ASTRONOMY CLUB OF TULSA

OBSERVER

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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.

The Astronomy Club of Tulsa Meeting

Friday April 30, 1999 at 7:30 P.M.

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

Rusty Fletcher, our new club president, will be giving a presentation on, "Computer Software and Astronomy". Rusty has been a very avid amateur Astronomer for over 25 years and is the owner of Computer Works in Broken Arrow, Ok. He has built three telescopes including a 17.5-inch Dobsonian, which he currently links to a computer to navigate throughout the sky. Rusty will be demonstrating both simple and sophisticated astronomy programs for everyone to observe. He will also give Internet addresses where astronomy programs can be obtained for free.

Tut Campbell from Russelville, Arkansas gave an outstanding presentation on his super-nova patrol search and his research on cataclysmic variables. He also gave us some information about light pollution near the end of the meeting. Tut explained in detail how he searches for super-nova using a 12-inch Meade LX200 and an ST6 CCD camera. Using the computer and digital projector in our new meeting room (M1), he accessed the Internet presenting charts and pictures along with physical demonstrations. He showed us how cataclysmic variables evolve and what causes them to occur. Thank you Tut for a very informative and enjoyable evening!

I must admit I never thought I would become president of The Astronomy Club of Tulsa when I was elected vice-president last October. I guess no one anticipated Kevin Manning would be leaving us this summer and moving to Boston. I appreciate the hard work and energy Kevin has put into this club over the past year and a half as president. I know that he loves ACT and wants to see it move forward in a positive and productive manner. Thank you Kevin for everything you have done to make The Astronomy Club of Tulsa a better place for all of us.

I am very happy to report that Ron Wood is now home and improving. The Messier Marathon that is usually held at Ron's farm had to be cancelled this spring as a result of his accident. We are still planning to reschedule it latter this summer.

As the new president of ACT, I want to assure you that I plan to do whatever it takes to see that things continue to move forward in a direction that is best for the club. Please know that every member can feel free to express their ideas, contact me anytime, and enjoy being part of what's happening both at the observatory and at the club meetings. Let's have fun sharing our love for astronomy!

Rusty Fletcher

On Friday Night, May 14th, the ACT Club star party will be held at the RMCC Observatory. All club members, their families, and friends are welcome. The sun sets at 8:22 PM that evening, so the Observatory facility should be open by about 7:45 PM for everyone who wants to set up their personal telescope. For directions to the Observatory or in case of questionable weather call Gerry Andries at: 918-Phone.

May 28, June 25, July 30

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By David Stine

Something to think about, if your mind can even comprehends what I am about to tell you. Did you know that when Spacewatch telescope came into existence, the rate of comet and asteroid discoveries that were made came at an astonishing rate? Almost 14,000 discoveries in five years. We thought, man this is unbelievable, nothing can compare to this observing masterpiece. Well, only a few years later and only a year of observing, Spacewatch's record was passed, smashed, and destroyed. In just one year the space telescope Linear had discovered almost 20,000 comets and asteroids! That's an average of 54 objects per night. I don't think any of us observe 54 known objects in a month. Think about it, and we are only scraping the edge of the enormous unconceivable universe. What lays ahead? At the rate we are developing new technology, its anybody's guess, a million discovered every second, don't laugh it could happen before you could blink your eye.

Guess what, we are not made of comets as some astronomers led you to believe. Recent results show that the chemical composition of water in comets, specifically Comet Hale-Bopp, does not match the water that covers the earth. The difference is in the ratio of heavy water, in which one of the hydrogen atoms in H20 has an extra neutron. In other words, the water in Hale-Bopp has much more heavy water than the Earth currently does. According to Geoff Blake, Caltech astronomer, this implies that the water in our rivers, lakes, the oceans and ourselves did not originate from cometary impacts. Maybe, but has anyone asked the question, could Hale-Bopp be a one of a kind comet, where other comets might have the same ratio of heavy water as Earth? Hopefully Stardust will have the final answer in a few years.

