ASTRONOMY CLUB OF TULSA

OBSERVER

E-mail version

December 1999

ACT, Inc. has been meeting continuously since 1937 and was incorporated in 1986. It consists of approximately 150 members and is a nonprofit; tax deductible organization dedicated to promoting, to the public, the art of viewing and the scientific aspect of astronomy.

WHAT:

The Astronomy Club of Tulsa Meeting

WHEN:

Friday December 17th, 1999 at 7:30 P.M.

WHERE:

Room M1 inside Keplinger Hall, the Science & Engineering Building at TU. Enter the parking lot on the East Side of Keplinger Hall from Harvard and 5th Street. This will take you directly toward the staircase to enter the building. Room M1 is the first room on the left.

FROM THE PRESIDENT

Hello Fellow astronomers

I hope this letter finds you looking forward to sharing all the exciting things you have seen over the past month. WOW! Has there ever been a month so packed with cosmic anticipation! We had great a turn out at both the TCC public Star Party and the Air and Space Center nights. The sky was prefect both nights. If you didn't get a chance to hear Dr. Goldstien or Dr. Thaller you missed a real treat. I have some "inside Information" on why we haven't heard from Mars that I'll let you in on. The Mercury Transit Nov 15th was great. I'll try to have a replay of this celestial intersection for you at the Dec. 17th meeting. The Astronomy Club hosted 43 teachers from around the country at the NSTA teacher's convention on Thurs Nov 18. They gave us a generous donation toward our observatory. The Leonid Meteor shower was kind of a let down but wasn't the anticipation grand! They tell me over 400 people showed up at the observatory to see that one. Hopefully the more reliable Geminid Meteor Shower this weekend will satisfy our craving for cosmic fireworks.

Our plan for the Fri Dec 17th meeting is to share our observations and experiences from these events. If you have pictures, slides or video please contact me (astroland@gbronoline.com) and bring them to the meeting. Any of you who went to the fall astronomy conventions are welcome to share also. OKIE-TEX, Mt. Magazine or others? Dean Salman will be sharing how to construct a windbreak from these chill winter nights and I will be sharing my experiences at the Atoka star party in last October. Hope to see you all there.

Jan 21st will be our first meeting of the new millennium. We are going to do a workshop for new or novice owners of telescopes. If you know anyone who got a new telescope for Christmas invite him or her to come. We plan to give them some tips how to use their equipment and help them avoid some common pitfalls. Think back to your first telescope and how you would have benefited from some experienced advice to get started. Also we will try to build off the enthusiasm of the TOTAL LUNAR ECLIPSE on Thurs Jan 20 to welcome new faces to our club.

These are our planned meeting Dates in 2000.

Jan 21 - Feb 18 - Mar 17 - April 14 (Do your taxes Early) - May 19 and June 16

Bring your Ideas for great meetings in 2000.

Your Y2K (non-compliant) President John Land

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BRIGHT MOON

This year the full moon will occur on the Winter Soltice (December 22nd), called the first day of winter. Since the full moon on the winter solstice will occur in conjunction with a lunar perigee (point in the moon's orbit that is closest to Earth), the moon will appear about 14% larger than it does at apogee (the point in it's elliptical orbit that is farthest from the Earth). Since the Earth is also several million miles closer to the sun at this time of the year than in the summer, sunlight striking the moon is about 7% stronger, making it brighter. Also, this will be the closest perigee of the Moon of the year since the moon's orbit is constantly deforming. If the weather is clear and there is a snow cover where you live, it is believed that car headlights will be superfluous.

In laymen's terms, it will be a super bright full moon, much more than the usual AND it hasn't happened this way for 133 years!

Our ancestors 133 years ago saw this. Our descendants 100 or so years from now will see this again.

I hope someone else might find this interesting! Remember this will happen December 22, 1999.....

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December SKY FORUM

By Don Cole

Many apologies from this end for not contributing over the past month or so, but my work schedule did not allow the time for it. However I will try to do better.

Looking now at some objects just slightly farther away than our galaxy we see the Quasar, this is an acronym for quasi-stellar radio source, usually any of the blue, star-like objects that are strong radio emitters and the spectra of which exhibit a strong red shift. Quasars were identified as sources of intense radio emission in the late 1950s. In 1960, using the 200-in. (508-cm) telescope on Mount Palomar in California to observe the positions of these radio sources, astronomers discovered objects the spectra of which showed emission lines that could not be identified. In 1963 the Dutch-American astronomer Maarten Schmidt discovered that these unidentified emission lines in the spectrum of quasar 3C 273 were known lines that exhibited a far stronger red shift than in any other known object.

