Saturday, October 29, 2011

Western Conjunction

In the western sky, inferior planets Venus and Mercury are putting on a show the next couple weeks (inferior in the sense they orbit inside the Earth's orbit).  With a clear western horizon, brilliant Venus can be spotted about 10 minutes after sunset.  With the growing darkness, Mercury can be spotted nearby.  They will be very close the next week or so, but by the 14th, Mercury reaches it's greatest elongation from the sun and shortly after dives towards the horizon.  Unfortunately the Autumn ecliptic makes a shallow angle with the horizon and they don't stray far from the horizon or into a dark sky, but Mercury should easily be spotted with binoculars near Venus.  I've been watching it the last few evenings, but I've yet to see it with the unaided eye, though it is easy in binocs.

The picture above was taken this evening as I was headed towards Tucson from an afternoon of work at the Kitt Peak National Observatory.  This picture was taken about 30 minutes after sunset from Ajo Road and Sandario with a 200mm lens.  At the bottom center of the frame are the silhouettes of the telescope domes on the Mountain - the 4-meter on the right to the Solar Telescopes on the left.  If you get a clear sky the next few days, get out and take a look!

Thursday, October 20, 2011

Fall Colors!

Tucson and the Sonoran Desert are often accused of not having seasons.  I beg to differ, but to the careful observer, there are actually 5 or more we go through, not the standard 4 most of the country sees, considering our Summer monsoons that most do not see.

Fall colors, though, are mostly lacking.  Deciduous trees and plants in the desert drop their leaves when cold weather comes, or when enough time passes since the last rain it is no longer profitable for the plants to keep them.  In the highest mountains in Southern Arizona, as well as the higher terrain in the White Mountains and Flagstaff area, stands of aspen trees do turn a brilliant yellow-gold and draw bus loads of tourists.  But the Tucson area is mostly denied any reminders of Fall, save the moderating temperatures.

However, lately I have noticed a subtle coloring in recent trips through the desert to Kitt Peak and even driving through local neighborhoods.  Ocotillo plants, which normally only display leaves for a couple weeks after a rain before dropping them, are displaying brilliant to pale yellows in this short transition into cooler weather.  I pointed this out to a co-worker on our drive to Kitt Peak last week and he noted that in 30 years in Tucson he had never noticed them.  Particularly while surrounded by the still green palo verde and mesquite trees, the ocotillo make a spectacular, if singular impression.

Ocotillos are interesting plants.  Mostly they appear as nearly dead-looking sticks with rows of thorns along their length.  Immediately after a decent rain leaves sprout and in the Spring, brilliant red flower clusters cap the ends.  But while they carry thorns, they are actually hardened leaf stalks - they are not cacti.  And for a couple weeks, they remind Midwestern transplants a little of the colors they are missing back home...

Friday, October 14, 2011

Kitt Peak Open House and a Visit to the Third-Born!

Last weekend the astronomy club was invited to help out with Tohono O'odham Night at Kitt Peak National Observatory.  Many hundreds were expected, and all the telescopes were open to residents of the reservation, where the Observatory is located, as well as  "Friends" of the Observatory.   We were invited to set up our personal telescopes and help out with the crowds up near the 36" telescope on the south ridge near the WIYN Telescope. 

It was quite the event!  Melinda and I arrived early to set up before the 4pm start time.  We stayed up by our telescope, but there were lots of activities going on below by the visitor center - you could hear a "chicken scratch" band, and there were local vendors of fry bread and crafts, traditional dancing, that sort of thing.  I figured it was their party, and we stayed and did our duty...  And there were LOTS of people!  They ran a shuttle up from the picnic area where they directed folks to park, they even ran buses from the reservation high school for those who didn't want to drive the mountain road.  Folks loved the view of the moon, even in the late afternoon as sunset and dusk settled.  Our location was one of the most scenic on the mountain, with spectacular views of the other domes and surrounding desert.  The only problem - it was also COLD!  I'm not sure how cold it was, but with the steady breeze, it was quite bone chilling when standing for hours.  Joining us with their telescopes was John Kalas, Bill Lofquist, Jim O'Connor and a few others.  Spouses mostly hung out in the 36" warm room.  Even our brownies didn't ward away the chill!

Another draw for me was the 3.5 meter diameter WIYN telescope (WIYN stands for Wisconsin, Indiana, Yale and NOAO, the major partners), built in the early 90s, was the 3rd large telescope that I had a hand in polishing at the Mirror Lab.  And with the telescope open, and sporting a large eyepiece for the occasion, provided a chance to finally look through a telescope that I've polished!  I was at the dedication in October of 1994, hoping to take a look at Saturn, but a storm had come through and we could barely venture outside that night, let alone think of observing with a new shiny telescope.  Normally there is NEVER an eyepiece on the scope - digital detectors are so much more efficient that there is rarely a chance to look through the scope with your eyes. 

