Auburn Astronomical Society E-Newsletter
April, 1999

Greetings Astrophiles,

In This Issue
April Meeting
Kiesel Park Observatory
Member News
March Observing
WFO Open House
For Your Daily Planner
Wetumpka Crater
Astronomy Day, 1999
Astronomical Primer: Magnitudes
April Meeting
This month's meeting will be on Friday, April 2 at 8:00 PM in room 215 of the Aerospace Engineering building, on the campus of Auburn University. Montgomery area car poolers should meet at my house (518 Seminole Drive). We’ll head for Auburn at 7:00 PM. If you're planning to ride over with us, please e-mail or call (271-3684) so we'll have an idea of how many to expect. Construction on the AE building parking lot continues, so come early, or be prepared for a hike.

 Our normal new moon weekend star party coincides with the Peach State Star Gaze. Several of us will be there, but for those who are not, Holley's Field will be available on Saturday, April 17.

Kiesel Park Observatory
Alan Cook presented his spectacular drawings of the proposed Kiesel Park Observatory, (the round, movable wall-roof design) at the March meeting. As soon as Alan puts the finishing touches on them, they'll be added to the Kiesel Park Observatory page, and you will be notified.
 Member News
Please note Tom McGowan's address change: Mnighttele@aol.comPhillip Hosey is the proud owner of a new Celestron Celestar 8 Deluxe.  After a year of doing his homework and saving his money, 15-year-old AAS friend, Dustin Smith, has ordered an 8" Deep Space Explorer, Dobsonian. We expect some more observing reports soon.
March Observing
March Star Party:  Stormed out again (sigh).  At least this one was easy to call off.
Messier Marathon Monsoon:  The Sun reached the March equinox at 7:46 p.m. CST on Saturday, March 20th, crossing the equator heading north marking the moment when spring begins in the Northern Hemisphere.   Phillip Hosey, Jeff Schaub, and your editor waited optimistically to celebrate the event at Holley's Field that evening.  Phillip and Jeff set up their brand new SCT scopes in a vain attempt to observe at least one object between the clouds.  An hour later, 30 MPH winds warned of an approaching storm.  Five minutes after leaving the field, the rains came.
March 22 Daytime Albebaran Occultation:  Trees on my horizon prevented me from seeing the disappearence, but when the red giant reappeared on the Moon's bright limb, I was surprised to see how easy it was to see against the blue sky with my 80mm f/5.  The reddish hue was obvious.  Anyone else see it?
Walker Ferry Observatory Open House
Scott Thompson invites all AAS members and friends to attend an open house at his Walker Ferry Observatory on Saturday, April 10, 1999, beginning at 6:00 PM. Scott writes: Let’s start before dark, say maybe 30 minutes to an hour. The same time as you would if you were going to Holley’s Field. I want this to be very casual so bring your scopes if you like. Julie, my wife, will make cookies or something for everyone. Stay as late as you like. I can do a 15 - 20 minute talk about the observatory and maybe the ST7 camera. I have not used the camera that much and I am still in the early learning stages. It might be better if I just answer questions. :-) I will be ready either way.

There is not much flat land on my hill. However, there is plenty of flat land in the pasture below the observatory. No cows to contend with! So, if anyone wants to setup out there they can but it is about 100 yards away. If anyone wants to scope all night I will arrange the party house to be open all night with kitchen/tv/heat etc... Just let me know when you arrive. This is a small house down below ours.

I look forward to seeing everyone and I think you will enjoy the visit and tour. It never gets cloudy, foggy, cold, or hot at my house! It’s always pitch dark! We aim to please!

It would be better if we can roll the roof off. Let's postpone if raining. If we have to postpone till May 8 then I will be prepared for rain or shine on that date.

From Hwy. 280 take 63 South and go 4 Miles. There will be the turn off to the left to go to Wind Creek State Park keep going to the next road to the right. This is in front of Mt. Zion Baptist Church. Take a Right onto Walker Ferry Road / County Road 20 and my house is the first drive on the left. Red brick house on the hill.

Going 63 North you will see 2 green houses on the left. The next road to the left just over the hill will be Walker Ferry Road. This is just before the Church ( Mt. Zion Baptist ) on the right. If you pass the Church or the road that goes to Wind Creek State Park you have gone too far. Once on Walker Ferry Road / County Road 20 my house is the first drive on the left. Red brick house on the hill.

