Monday, January 21, 2013

Another Celestial Near-Miss!

My post from last week was about the image of the setting sun just missing Kitt Peak from the Babad Do'ag pullout on the Mount Lemmon Highway.  Tonight Melinda and I were about to head out to dinner and I got a call from buddy Pat, talking about getting his new telescope out and observing the Moon right next to Jupiter.  While chatting I walked outside and looked up - holy crap, they were really close!  So I talked my way off the phone and quickly set up the lil' Meade 80mm F/6 APO to take a tripod shot.  The enclosed is a combination of  3 shots from 1/400 to 1/25 second to attempt to get Jupiter's moons without blowing out details on the Moon.  Partly successful, clicking the full-size image, you might be able to spot Ganymede below and Io just above Jupiter.  At least you can see how really close they were together in the sky - in fact, from much of South America, the moon occulted, or covers the disk of Jupiter!  It hardly seems fair that they've had 2 occultations of Jupiter in the last month, while we don't get one for another 13 years!  The good news is that I delayed our departure to dinner by only about 15 minutes to get the shot, then waited till afterwards to post to the blog - first things first!

Thursday, January 17, 2013

Oooh - A Close Miss!

As I mentioned in my last post, there was to be a sunset alignment with Kitt Peak National Observatory from "Bad Dog" Overlook (actually Babad Do'ag - Frog Mountain in the native tongue).  So I was joined by 2 of my local Tucson readers to observe it.  It was a spectacular afternoon, very clear sky, though a brisk breeze out of the east was going to play havoc with shaking long focal length telescopes...  At left is the view shooting almost directly up-sun with the zoom lens set to about 70mm, distant mountains Baboquivari on the left, and the flat-topped Kitt Peak on the right side of the view.  The Catalina Highway, used to access the mountain, is the diagonal road across the bottom of the frame.  At right, a mesquite tree and yucca line a ridge about  a half mile or mile away to the north.

After getting set up for imaging, I visited some with Jim and Dick who also came up to observe the sunset.  Each of them brought gear - Jim an H-alpha telescope, Dick a little refractor with white-light solar filter.  As soon as the sun touched the horizon, I knew it was a little too far to the north.  It never touched the solar telescopes that make up the left side of the Observatory profile.  Oh well, these things happen!  Looking at these images, calculations indicate that the sun should be about 6 arcminutes further south, or a declination of about -20.895 degrees.  Like I warned in the previous post, unfortunately, the sun moves about 12 arcminutes/day this time of year, so you've got to be lucky for a perfect alignment this far from Solstice!  By the way, you can look closely and see some nice sunspot groups on the suns face.  While atmospheric refraction gives the upper edge a greenish/blue rim and the lower edge red (another recent post!) interestingly the sunspots have the lower edges green and the upper edges red!  When you pause and think about it, the explanation is pretty simple - the lower edge of a sunspot is actually the upper edge of the bright edge of the sunspot, so has a green upper edge like the top of the disk. 

The thin haze or smog shown in the up-sun picture above had a surprise waiting for us after sunset.  Once the sun disappeared below the horizon, it made a perfect screen to see shadows cast from the domes and mountains!  I don't think I've ever seen an effect this strongly before.  With the contrast stretched just a little, you can see each mountaintop structure very clearly casting a shadow.   These are officially called crepuscular rays, and are often seen by casual observers, mostly around sunrise and sunset.  They tend to fade fast, but even after a few minutes, they were still visible after switching to the hand-held zoom lens for a wider exposure.  One is even faintly seen from a peak far to the left side of the picture.  It was really cool to see.

Ok, I'm officially done with these Kitt Peak sunsets for the season - I promise not to submit any more till the end of the year - I promise!

Sunday, January 13, 2013

(Yawn) Another Sunset Trip...

After today's cheap movie matinee (Les Misérables ), we exited to continued cold temps, but blue sky, so we decided to take a little sunset trip to Babad Do'ag Overlook (shortened to "Bad Dog" to those familiar with it!) near milepost 3 on the Mount Lemmon Highway.  I've been sort-of looking to figure out the date that the sun sets behind Kitt Peak from this alternate location, which broadens the Solstice-only observations from 6 miles further up the mountain road.  A check a week ago indicated it would be this week, so we went for another data point tonight.