One known cause of red shift is the Doppler effect, (see Doppler shift below) which shifts the wavelength of emitted light of celestial objects toward the red (longer wavelengths) when the objects are moving away from the earth because of the expansion of the universe. This red shift (See red shift below) is called cosmological, and from the amount of red shift astronomers can calculate the recession velocity. Hubble's law, which states that recession velocity caused by the expansion of the universe is directly proportional to the distance of the object, indicates that quasar 3C 273 is 1.5 billion light-years from the earth.

By the end of the 1980s, several thousand quasars had been identified and the red shifts of a few hundred determined; in a small number of these, the shift factor is greater than 4. If the red shift is assumed to be cosmological, these quasars would have velocities greater than 93 percent of that of light. According to Hubble's law, their distances would thus be greater than 10 billion light-years, and their observed light would have been traveling practically as long as the age of the universe. In 1991 a quasar 12 billion light-years distant was discovered by observers at Palomar Observatory. Judging from the energy received on earth from such distant objects, some quasars produce more energy than 2000 ordinary galaxies-one, S50014 + 81, may be 60,000 times as bright as the Milky Way. Radio measurements, however, combined with the fact that electromagnetic waves emitted by some quasars vary strongly over a period of a few months, indicate that quasars must be much smaller than ordinary galaxies. Because the size of a fluctuating radiation source cannot be much larger than the distance light would travel from one end of the object to the other during one fluctuation period, astronomers estimate that the variable quasars cannot be larger than one light-year across, which is 100,000 times smaller than the Milky Way.

No satisfying explanation exists for a mechanism that could produce such amounts of energy in a relatively small volume. For this reason, some astronomers suspect that the red shifts in quasars are caused by some other mechanism than the Doppler effect, and that quasars are not really very distant. The American astronomer Halton C. Arp, for example, has found large differences in red shifts in quasars and other galaxies that appear to be physically linked. In many other apparent pairings of quasars and ordinary galaxies, however, the red shifts do correspond. One theory gaining wide acceptance is that quasars are the superluminous cores of galaxies and that they and radio galaxies may actually be equivalent objects seen from different angles.

*** Astronomy Dictionary ***

Doppler Effect: In physics, the apparent variation in frequency of any emitted wave, such as a wave of light or sound, as the source of the wave approaches or moves away, relative to an observer. The effect takes its name from the Austrian physicist Christian Johann Doppler, who first stated the physical principle in 1842. Doppler's principle explains why, if a source of sound of a constant pitch is moving toward an observer, the sound seems higher in pitch, whereas if the source is moving away it seems lower. This change in pitch can be heard by an observer listening to the whistle of an express train from a station platform or another train. The lines in the spectrum of a luminous body such as a star are similarly shifted toward the violet if the distance between the star and the earth is decreasing and toward the red if the distance is increasing. By measuring this shift, the relative motion of the earth and the star can be calculated.

Red Shift: The shift of light waves toward longer wavelengths observed in the lines of spectra of celestial objects. The American astronomer Edwin Powell Hubble, in 1929, linked the red shift observed in spectra of galaxies to the expansion of the universe. Hubble theorized that this red shift, called the cosmological red shift, is caused by the Doppler effect and hence indicates the speed of recession of the galaxies-and, by using Hubble's law, the distances of the galaxies.

A second mechanism for the red shift is the gravitational red shift, also called the Einstein shift. It was predicted by Albert Einstein's general relativity theory, according to which periodic processes are slowed down in a gravitational field. The Einstein shift is noticeable in the spectra of compact massive stars, such as white dwarfs.

The large red shifts observed in quasars are generally believed to be cosmological. Some scientists, however, believe that the red shifts in quasars are caused by the Einstein shift or by another unknown mechanism.

So until next month Dark Skies and Steady Seeing to You.

Reference Material :: "Astronomy, A self-teaching guide." by Dinah L. Moche (4th ed.) "Guide to the Stars" by Leslie Peltier. " Astronomy, For the Earth to the Universe" by Jay M. Pasachoff (3rd ed.)

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DAVID'S ASTRO CORNER - "The Leonid Meteor Dribble".

