THE OBSERVER The Astronomy Club of Tulsa’s Newsle er Published Since 1937
RON WOOD NETA APPLE JOHN LAND JACK EASTMAN BRAD YOUNG ANN BRUNN
FIND AThe BIT Astronomy OF HEAVEN Club IN ofOKLAHOMA Tulsa Prepares to Mark its 75th Year in a few Months!
www.astrotulsa.com All Rights Reserved Copyright 2011 Astronomy Club of Tulsa. NOVEMBER 2011
EDITORS NOTES THE COVER About This Issue:
Few things will no longer appear every month. One will be Actomart as this is a great sec on we just are not selling enough to keep it up every month. It will show back up as we have items our members would like to sell. The other will be The Toy Box and this does not appear every month because a cer n degree of research goes into this so we don’t just list items because they are new. Speaking of new we have added one new sec on this month , Beginners Challenge and we just have wait and see what response it has. I will con‐ nue to try new things and always welcome and credit sugges ons. Star ng next month we will be adding NASA’s Spaceplace as a feature, but more about that next month.
ASTRONOMER OF THE MONTH To Submit to the Observer: This month we go about 2,700 years forward and honor Carl Sagan. This should have been a easy Email your ar cle or content with pictures to jer‐ one for many of you who have read his books and [email protected] please put newsle er in seen the acclaimed Cosmos TV Mini‐Series. Carl is the subject or it might not show up. arguably one of the top 5 most famous. I am sure he has been seen by billions and billions. Ok, that was bad. NEW MEMBER CORNER Carl Sagan (1934‐1996, American) could be called 'the astronomer of the people'. He popularized the Here we go, September and October. Welcome science of astronomy with the general public, and All! revolu onized science fic on by believing that we Lee Bickle, Darrell Henk, Mandy Nothnagel, are not alone in the universe. He championed the Robbin Jones, Jon Ruyle, Andrew Foreman, search for extraterrestrial intelligence, which con‐ Mark Foreman, Ed Hinckley, Pa y Jeter and nues today with a number of missions to Mars to Jody Ray search for signs of life on that planet. 1 1 THE OBSERVER THE OBSERVER IS EDITED & PUBLISHED BY: JERRY MULLENNIX CONTENTS
3 Guest Speaker and Elec ons
4 Astro Prez (Message From the Ann Brunn President)
5 As The Dome Turns Jerry Mullennix
6 Find A Bit of Heaven in Oklaho‐ Ron Wood ma
8 Measuring the Distance to the Neta Apple Center of the Milky Way Gal‐ axy
12 How Dark is Your Site? Brad Young
16 Beginners Challenge Jerry Mullennix
17 NASA News NASA
21 Part II of Jack Eastman Speaks Jack Eastman on his Telescopes 26 November Board Mee ng Tamara Green Minutes
THE OBSERVER 2
Note: All build‐ ing loca ons in Due to our club dinner we will not have a guest speaker this month but mark map below are your calendars for December 9th when Meteorologist George Flickeinger will prior to earth‐ be our next scheduled guest speaker. quakes and Friday December 9, 2011 at 7:00 PM subject to change.
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WHAT AM I GOING TO OBSERVE TONIGHT?
By: Jerry Mullennix
Some of you may have no ced the what is now known in astronomy as beginning of Space/Time approx. 14 new logo on the front cover marking a Standard Candle (used for meas‐ billion light years and we now sus‐ our clubs 75th year in existence. It is urements). He presented his find‐ pect this may be one of countless a lot to think about and though I am ings in 1925 to the American Astro‐ universe's, some of which the phys‐ not posi ve but I believe we are the nomical Society where he was ics we understand here will not ap‐ oldest club in the State of Oklahoma. quickly rebuked. ply there.
Our sister club over in OKC is proudly Our club would exist before anyone Now, all of the informa on I have celebra ng their 50th and we con‐ believed there could actually be provided about the way we per‐ gratulate them. However, we were something 2 million light years from ceived space was from a treasured drinking age when they got started. the Earth. book I have tled Wonder Book, it I guess you could say “we were as‐ was published in 1935 by Funk & tronomy before astronomy was The Milky Way and stellar universe Wagnalls Company. cool.” was believed to be roughly lens‐ shaped and about 3,000 to 30,000 Our club has a lot to be proud of Here are some facts when we start‐ or more light years in extent. and all of us are fortunate to share ed: Sky and Telescope was two (Current wisdom shows about in the history of this club. Lets different magazines, Sky being one 100,000 though x‐ray scopes are make this a great year in astronomy and Telescope the other. They would finding it may be much bigger, may‐ and discovery . Happy Birthday! not be Sky and Tel for 5 more years. be X2.) In this space occur nearly all the stars, nearly all the diffuse neb‐ All of the li le smudges you know as ulosity's, nearly all the planetary galaxy’s including Andromeda were nebulae, nearly all new stars, nearly known as nebula because nothing all clusters, nearly all the variable existed beyond the Milky Way. stars, etc., but not spiral nebulae. That’s right, almost everyone There were approx. 100,000 spiral thought the Milky Way was the en‐ nebulae who’s distance could not re Universe. known. This is because they did not believe the measurements they cal‐ Why I say almost, there was one culated for theses and assumed the young man, Edwin Hubble who standard candle was only accurate made observa ons with the Hooker to a fixed distance from Earth. Telescope in 1923 where he iden ‐ fied Cepheid Variables in several of We now know them as galaxy’s and these nebulae, including Androme‐ 100,000 doesn’t begin to count 1 da and Triangulum. Cepheid's are them. Their distances go back to the 5 THE OBSERVER Find a Bit of Heaven in Oklahoma