We paid a visit before sunset, inspecting the telescope and chatting with Dr. Patricia Knezek, director of the WIYN Observatory.  While sporting a large 3.5 meter mirror, it is a very short telescope and squat mount, so the dome is small and comfortable.  With the telescope pointed halfway up the sky the primary and tertiary mirror can be inspected quite easily.  Having polished it, I was eager to get a look at the reflecting surface.  It had seen better days!  It was pretty dirty - almost looking like it had gotten sprinkled on, which happens more often that you think with quickly-changing mountain weather.  And while cleaned regularly, typically with a carbon dioxide snow technique (think CO2 fire extinguisher!),  it is recoated every couple years.  We were told that because of heavy demand for the coating chamber in the basement of the 4-meter building across the mountain, it had been 3 years since recoating.  It is scheduled for the next shutdown.

The view through the dome slit and open "garage doors" to help with dome seeing, was quite spectacular.  To the east, you could see the great alignment of telescope domes - from the WIYN, directly east is a small dome where currently a 16" Meade is located for the Nightly Observing Program.  A short walk up the hill is the 36" where we were set up - my van can be spotted in the photo.  Past the 36" is the 2.1 meter telescope, built nearly 50 years ago, and past that is the heliostat of the largest solar telescope in the world - the McMath-Pierce Telescope, about the same age. 

We did our telescope duty - lots of passers-by, families with kids in tow, ignoring the cold (or perhaps thankful for the change from desert heat).  They loved my high-power views of lunar craters, and Jupiter a little later as it rose.  By 8:15 our counter showed 135 people had looked through the scope!  With telescopes scheduled to close at 8:30, now was our opportunity to go look through the WIYN!

We made the short walk over and surprise - there was a line.  We were told there were about 100 in front of us!  We heard rumors some had spent an hour in line, but we persevered...  We talked to the director some more, and found out that even though I polished the mirror, that plus $1.49 will get me a cup-o-coffee at Circle K.  No cutting the line for us!  The thing I kicked myself for later was that I hadn't brought camera and tripod - with the bright moon and it's ambient light it would have been fun taking pics of the line of folks leading up to the stepladder and eyepiece.  Next time!  Finally the time drew near - they were looking at the Ring Nebula, M57 in Lyra.  It is a great object for such a large telescope - it has a high surface brightness and is small, both a benefit because even the lowest magnifications with such a large telescope is typically 600X or more.  And yes, even with the squat telescope pictured above, you do need an 8 foot stepladder to reach the eyepiece at the Naysmith focus.  We had heard rumors that color could be seen in the Ring's oval, but I suspect it was overactive imaginations.  The central star was easily visible and it was quite an impressive view - stars were very small for such a high magnification, though it appeared it wasn't quite finely focused.  With over 85 people behind me, my few seconds of observing time quickly drew to a close, and we ambled out.  It would be great to do it again - a moonless night would be great, and of course, an hour to look at a couple objects would be "heavenly"!

As we returned, everyone was putting scopes away, so we did the same.  I had set up cameras that were still churning away taking some sequences in our absence.  The camera pointed north showed the spectacular view of other telescope domes illuminated by moonlight, and the interior of the 4-meter lit up with their low-dome lights.  The Big Dipper can be seen just above the horizon and the lights of Casa Grande and the glow of Phoenix.  Faintly below the dipper the radio towers of South Mountain can be seen, an even 100 miles away.  The other image is in the direction of Tucson with a telephoto lens - easily seen are the headlights of Ajo Way, route 86, which is the main route between the Observatory and town.  The dark silhouette of the mountain is Cat Mountain, passed as you leave town.  Below that are the lights and illuminated runway of Ryan Airfield.

It was a great evening, even with the cold, and with the early conclusion, we were home by 11:30 or so - early for us.  We'll be volunteering again in a few years when they have another!

Tuesday, October 11, 2011

Seeing the Light - Astonishing Mira

I was perusing the Sky and Telescope website the other week, and ran across an observing report prompting sky watchers to go out and observe the variable star Mira, now at maximum brightness in the eastern sky in early evening. 

Mention of the star transported me back a decade or more back in time to a night I was out observing with my buddy Roger at the TAAA's observing site at Empire Ranch.  I know it was 12 years ago because Jupiter was very near it's present position, which takes 12 years to circle our sky!  I had just finished an 8" diameter objective prism, and had it mounted on my 11" Newtonian for some visual spectroscopy - breaking the light of stars into a rainbow.  Because the prism deviates the light a considerable amount, I was sweeping the sky, looking for the bright spectrum of Jupiter when I accidentally swept up a remarkable spectrum!  Instead of most stars which showed the rainbow colors with only a few dark narrow absorption lines, this one, also pretty bright, was crossed by much wider absorption bands and also had emission lines in the spectrum!  It was very distinctive and astonishing.

