For this project, my water jet steel cost $550 for material and cutting, and my brass tubing and rod cost another $50 for a total of $600 - so about half price from the commercial version.  Of course, I should add something for my time, but as a hobbyist, it is hard to justify doing that, plus I had a little fun and some learning along the way.  Given what I've learned about how long it has taken for me to do the work, I'd think harder about repeating the experiment, but since I saved some money, I'm glad I did it!

Beaver Fever!

We're visiting the Midwest again for our "mid-holiday visit".  Compared to travel during Thanksgiving or Christmas, or even our standard, random times of the year, the period between the holidays is pretty slow and quite pleasant with empty seats on the plane.  So we're enjoying the Christmas lights around town and spending time with family for a few days.  For a little excitement and a gift for "Auntie Maj", we brought along our cat Annie, who spent her first few years living in our Illinois house.  Once we caught her (a real adventure!), the rest of the trip was uneventful, and she enjoys being the only cat in the household with unlimited attention from us, but rarely expresses much interest in the world outside the window or the birds and squirrels there.

I took a walk down along the river this afternoon and didn't expect to see much in the way of nature, and sure enough, lots of browns and greys, but without the accent of any white snow yet, although sister Kathy reports they got a dusting 3 hours to the west of us.  A friend we shared dinner with last night - an organic farmer, stated that after today we're setting a new record for consecutive days without snow at 280 days!  Perhaps a sign of global warming, since the record being broken is only 8 years old!

But something caught my eye - about 400 meters upriver, it looks like we've got a localized beaver infestation!  I've blogged before about seeing some signs of beaver, in fact, it was exactly 3 years ago.  But today there was a good-sized sapling about 6" diameter that was felled across the trail, and about 10 smaller saplings that had been cut and removed.  I didn't see where they had been moved to, a few trees that small wouldn't have had much effect on the Fox River, nearly 150 meters across at that location.  A Google search for "beavers in Kane county" only brought up pest-removal companies (no adult sites like Melinda's dirty mind concocted!), so they must be proliferating, which I'm all in favor of...  At left is a mini-panorama of the new clearing they are making, with a close-up at right with fresh shavings.  Below is a cross-eyed 3D view - cross your eyes slightly to fuse the stereo images...  Would be cool to see real-live beavers - will keep an eye out for our remaining days here!

Earliest Sunset!

Here we are on the 5th of December, a good 2 weeks till the Winter Solstice, and yet, if you look at a table of sunset times, right now is the time of earliest sunset!  "Wait", I can hear you all say - "I thought that happened on the first day of Winter on 21 December!"  Well, you would be partly right - the shortest DAY occurs on the first day of Winter in the northern hemisphere, when the sun follows its lowest arc across the sky.  Referring back to that table of sunset/sunrise times, you will also note that the date of latest sunrise occurs in mid-January, a couple weeks AFTER Winter Solstice.  So the shortest day happens on 21 December, but because the Earth's orbit is not completely circular, but slightly elliptical, the earliest sunset, latest sunrise and shortest day do not all fall on the first day of Winter.  If it did, life would be a little more boring, and we wouldn't be able to use these tidbits as excuses to learn something new.  But do go check out those sunrise/sunset times - you will see I'm right!  You can think of it this way - with the sunset time getting later day by day, it won't be long till the Winter that isn't here yet will give way to Spring and Summer!

 

Oh, and the picture above - taken a couple months ago from Kitt Peak National Observatory with my little Meade Telescope - an 80mm diameter apochromatic refractor, F/6, with a 480mm focal length and Canon XSi camera.

A Tall Tale Turns Out True!

My friend David Levine (shown here at left with wife Elinor at McDonald Observatory) was a buddy of mine from the local astronomy club, the Tucson Amateur Astronomy Association.  We shared similar interests, which included setting up for many public events, including the Grand Canyon Star Party, as well as more serious observing from TAAA dark-sky sites.  He had a way of telling a tale that was sometimes difficult to tell if it was true or not.  I could usually tell by the twinkle in his eye, but in the dark, it was harder to tell.  The Horsehead Nebula in your 8" telescope - Sure (wink-wink), I can believe that!  One of his stories involved observing a shadow transit on Jupiter, where the normally round shadow of the moon was crescent-shaped!  He was short on details, but indicated it was close to opposition when Jupiter was opposite the sun, rising at sunset, and the moon itself was blocking part of it's shadow.  Well, I had never heard of such a thing, and I've been around the block a few times, but he swore it was true!

