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AVAS News &
Meetings |
AVAS Met at Collegiate Peaks Overlook
The Arkansas Valley Astronomical Society met at 7:30 PM on May 2 at the Collegiate Peaks Overlook Site. We had very clear weather, for once, but the wind was VERY cold. In fact, when I got back home and stopped shivering, I checked Canadian weather. It was colder in Buena Vista than it was in Yellowknife, NWT!
The date of May 2 was selected because Mercury will be passing very near (just to the south) of the Pleiades, and the combination of the planet and bright stars provides an excellent sight. A week later, on May 9, Mercury will actually be further from the sun, but it will not be as bright (the sky will be darker before it sets, so visibility will be about the same). Also, it will not be close to a star cluster.
But, if you have never seen Mercury, and can get to a site with a clear view to the west, it remains well worth your time to go out and take a look. Who knows, you might find it to be warmer..
For further questions or comments, call Sue and Frank Snively at (719) 395-0605.
Something well worth watching
There is a very interesting web site you can take a look at. Dr John Dubinski, a professor at U. of Toronto, happens to have the largest "supercomputer" in Canada, and has used the facility to model the dynamic behavior of galaxies. No, he can't analyze all the hundred billion stars in something like our Milky Way or Andromeda, but he can track the behavior of, perhaps, several hundred thousand stars as they interact through gravity with each other. He has several simulations of colliding galaxies - note that the average separation of stars is so large that the galaxies pass through each other - and then "bounce" and ultimately form giant elliptical galaxies.
It is quite wonderful to watch.
The URL for the visual treats is:
http://www.galaxydynamics.org/gravitas.html
Rather than feel bad about inclement weather, and doing something desperate like watching TV, it is well worth using the computer for a look at several of the dynamic simulations.
The Sloan Digital Sky Survey Is Available
The Arkansas Valley Astronomical Society met at the home of Frank and Sue Snively on the evening of July 13. Dr Kurt Anderson, Director of the Apache Point Observatory in New Mexico, talked about the activities at Apache Point, especially the Sloan Sky Survey, which uses a special dedicated telescope. The data from the Sky Survey is processed at Fermilab in Illinois, and is available to the public. There is far too data much for any single astronomer or group to study in detail. The reduced data are available On Line, for public access. The URL is
http://www.sdss.org
There is a good bit of information on the web site which is accessable to the "normal" Mac and Windows users, which is most of us. I was personally reluctant to try to get into the UNIX oriented data files, since they would tie up a "home use" broadband connection (I use a cable modem, myself), and rapidly exceed the capacity of my Hard Drives. Maybe some day..
It would be nice to find something worth publishing in "Astrophysical Journal". The data are there. All we need is a dedicated (fast) home computer and plenty of storage capacity. Well a 1000 baseT Ethernet connection would be handy, also.
What constitutes a "good" viewing night?
Of course, there is no unique answer to the question. However, there are some things that will help you see the heavens more clearly. And some simple checks you can make. If you want to see, photograph, or just explore the sky, there are some nights that are easier to live with. That is especially true if you are looking for faint objects, or if you would like to do some photography.
First, it should be dark. That means that the moon, especially if it is nearly full, should not be up. Many of us have to tolerate street lights, signs or fearful neighbors who feel better with the yard brightly lit. Those things are bad, but if the moon is shining also, almost everything is wiped out. There are a couple quick checks I use. First, the two stars that make the inside of the bowl of the Little Dipper, which are dimmer than 4'th magnitude, should be visible. Second, the nucleus of the Andromeda Galaxy, should be visible if someone shows you where to look (it is also 4'th magnitude, but is more difficult to see, since it is a diffuse patch, not a sharp point).
Second, the stars should not be twinkling. If wind or rising warm air are stirring the atmosphere, the images will "dance", and you will not be able to see close pairs or any detail of a diffuse object.
The twinkling was most bothersome to me when Mars made its last conjunction. It was low in the southern sky, and since it was summer, the warm ground was sending up heat waves. I could see the bright planet, but when I used a telescope, I could only think of a bowl of orange Jello (TM) being shaken.
I will have to write another essay on suggestions for what to look at in adverse conditions.
And What to do if There is Haze, Light Pollution, and Such?