MARS ALERT- Mars is now in great position for observing in the evenings in April and May. Just recently amateur astronomers saw clouds over Olympus Mons. An alert was sent out by the Association of Lunar and Planetary Observers for you to observe, sketch and photograph this unusual and new feature in the region of Ascraeus Lacus and Nix Olympica. If you are not sure where to find Mars, just look to the SE after dark, you can't miss it, the brightest object in that area with an orange, reddish tint to it. Also it doesn't twinkle like stars do. Check April's Sky and Telescope for more information on observing the red planet.

It seems that it is almost impossible to keep up with the discoveries that astronomers are making daily. Just this morning I watched a news program on TV where it was announced that not only had one new planet had been discovered, but a whole solar system. Three planets very near the star Epsilon Andromeda have been detected. What is so unusual about them is their size. All but the one nearest Epsilon dwarfs Jupiter our largest planet. As for water or life as we know it on any of the new bodies, it is highly unlikely as the closer planet is too hot and the other two are two cold to support life. However, there may be an undetected moon orbiting the second planet that could be just the right distance from the star, which could be similar to earth. Oh by the way, Epsilon is a 4th Mg. star, so it is visible and will make a good object to show people at future star parties when Andromeda is in the sky.

Just recently the farthermost galaxy ever detected, named Sharon after its discoverer, who incidentally is a woman astronomer, was detected only a million years after the Big Bang. We are going deeper and deeper into our Universe and getting closer to the beginning. Sharon is already going to have a short reign as the farthest galaxy as five more are being analyzed as we speak that have been reported even deeper into the Universe. Will we detect the actual Big Bang, it's only a matter of time.

Closer to home, Joe Dellinger was able to observe the graze of the star Aldebaran by the Moon Sunday night, April 18. Joe said the star went out for about 10 seconds, then reappeared for half a second, then went out again for a couple of minutes. At this point clouds covered the moon and the show was over, but what a show. With Venus near by it was a beautiful view. This was the last naked eye gaze or occult of a bright star by the moon this century. So if you didn't see it you have to wait until 2005 for another one. Well not exactly, you can see the moon occult Regulus on May 21/22, then you have to wait until 2005.

Have you ever seen an asteroid? Well on May 5, find Venus which shouldn't be too difficult at -4.2 Mag., then looking 0.7 degrees north of the planet and with a telescope or binoculars you should be able to see the 8.9mg. asteroid Ceres. The asteroid should show movement after a few minutes, enabling you to detect it from the background stars. Another chance to see an asteroid comes between May 20-25. Find the spiral galaxy NGC2903 in Leo, one of my favorites, just SW of the end star on the crook of the question mark. On May 23 the 7.8mg. asteroid Vesta lies only 30 minutes south of the galaxy. To those familiar with the NGC2903 area, it could be mistaken for a supernova if one is not aware that Vesta will be passing by.

Last but not least, Ron Wood is back home now and progressing very well. The blood vessels which are essential for a successful skin graft are starting to grow which is the good news. Maura said you can see them like little pink buds. After enough of the vessels take hold then the grafting can begin. The Messier Marathon had to be cancelled again but Maura says when Ron is well and able again, a big summer star party with their Tulsa and Tuva friends hopefully will be in store for all.

That's it from my Astro Corner this month.

By Don Cole

Many apologizes, I completely missed last months deadline for the newsletter. However, here it is for this month. P.S., I almost missed this month too.

Uranus, is a major planet in the solar system, equivalent in brightness to a sixth-magnitude star. It ranks seventh in order of distance from the sun, revolving outside the orbit of Saturn and inside the orbit of Neptune. Uranus was accidentally discovered in 1781 by the British astronomer Sir William Herschel and was originally named the Georgium Sidus (Star of George) in honor of his royal patron, King George III of Great Britain. The planet was later, for a time, called Herschel in honor of its discoverer. The name Uranus, which was first proposed by the German astronomer Johann Elert Bode (1747-1826), was in use by the late 19th century.