With the lower elevation and later sunset, we didn't leave till an hour before sunset, but we still had plenty of time to set up the William Optics APO I posted about 10 days ago.  And sure enough, more pictures with which to take some measurements, shown at left.  While it missed the Observatory, it did catch the solar scopes on part of it's trip to the horizon.  Apparent also are some really nice sunspot groups, even though viewing right over the horizon is not optimum.  Sure enough, the alignment is this week, Wednesday the 16th if my calculations are correct and anyone is interested...  Unfortunately, the problem with this later alignment is that the sun moves a considerable amount from day to day, so only this one chance!  By my calculation, the needed solar declination is -20.788 degrees, Wednesdays is -20.796.  Not sure if I can get away on Wednesday, we'll see.

There were some other great items to image.  Across the valley is a nice antenna array that makes a nice, high-contrast object upon which to focus.  I believe several FM stations broadcast from this peak in the Tucson Mountains, shown at left.  At right is a view of the cubical-shaped Multiple Mirror Observatory about 45 miles south our observing spot atop Mount Hopkins.

A little after sunset the Moon that was such a sliver yesterday was quite visible.  And since it washigher in the sky than yesterday, the "earthshine" became visible after it got a little darker.  This "old Moon in the new moon's arms" is actually from the earth!  The phase of the Earth, as seen from the Moon is complementary - in other words, if the moon is new, near the sun, the Earth would be fully illuminated and extremely bright, resulting in the "dark side" of the Moon being visible.  At left, a short exposure shows craters down to the maximum resolution of the camera and telescope (shown at nearly full camera resolution).  At right, with an exposure of nearly a second, the crescent is purposefully overexposed to show details revealed by the earthshine.  Since I wasn't tracking, the Earth's rotation blurred the moon slightly, but not enough to degrade the shot too much.

And of course, high in the eastern sky was Jupiter.  An exposure of just .1 second overexposed the disk of the giant planet, but revealed the 4 Galilean moons.  From lower left are outermost Callisto, Europa, innermost Io, and on the right side of the disk is Ganymede.  This shot is displayed at full camera resolution, and while the 770mm focal length of the telescope doesn't show a lot of detail in this tripod shot, it is fun to see what you can get with the snapshots we're showing here...

Saturday, January 12, 2013

Young Moon!

It is always a little breathtaking to spot a young moon a day or two past new.  Such was the case tonight - it was new moon about lunchtime yesterday, so tonight the 29-hour-old moon was easily spotted in the twilight.  And while the palm trees are supposed to make you jealous of our normally warm winter weather, Tucson is suffering a cold snap!  It was just a couple degrees above freezing when these picture were taken, and it is supposed to be near 20F for a low - cold for us!  The local news is filled with stories to protect your plants and keep pipes from freezing, normally not a worry when the temps only drop a couple degrees  below freezing...  By the way, in taking these photos, to keep moon and trees in focus, I used exposures up to 3 seconds at F/16 for the depth-of-field to keep both close to focus...

While there are no bright evening stars in the western sky, the Moon is not alone!  The planet Mars is still hanging out low in the west and is still spotted if you look for it.  Shown here above the palm at left, it still has a tint of orange to it,  but is about as far as it can get from us way across the solar system, over 210 million miles away.  It will drop further into the solar glare into invisibility in a few more weeks...  But in the meantime, enjoy the clear skies the cold weather brings and keep those eyeballs skywards!

Friday, January 4, 2013

It's A Major Award!

