Br. Consolmagno Lecture at the Adler... Feb 11, 2007 3:05:30 GMT -6
Post by Chicago Astronomer Joe on Feb 11, 2007 3:05:30 GMT -6
Vatican Astronomer Lecture at the Adler
Here Br. Consolmagno and I shake a hearty greeting
Br. Guy Consolmagno visits Chicago at least once a year and gives a great talk at the Adler Planetarium. I have been fortunate to attend three of his lectures, and this latest one on 07 February 2007 was very interesting.
The following images were taken from my angled seat, ergo the elongated pics. All images taken of the screen are from Br. Consolmagno presentation.
The lecture started with a talk about light. In that sometimes it behaves like a particle, and sometimes it likes to be more like a wave. Knowing this, observations of distant objects can be studied as the different wavelengths sometimes collide and tell us certain characteristics of objects.
For the longest, man studied the heavens and called it Astronomy, until one man put a prism in front of the objective lens of a telescope in the 1860's and changed astronomy into astro-physics. This astronomer was Angelo Secchi. We then started to study what the cosmos were made of, with color being the main tool of discovery.
An interesting observation was shared by Br. Consolmagno, in that we all know that signals of "I Love Lucy" are racing away from us and civilizations 50 light years away are evaluating us by our tv programs. Radio waves stay within our atmosphere, and ergo, we can listen to distant radio programs from hundreds of miles away due to the "bouncing" effects that our air/ionosphere provides. This is good and bad. More on that later.
But, with recent developments of the internet, satellite and cable entertainment, the signals that were once strong and prevalent, are now starting to fade and weaken. A distant world might take this as the slow end of an advanced civilization.
The blanket of air that surrounds us also absorbs certain wavelengths of radiation. Methane from cows being the main producer of the gas interferes with spectroscopy and water vapor absorbs Infrared radiation - hindering our ground based observations.
The Vatican Observatory
The best solution is to rise above the atmosphere, ala Hubble and Spitzer, but time on the instruments are doled out with an eyedropper. The next best thing is to build observatories as high and away from urban areas as we can. The Vatican desired such an observatory, but most European locales are light polluted. A politically stable, dry and mostly sunny place is Mt. Graham in Arizona USA.
Br. Consolmagno explained that the most expensive part of building an observatory is not the instrument - mirror, but the building itself! As the materials and labor must be transported along narrow and high locations. But back to the mirror.
A new development in constructing mirrors was developed in where the entire glass base, (once hand/machine crafted), is spun around in huge centrifugal machines and the edges raised to a parabola shape. It is then coated with reflective material and put to service. The Vatican observatory has the first spun mirror created. The man who developed this technique is Roger Angel, and it is now said that the Pope's Telescope was created by an "Angel".
Optical System : aplanatic Gregorian, f/9
Focal Length : 16.48 m
Primary Mirror : f/1.0, Diameter 1.83 meters
Secondary Mirror : f/0.9, Diameter 0.38 meters
Back Focal Distance : 50.80 mm (effective)
Vignetting-Free Field : 72 mm diameter (15 arcmin)
Image Scale : 12.52 arcsec/mm
Image quality : 0.1 arcsec throughout 6.8 arcmin
diameter flat FOV
Mount : altitude-azimuth with derotator
What surprises me is the computer:
PCs: Pentium II PC with Linux and NT
The talk now focused on the Vatican telescope or VATT (Vatican Advanced Technology Telescope). We astronomers are used to hovering over our telescopes in catching views of our desired targets, but this is not the way at the VATT. The telescope does not operate in the manner we are used to, as it does not even have eyepieces! And the astronomers never actually come close to it while observing, as the temperatures around the scope must be kept at the ambient temp of the surrounding environment. People gathering around the scope would greatly disrupt this carefully controlled area. Great huge fans run constantly and it's quite noisy.
Observations or more exactly "Exposures" are taken one floor away from the scope. Above you can see "Mission Control". It is here where all the work is done, as each monitor controls some aspect of the observatory. Dome, camera operation and more are remotely controlled from the computer array shown here.
The preparation to spend time at the VATT consists of stopping at the Safeway and picking up frozen meals.
The evening of observation is pre-planned and exposures usually take five or so minutes and processing about 1 1/2 minutes to see the result.
The Keck Observatory
Br. Consolmagno also shared with the audience his observations at the Keck Observatory at the summit of Mauna Kea in Hawaii. A grand spread of telescopes, time is precious there as well. Ten meters in diameter, the mirror is composed of 36 hexagonal segments that work in concert as a single piece of reflective glass. In comparison, just one of the segments equals the VATT mirror. One must submit a long application and review process to gain some time at the Keck scopes. One in three are successful.
Keck is so high in elevation that it takes two days to acclimate to the thin air. One can push it, but one starts to act goofy and accidents can happen. But the astronomers do not even get near the mighty Keck scopes. The observation room is 48 miles away in a make-shift astronomer town.
The days of long cold nights behind the eyepiece are over in true research astronomy. It's all done behind comfortable walls and thru computer.
Here at Keck, as at the VATT, exposures are done entirely at the control center. There is a staff person to "watch over" the astronomers and guide them in the proper usage of the equipment. Displayed at the presentation were time exposures of the astronomers doing "Time exposures" thruout the night. Hour after hour of 5/10 minute exposures...it can get pretty tedious.
The rewards are exposures like this one.
This is a RAW exposure image before any post-processing. The heavy streak is a moth that got in the way. A lot of insects to contend with in CCD astronomy. The vertical lines are errors in the CCD wafer-chip. As the chip is made so thin, these lines represent light pouring thru the imperfections. The faults are later removed by computer.
Sometimes the astronomer crew gets rained out, and nothing happens. Hard to deal with after waiting months to get a single evening of scope time. But when they do discover something on a clear night, it's documented and logged. And if it's something unusual - it is sent to the Astro-Physical Journal. Usually, if one submits to a publication such as National Geographic, and it gets printed, you get some sort of payment. Not with the APJ... you pay them!
Observing Distant Objects
All this lead up to Centaurs - or Trans-Neptunian asteroids, and their make-up, behaviors and observations. With the new technologies in observational telescopes, the darkest, smallest objects are not being discovered. Centaurs are both asteroids and comets at the same time. Object 174/P is such an object, discovered in 1986 and coming from the Kuiper belt.
This object demonstrates a peculiar characteristic, in that the coma rotates around the object! This was discovered after months of observation. But it was later discovered that it is indeed two objects, not one orbiting the sun.
With more talk on KBO's and question and answer session, the lecture came to an end. I always enjoy Br. Consolmagno's talks and took some images with him and some of the Adler crew who were in attendance:
From right to left: Fred, Chet, Br. Consolmagno, myself, Jude and Carmen