Uranus has a diameter of 52,200 km (32,500 mi), and its mean distance from the sun is 2.87 billion km (1.78 billion mi). Uranus takes 84 years for a single revolution, or orbit, and 17 hr 15 min for a complete rotation about its axis, which is inclined 98 degrees to the plane of the planet's orbit around the sun. Uranus's atmosphere consists largely of hydrogen and helium, with a trace of methane. Through a telescope the planet appears as a small, bluish-green disk with a faint green periphery. Compared to the earth, Uranus has a mass 14.5 times greater, a volume 67 times greater, and a gravity 1.17 times greater. Uranus's magnetic field, however, is only a tenth as strong as earth's, with an axis tilted 55 degrees from the rotational axis. The density of Uranus is approximately 1.2.

In 1977, while recording the occultation of a star behind the planet, the American astronomer James L. Elliot (1943- ) discovered the presence of five rings encircling the equator of Uranus. Named Alpha, Beta, Gamma, Delta, and Epsilon (starting from the innermost ring), they form a 9400-km- (5840-mi-) wide belt extending to 51,300 km (31,860 mi) from the planet's center. Four more rings were discovered in January 1986 during the exploratory flight of Voyager 2.

In addition to its rings, Uranus has 15 satellites (the last 10 discovered by Voyager 2); all revolve about its equator and move with the planet in an east-west direction. The two largest moons, Oberon and Titania, were discovered by Herschel in 1787. The next two, Umbriel and Ariel, were found in 1851 by the British astronomer William Lassell (1799-1880). Miranda, thought before 1986 to be the innermost moon, was discovered in 1948 by the American astronomer Gerard Peter Kuiper.

*** Astronomy Dictionary***

RR LYRAE STAR : A type of yellow giant pulsating variable, with a period of 0.2 - 1.2 days and an amplitude of 0.2-2.0 magnitude. This star belongs to population II that lies in the galactic halo and globular clusters (which gives rise to their earlier name of cluster variables).

CYGNUS LOOP : A large supernova remnant in the constellation Cygnus at the estimated distance of 2000 light years. The loop is 3 degrees across and is expanding at over 100 km/s and estimated at around 30,000 years old. Radio, infrared, and x-ray maps show the complete loop structure. However, optical scopes show only small fragments, one of which is the "Veil nebula".

>>> From The Cargo Bay <<<

How long (minutes) into the flight (after launch) are the SRB's jettisoned? At T-3.8 seconds the computer gives the command to start the three main shuttle engines. The first starts at T- 3.46 seconds and the other two at 120 millisecond intervals. As the main engines come to 90 percent power the STS stack sways or (twangs) about 40 inches from side to side in the direction of the main fuel tank. At T-0 seconds the thrust is at 90 percent and a timer is started for 2.64 seconds, as it reaches zero, the SRB's ignite. The 2.64 second delay is to allow the STS stack to be upright at the moment the SRB's ignite. After all engines are operating, liftoff occurs at T+3.0 seconds. Eight seconds after liftoff the shuttle rolls 120 degrees to the right for a heads down climb to orbit. 50 seconds into the flight Mach-1 occurs. At T+2 minutes 12 seconds the SRB's have expended their supply of solid fuel and are jettisoned, Mach 4.5 occurs at an altitude of about 28 miles. Who is the person (what position) that actually presses the "Launch" button, when the shuttle is launched? Nobody actually presses a "Launch" button. At T-25 seconds all launch commands and procedures are handed over to the mission control and shuttle onboard computers. At T-3.8 seconds "ignition". Question : Once the orbiter is on station in orbit "Why are the orbiter cargo bay doors opened"?

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.)

The club will meet the last Friday of each month except for November and December when a holiday will interfere with the last Friday. The November meeting will be on the 19th, and the December meeting will be on the 17th.

The dates are:

30 April

28 May

25 June

30 July

27 August

24 September

29 October

19 November

17 December