The call came about a week before Christmas... "You remember the Telescope Expo last month," the voice asked? "Well you won one of the door prizes!" The call was from Lunt Solar Systems who was supplying the prize, one of the premier makers of specialty narrow-band solar filters. I had visions of a new solar-viewing telescope, and I barely heard the woman explain that my prize was, in fact, a 70mm diameter telescope suitable for someone beginning in astronomy. And while I would have loved to have one of these babies 45 years ago (in fact, I saved my money for something very similar back then), I'm a little past a scope like this.  But I picked it up today at lunch, and talked my way into a killer tour of the facility where they actually polish the etalon filter surfaces and telescope optics in house.  I actually got to look over the shoulder of  company owner Andrew Lunt as he sun-tested a newly-built telescope-filter system.  It was way-cool!

But I did take the chance to check the product out...  The door prize looks to be pretty well made, a Vixen Telescope, achromatic lens, with a couple decent looking eyepieces giving 35X and 70X.  At least it wasn't like the department store telescope  from long ago that bragged 254X!  So I needed to find a youngster that would be able to put this to good use.  While I have a couple great-nieces and a nephew about the right ages, I have dreams of actually making some small scopes some day for them, and it would be so much cooler to have a scope made by Uncle Dean than a commercial one supplied by him...  So we brought it to the TAAA meeting tonight - a great talk by former Palomar Observatory outreach coordinator Scott Kardel talking about the history of that great telescope.  After the meeting I announced I had a new telescope for someone about 12 or 13.  Irene Kitzman raised her hand saying she had 11 and 13-year-old grandsons, so she will forward it along to them.  I feel much better knowing that it will be put to good use by some kids.  Thanks to Vixen and Lunt Solar Systems!

Update:  Irene provides the following recent picture of new scope owners Jack and Matthew with Grandpa.  They look the perfect age and should have fun with the scope!

Wednesday, January 2, 2013

Fun With Telescopes!

Like many amateur astronomers, I've got more than a couple telescopes.  Most are better at some tasks than others.  Some get used a lot, others seem to get passed by.  This post is about a 4.5" (11cm) apochromatic (APO) refractor that for various reasons, isn't used very often.  More often I grab the smaller 80mm F/6 APO that has taken multitudes of pics for this blog...  Shown at right, the 11cm William Optics version has a great focuser, but the longer focal length makes it very sensitive to vibration - likely one cause of my issues with it...  I did use it the other day for the picture of the sun - at right is the "Green Flash" picture taken with the 11cm with 1.4X extender to make it about 1080mm focal length.
That same night, I took a profile shot of Kitt Peak National Observatory from that spot near Milepost 8.5 of the Catalina Highway, then we stopped down near Milepost 3 for another shot.  Taken from the 2 locations about 3 miles across, it is a substantial-enough baseline that I thought they might show some 3-D effect from the nearly 60 mile distant Observatory, even though all the scopes are about the same distance.  Now realize that the two pictures shown here are taken nearly 30 minutes apart, accounting for some of the brightness and color differences...  But I put them together, and sure enough, the stereo effect is quite apparent for the "south ridge" domes and solar telescope at right, as well as the separation of the central ridge of the mountain.  This is a cross-eyed view, as always, cross your eyes slightly to look at the right picture with left eye and left picture with right eye.  The central image will show depth.  Click the image for the full-size view.
The a day earlier I had taken this same telescope up to "A" Mountain to the west side of downtown Tucson, to try a time-lapse sequence of the cranes working on a stadium addition on Campus.  While nearly 3 miles away, the resolution was quite good, though I had to go to some effort to avoid vibration.  I enabled mirror lockup on the camera and also used a 2 second timer to allow vibrations to damp out before the image was taken.  The full frame is shown at left - the telescope again used with the 1.4X extender to lengthen the focal length to 1080mm.  While not extra-ordinary, don't forget these images are compressed a lot for the blog, so I made a full-resolution crop of a frame section at right.  From the nearly 3 miles, the resolution appears to be about 2 inches or so.  Again, this is the same frame, but not reduced in resolution when you click to look at the full frame.  The resolution is quite good, considering that the white building behind the crane is Catalina High School, another 2.5 miles behind, with lots of heat waves seen in the longer distance.
When used without the extender, only the central part of the image is sharp to my fussy eye.  It may be worth my while to invest in a corrector made especially for this telescope to recover the full field.  But with the extender, and pending corrector, it is a scope worthy of more use!