Well Dave died a few years back but that tale has always stuck with me, and it just so happened that early yesterday Jupiter was at opposition.  Looking at a Javascript for the moon positions, it happened that Europa had a shadow transit about 6 or 7 hours past opposition - time for an adventure!  Since I work at Kitt Peak part time at their Nightly Observing Program, I was able to reserve the telescope for after the program.  There was a bright moon, so little demand for a late-night program.  Unfortunately, the shadow transit didn't start till after 2am local time - hard for a school night, but hey - these myths need to be dispelled!  I packed my webcam and laptop and headed to the Observatory after my wife left for her NICU shift.

It was a great, clear night and better-than-average seeing given the blustery breeze that was blowing.  I spent a couple hours trying some wide-field images in the moonlight, waiting for Europa to move into position.  Finally it was time to get set up - I've got little experience with the Imaging Source camera I got about a year ago, so it was a great night for some practice on the 20" scope.  The state-of-the-art of planetary imaging these days involves taking video sequences and taking the best images to stack into some truly amazing photos, and the camera/telescope combo worked well.  I took 2 minute sequences every 10 minutes or so and 3 of them are shown here.  At left Europa is shown approaching from the east and at right it is shown 20 minutes later as it casts it's shadow on the disk.

 

And some 70 minutes later, about the time I stopped with some thin cirrus moving in, the moon and shadow had crossed over halfway across Jupiter's disk.  The Great Red Spot had also rotated into view, and you can see a smaller red spot near the moon/shadow image.  Given the quality of the night, and that the seeing had deteriorated to about average, I'm amazed at how well these images came out.  And also, you can see that the disk of Europa indeed does occlude part of the black round shadow, a crescent shadow being the result - Dave was telling the truth!  A new observation for me, but I'm thinking that it has to be done within a few hours of opposition, and also, it will most likely occur for the inner moons Io and Europa.  I'm thinking the longer projection distance of the outer moons would make it more difficult to observe.  And yes, after disconnecting the camera and putting it away, I looked for seeing the partial shadow visually.  When waiting for moments of good seeing, yes, the crescent shadow could be seen, so it is possible to see with your own eyes.

 

Well, it was  long day at work after almost 3 hours of sleep, but it was a great adventure, and I'm glad to harken back to the old days sitting and talking astronomy with a dear departed friend.  The use of the 20" RCOS telescope is courtesy NOAO/AURA/NSF.

Something New, Different!

The Internet is a fun place, but it suffers from sort of a "sameness" when it comes to astronomy blogs.  I'm always searching for something that will draw me back time and again.  So it is always fun to find something new, my favorite this week is Astropixie, an astronomy and life interests blog from Australia.  She posts often and reading through the archives is a lot of fun - go check her out!  next time we update the "blogs we read" I'll be sure to get her up on those links.

One of the little links I found on an older post of hers was interesting - it brought to mind the link I found of Einstein at his blackboard where he would write whatever you wanted.  What, you don't remember that blog post?  Well, here it is in the original idea I had at the time - we put it on business cards once and passed them out whenever anyone wanted our e-mail or links to our blog when we set up at public events.  We've long run out of them, but would be fun to do it again - and yes, you can have "Uncle" Albert do your bidding by going to the website link on the image - and a variety of other images as well if you prefer...

 

Anyway, yes, the new link I saw - it is one where the message is written out by galaxy shapes!  The link, to My Galaxies, is written by Steven Bamford.  I believe he uses the Sloan Digital Sky Survey as source for galaxy images to use, and his routine allows you to try different images if the letters aren't clear enough for you, but it is kind of fun.  At left is one version of our blog address.  The website even identifies the galaxies used for the letters!  How often can you write someones name across the night sky - definitely something new and different!