There are still things to do unless it is clouded over. The bright planets, namely Venus, Jupiter and Saturn are worth looking at, if you can see them at all. To be sure, Venus is a bit of a washout, since all you can see is that it has phases, a thin crescent when it is close to the earth, an almost full disk when it nears opposition (i.e. the other side of the sun), and everything in between. Jupiter and Saturn put on a good show almost any time.
A personal anecdote: I didn't do much star gazing until I went out to California to attend graduate school. A friend of mine who knew his way around campus (he had been an undergraduate at Caltech, also) asked me, one evening, "What's that bright thing in the sky?" "I dunno." "Let's take a look", he said.
Like most graduates of Caltech, he had a collection of keys, and we went to the 1/10 scale model of the Palomar telescope, which had been built to support detail design of such things as the pointing and tracking system. It was always used as a Cassegrain, since only 20 inches diameter would not support a built-in observer's cage at prime focus. Using the spotter scope, which needed cleaning badly, we located the bright object and looked in the main scope. There, with the rings glowing nicely, was Saturn. I still remember the thrill. And with the collecting area that comes with 20 inch diameter, it was quite bright. In later years, with lesser telescopes (my own is 8 inch diameter) I have also looked at Jupiter on many occasions.
And the moon is well worth looking at, as well. That is especially true several days before or after full moon. The craters near the terminator (i.e. the shadow line) are thrown into sharp relief by the sun which is close to the local horizon. Most of the larger ones have been named, and you can look at a diagram of the moon's surface to try to answer the question "What's that one called?" Of course, a good many smaller ones remain nameless.
A good many people stick a dark filter into the eyepiece when they are looking at the moon. It enhances the contrast, especially when the moon is nearly full. Note well, however, that there is no danger of actually harming your eye. The actual surface brightness of the moon is about the same as that of old worn pavement with the sun shining on it.
Two AVAS Astronomy Articles!
Frank Snively, President of AVAS, discusses how we know if the color in a photo taken from space is accurate. Also, Jeff Beaty presents an interactive panorama of the surface of Mars as seen from the Spirit rover. Check out the Astronomy Articles Page.
A New Observatory is Coming to a Valley Near You
For the latest information, visit the web site given below.
As a reminder of what is being used: The primary mirror of the telescope (about 30 inches diameter) is ground from a disk of low expansion glass, and is carefully mounted for vibration isolation and thermal isolation. The Cassegrain reflector is mounted on a number of steel posts which extend from the primary support. It is interesting to note that the Cassegrain position has a motor control - necessary because the thermal expansion of the support is quite different from that of the mirrors, and the telescope would go out of focus as the temperature changes.
The local promoters have made arrangements with a faculty member at the University of Dallas to procure CCD imaging and spectroscopic equipment, which will make the telescope useful for a variety of research programs.
Alas, while the observatory building has been constructed, the electronic equipment has yet to be installed and checked out. Such delays are part and parcel of any new installation, unfortunately.
We note in passing that other observatories have also encountered delay. Perhaps the most noteworthy was the Hale Telescope at Palomar Mountain. The 200 inch mirror blank was delivered to Pasadena in the late 1930's, and it was being ground and polished, always a slow process. And it became slower after the Japanese attack on Pearl Harbor. In fact, the effort in Pasadena was diverted to protecting the mirror, which was the most expensive piece of scientific apparatus in the world. It was carefully packed away under many tons of sand bags, and then the workers went off to war. In 1945, the sandbags were removed, the grinding and polishing equipment was re-installed, and work continued until late 1948, when the mirror was shipped up the mountain.
We trust that the installation of the telescope and its accessories in Gunnison will not be so long delayed.
For more information, use the link on the AVAS home page to go to "coloradoskies.org".
A Caution Regarding Arkansas Headwaters Recreation Sites
The Stone Bridge site near Salida, and the Railroad Bridge site north of Buena Vista are both excellent for viewing. We will continue to use them but it will cost us.
With the tremendous budgetary squeeze on all public institutions in Colorado, it is mandatory that everyone pay the required $2.00 per person admission to events at Arkansas Headwaters Recreation Area sites so that they can continue to keep them open.
An alternative is to purchase an annual permit for $27.00.
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Buena Vista Area Sky Chart