With a little study to locate what we had found on the star charts, it was Mira, also then near maximum light.  Mira is a long period red variable, and since it was discovered hundreds of years ago and is the first of it's kind, is called a Mira-type variable.  Over a period of 330 days it varies from 2nd to 10th magnitude - from easy naked eye visibility to invisibility even with binoculars (a factor of about 1600!).  Interestingly, in the past 12 years since swept up in my spectrograph, it has gone through 13 cycles, so reappears now at maximum brightness...

This last January, I posted about objective prism spectroscopy, and showed some spectra of the Hyades star cluster.  Using a similar setup last weekend (used a longer focal length lens for more color dispersion), I again imaged the spectrum of the bright blue star Vega to compare it to the Mira spectrum.  The result is shown here with a spectrum of the star Fomalhaut for comparison.  Fomalhaut is about twice the mass of the sun and as a result burns about 3,000K degrees hotter (about 9,000K vs about 6,000K for the sun).  With the hotter temperature, the spectrum of Fomalhaut is dominated by hydrogen absorption lines.  Mira, at a much cooler 3,000K, has a much more complicated spectrum, the cooler temperatures allow heavier elements and even molecules in it's atmosphere, dominated by the molecular bands of Titanium Oxide.  Also noteworthy are Hydrogen Beta and Gamma lines are in emission rather than absorption.  It makes for a very striking spectrum visually.

Mira should be easily visible for a few more weeks in the eastern sky to the south (right) of Jupiter.  The picture here was taken on the first of this month with brilliant Jupiter and Mira over the lights of Sierra Vista and Fort Huachuca.  If you are interested in checking out a variable star, hunt it down and watch it disappear over the next couple months.

Sunday, October 9, 2011

A New Gadget

We have recently (today) received a comment that we should have a translation tool on our blog site, for our "Worldwide Audience"!  It never even occurred to us, but what a great idea (thanks, Ian!)!  While Blogspot doesn't seem to have a gadget that does exactly that (without subjecting you to advertising, which we do not support), it might work if we include a link to Google's translation assistant.  I've used their page frequently and it's probably not too bad.  Give it a try and leave us some feedback!  The link is at the top of the list in the right hand column.  To use it, copy and paste the text you are wanting to translate, and then choose the languages.

Wednesday, October 5, 2011

Aden Meinel, "The Great Man" passes at age 88

The hits started coming in a couple days ago and still continue today at about one per hour - Google directing folks looking for "Aden Meinel" to our little blog.  If you do the same search, we're the third Google entry after the National Optical Astronomy Observatories and the Wikipedia entry.  Turns out that I posted about Aden Meinel's visit to Tucson about 18 months ago, as part of Kitt Peak National Observatory's 50th anniversary.  Lots of hits can only mean one or two things, but in this case, we learned yesterday he died on Sunday at his home in Henderson, Nevada.

His meager entry in Wikipedia reveals little of his giant stature in Tucson.  He was director of Yerkes and McDonald Observatory when he was put in charge of the search for, and served as founding director of the national observatory which was chosen to be atop Kitt Peak, about 50 miles SW of Tucson.  After the dedication of that institution, he went on to be the third director of Steward Observatory, and from there went on to establish and serve as director of the Optical Sciences Center (now bearing his name) at the University of Arizona.  And that is to say nothing of the plethora of research papers he and wife Marjorie published in optics, telescope design, space, spectroscopy and solar power.

Arguably, he is the reason that for many decades, Tucson was considered to be the center of astronomical research, and the reason it is still called "Optics Valley", from the effects still felt by locating of Kitt Peak National Observatory and OSC within a city block of Steward Observatory..  Having worked at all 3 institutions he served, I can honestly say that without his leadership, would I even be located in Tucson?  A valid question, for which an answer is not forthcoming.

I met Aden only briefly on 2 occasions, but am overjoyed I was able to hear his presentation last year on why Kitt Peak was chosen.  It was magical to be transported back those 50 years and look over his shoulder to the home movies and photos he took on that first horseback ride up the mountain.  He told the story of that frigid November night and the return trip fall off his horse, breaking his arm, doing little to blunt his enthusiasm for the place, which still excites me as well.  We've lost a true visionary, and the great institutions that line the intersection of Cherry and University on the UA campus are perhaps a lasting tribute.