By David Stine

I am sure everyone saw the movie "Field of Dreams". Remember the saying "build it and they will come". Well that was what we found out at the observatory last month. "Have a meteor shower and they will come, and come, and come, and continue coming." The word got out through the media that the Leonid Meteor Shower was going to be spectacular and that the best place to watch for meteors was at the Astronomy Club of Tulsa observatory. Now that's fine except the observatory can only accommodate a couple of hundred people at one time and that's pushing it. If you remember the last seen of Field of Dreams where the camera pans out and you see this line of cars with their headlights on coming to the baseball field, that's the way it looked about 11p.m., a line of cars coming up the hill to the observatory. Both KOTV and KJRH did live broadcasts from the observatory. It was good publicity for the club, but it also caused crowd problems. At one time I counted 104 vehicles parked in the AT&T lot, the observatory lot, and all along the road. An estimated 450 people came out of the woodwork to view the expected shower. At least we know now that the general public will drive that far to come to the observatory if we ever decide to have a public event there. The only problem we had for these people was "no meteors or at the very most 3 or 4 an hour during the time frame most people were there 9-1a.m. Gerry kept them occupied viewing the moon, Jupiter, etc. through the clubs observatory scope. There were a few bright meteors that were seen by the public, so most left satisfied that they had seen a Leonid Meteor Shower, so the night was not a complete loss to them. I think the most impressive aspect to most was being able to see so many stars even with the moon's light. Patience helps for meteor showers. Wait long enough and you are bound to see something. After most people had left and only us die-hards were left, we did have a little over an hour of a decent shower between 3:30a.m.-5a.m. We counted 8 5 meteors during this brief outburst. There weren't any bolides like last year, but it was worth the wait. And oh what a sky at that time of night, no moonlight, and a sky a blaze with stars. Earlier in the evening, several of us tried to see if we could detect meteor flashes on the dark side of the moon through our telescopes. K.C. thought she saw one and I kept seeing something, but we really couldn't confirm it or not. In Houston a video did confirm a 1st Mg. flash and several others across the world confirmed flashes.

This year's storm actually did happen in the location and time predicted by David Asher and Robert McNaught. The Middle East and Europe was where to be. At one time, observers in France and Spain saw meteors coming at a rate of 30 per minute which corresponds to a zenithal hourly rate of 5,000. Most estimates from across that area of the world were 2,000/hr. Asher and McNaught predicted a peak at 2:08UT. The actual peak was 2:04UT. And they predicted that the US would only see about 20/hr., which was basically what happened except for the brief outburst. Now for the good news. Next year Asher and McNaught have predicted two possible peaks, the first would put it in Europe and Africa, but the second peak is predicted for 7:51UT or our time 1:51A.M. CST. The radiant is up in the East and we are in the ballpark. They expect the rates to be 100-5,000/hr on the morning of November 18. As I said before with meteor showers, patience is golden. In 2001, the morning of November 18th, at 10:01UT or 4:01a.m. our time we could see as many as 2500/hr. Later that day Eastern Asia and the Western Pacific is predicted to see 10,000-35,000/hr. Then in 2002, our boys have predicted a 25,000/hr storm with the peak on November 19 at 10:36UT or 4:36a.m. our time. At that time Leo is high in the East, what a spectacle that will be if McNaught's and Asher's predictions hold up. So maybe the best is yet to come.

If you get this before December 13th, don't forget the annual Geminid Meteor Shower. It is expected to peak on the morning of December 14th at 11hUT which is 4a.m.CST. At this time you should be able to see 90-120 meteors/hr from a dark location. However, you don't have to wait until the early morning hrs to see a flow of meteors. This is one of the finest and dependable showers of all the meteor showers. The radiant in the constellation Gemini is well up in the East by early evening on the 13th, so you should be able to see many meteors between 9 and midnight even though the peak won't be until the early morning. Geminids are slow moving(35/km/sec.)compared to other meteors such as the Leonids. This results in longer lasting trains and colors and they are much easier to follow. Geminids always produce several bright bolides with trains stretching across the heavens. I'm sure there will be club members donning their parkas and hot chocolate and heading for the observatory on the night of the 13th. Hope to see you there.

NOVA ALERT - On Dec. 1, Alfredo Pereira discovered a new star with binoculars about 2 degrees NNW of Delta Aquila. The Nova's location is RA - 19h 23m 05.38 sec. DEC - +4d 57' 20.1". What makes this Nova exciting is that at discovery it was at Mg. 6.0 and just over the last few days after discovery it has been reported as bright as 4.0 Mg. It is well placed for Tulsa observers in the early evening. Tulsa Astronomy Club members, K.C. Lobrecht and Gerry Andries observed the Nova on December 3. K.C. said after finding 3rd Mg. Delta Aquilae she located the new star fairly easily with her 13.1 inch Dobsonian. The new star looked nebulous and about 4th Mg. The latest report from SKY said the nova has faded to about Mg. 5.4 as of Monday Dec. 6. It should remain visible through December. By the time you read this the star may have brightened even further or it may have dimmed.

Congratulations to K.C. Lobrecht for an outstanding achievement. She recently completed the Herschel II observing program. She is the first female to accomplish this feat and only the 10th person on record since the observing program began according to the Astronomical League. I will be talking more about the Astronomical Leagues observing programs in future issues and how you can earn observing certificates. That's it from my Astro Corner this month.

That’s all folks…