For Your Daily Planner
  Shocked Quartz Found at Wetumpka Crater
by Dr. David T King Jr.
Update On Impactites
The impactites in our drill cores displayed interbedded layers of (1) diamictites containing crystalline basement fragments brought up from great depth, (2) impact breccias (containing similar crystalline basement fragments), (3) huge blocks of target rock up to 35 feet thick, and (4) clay-rich sands. Diamictite is a rock that consists of broken pieces of target rocks in a matrix of finely pulverized rock. Impact breccia is a rock that consists of broken pieces of target rocks that generally lack finely pulverized matrix material. Both diamictite and impact breccia are common impactite rocks in the world’s crater-filling units. Huge blocks encountered in drilling were both pieces of deep crystalline basement rocks and chunks overlying softer sedimentary target rocks. Clay-rich sands appear to be a slurry formed from pulverization of the softer sedimentary-rock target material within the impact crater.
Update On Shock Features
Shock features are permanent deformation features imparted to individual minerals owing to the passage of a hypervelocity shock wave coming from the impact cratering event. At Wetumpka impact crater, our microscope slides revealed: shocked quartz (showing two intersecting planes of shock lamellae, a high shock-level indicator and "strong, solid proof" of impact); feldspars that show internal dislocations and crystal damage (looks like "lunar highlands texture" produced by impact events); micas that show dislocations parallel to cleavage (a texture that is either impact-related or due to regional metamorphism); and garnets with internal crush features (a texture that is seen in some impactites, not all).

The shocked quartz is important and is as close as we will ever come to "absolute proof" of the impact origin of Wetumpka. Evidence qualifying as "absolute proof" is hard to come by for geological events that occurred millions of years ago in any sort of investigation, and studying impact events presents some special challenges. Shocked quartz is the highest standard of proof, as it is only found (as far as we know) in impact craters and nuclear weapons test sites. To form, shocked quartz textures require many millions of atmospheres of pressure and those must be applied within a few nanoseconds.

The shocked quartz turned up in the last set of samples that we looked at and were in some of the smallest grains seen under the microscope. They were not very obvious at first and required a lot of looking. I was greatly relieved when I found them a few weeks ago, as I viewed their discovery as finally ending the debate over origin for Wetumpka. The Mayor and her staff were obviously pleased with our discovery, which I announced on February 27 at a City Council meeting and news conference. Dr. Peter Schultz, of Brown University, had reviewed our evidence and the microscope slides the day before and was there at the news conference to back up my claims.

Of my announcement on February 27, I think we can safely say that it has been a long time since a few tiny mineral fragments from deep underground created such an uproar in a small southern town. The avalanche of publicity and interest over the past few days has been amazing.

The complete daily accounts of the core sample drilling as well as this final chapter, is online at:
Astronomy Day, 1999

Correspondence with Rick Evans at the W. A. Gayle Planetarium:

We can work out details later.


And Rick Replied: Russell,

I think it would be a tremendous idea to make it an annual event out here at the planetarium. I am open to suggestions on what we should do this year. If you want to put it before the AAS and get feedback from last year’s participants, on what we could do better, we will do it right! I like the idea of the telescope workshop; we get a lot of questions on that topic.

Let’s consider it a "GO" and start working on the details......


Astronomical Primer: Magnitudes
In the second century BC, the Greek astronomer Hipparchus, quantified stellar brightness by grouping them into six orders of relative brightness -- from the brightest to the barely visible as seen with the naked-eye from a dark location. In what at first seems counterintuitive, the brighter stars have lower number while the dimmer stars have the higher numbers. Each magnitude has about a 2 ½ times difference in brightness. There are two stars (not counting the Sun) that have negative magnitudes: Sirius at -1.58 and Canopus at -0.86. Solar system objects with negative magnitudes include Jupiter at -2, Venus at -4, the full Moon at -12, and the Sun at -26.

The above magnitudes are known as APPARENT magnitudes and have size, luminosity, interstellar dust absorption, and distance factored in. ABSOLUTE magnitudes refer to the brightness of a star as seen from 10 parsecs (32.6 light years). The Absolute magnitude of the Sun is 5.

Conveniently placed in the late Spring Sky, is a celestial reference chart for comparing magnitudes
Map segment reproduced from MegaStar
Reference Star
Vega (Alpha Lyrae)
-1, 0, and 1st Mag. Combined
Deneb (Alpha Cygni)
Gamma Draconis*
Beta Dracois*
Xi Dracois*
Nu Draconis*
SAO 30538*

* These stars form the asterism "The Lozenge", and in some renditions of the constellation, form the head of the Dragon. SAO 30538 is the dragon's eye.

Hope to see everyone at the meeting,