By Ron Wood BY: RON WOOD
A few years ago there was a story path of totality sweeping diagonally original material has been replaced about an amateur astronomer who across the US from Washington by minerals. A thumbnail‐sized slice received a picture postcard from a state to Florida, passing across Oke‐ sold on Ebay this spring for $16; or friend who was vaca oning in Eu‐ mah at about 4:30. Tulsa appears you can get a thin, square, 6X6 inch rope. The picture was an aerial to have been just within the north‐ slab for about $2000. view of the countryside, and the ern edge of the path. An equally important 17 kg meteor‐ recipient, studying the card, became Besides this eclipse, I was aware of ite fell near Lost City in northeastern convinced that it contained the very only two other leads to inves ‐ Oklahoma at 8:14 pm, Jan. 3, faint image of an unknown astro‐ gate: the Lake Murray and Lost City 1970. The importance of this mete‐ bleme‐‐‐an impact structure‐‐‐ meteorites. orite lies in the fact that its flight which, as it turned out, it did. Con‐ path was captured on film by sever‐ sequently, I cannot look at any such The Lake Murray meteorite was dis‐ al cameras of the Smithsonian Prai‐ image without compulsively exam‐ covered by J.C. Dodson in 1933 pro‐ jec ng from the side of a gully on rie Network, which had gone into ining it for signs of an astrobleme. pur‐ his farm near Lake Murray, but it opera on in 1960 for just this The word comes from the Greek for pose. These photographs made it was not excavated un l 1952 when "star scar." It is synonymous with possible to calculate the orbit is usually used Dodson guided a Mr. Gra am, di‐ impact structure and around the sun, the trajectory when referring to a highly eroded rector of the Tucker Tower muse‐ through the atmosphere, and the crater. um, to the site. Gra am, recogniz‐ ing the importance of the find, im‐ likely point of impact. This had only For example, whenever I go to the mediately called the Ins tute of Me‐ been done once before, in the case Na onal Weather Service website teori cs at the Univ. of New Mexico of the Pribram meteorite fall in to check the radar, my eye gravi‐ which dispatched a recovery team Czechoslovakia in 1959. tates to a large, faint, circular fea‐ at once. It proved to be the largest Gunther Schwarz, manager of the ture on the map just to the north‐ meteorite ever found in Oklahoma, network sta oned in Nebraska, If east of Ardmore. Check it out. weighing over 600 pounds, and the heard of the fall on the 10 o'clock you don't see it right away try using largest granular hexahedrite in the news and called network headquar‐ your averted imagina on. It is world. ters in Cambridge, MA, se ng in about 15 miles in diameter and is mo on a prearranged plan. Eight‐ bisected by the Pontotoc/Johnston It was embedded in sand‐ county line. So, fishing for a topic stone da ng from the Cre‐ for this ar cle, I decided to do a sur‐ taceous period, sugges ng vey of astroevents of the Oklahoma that it landed in a near‐ region. shore, shallow sea as the‐ se beds were being depos‐ Over the years I heard my dad tell of ited about 110 million accidently seeing a total solar years ago. This makes it eclipse near Okemah in 1918 when the oldest intact meteorite he was six years old. A brief search on earth, though older confirmed that such an eclipse did "fossil meteorites" have LAKE MURRAY METEROITE in fact occur on June 8th, with the been found in which the THE OBSERVER 6 een hours a er the fall an Air Force sediment it was not even recog‐ crater 50 feet in diameter, making it plane flew at 60,000 . from Okla‐ nized as an astrobleme un l one of the smallest in the world. Its homa City to Atlanta, Georgia, and 1991. It is 8 miles in diameter and age is es mated to be less than back, taking air samples. is dated to 470 million years 1000 years. Over 15,000 pounds of ago. The subterranean crater is pallasite meteorites have been re‐ Driving from Nebraska, Schwarz beau fully depicted on the Ames covered from the site. was not able to reach Lost City un l Museum website by graphics devel‐ Jan. 9th due to icy roads and 8 inch‐ In Missouri, Weaubleau‐Osceola is oped from seismic data. Ames is es of new snow. He drove from the fourth largest crater in the Unit‐ Lost City toward the impact area one of the most intensively studied ed States. It is believed to have intending to tell the local residents craters in the world and one of six been caused by a 1200 . meteor‐ what to look for, but just outside petroleum‐ producing craters in the oid between 310 and 340 million town he found the meteorite lying US. years ago. Associated conglomer‐ in the road 800 meters from the I did discover another very inter‐ ate rocks found in the area are predicted point of impact. es ng site in the Oklahoma panhan‐ nearly perfectly round and are re‐ dle on Bull ferred to locally as "Missouri rock Creek in Bea‐ balls." ver County. In Also in Missouri, Crooked Creek 2007 a 26‐ Crater is 7 km in diameter with an member team age es mated at 80 million years. from 16 ins ‐ Decaturville Crater in Missouri is 6 tu ons theo‐ km in diameter and is less than 300 rized that a million years old. cosmic impact over North In Texas, Sierra Madera Crater is 13 LOST CITY METEORITE America, pos‐ km in diameter and is es mated to sibly similar to be less than 100 million years the 1908 cometary airburst over old. A central peak rises 793 feet A very great deal of important infor‐ Tunguska, set off a 1,300‐year‐long above the surrounding desert. ma on was derived from the Lost Younger City meteorite, making it possible to cold spell known as the Also in Texas Odessa Meteor Crater Dryas, fragmen ng the prehistoric more accurately determine such is the largest of several craters in Clovis culture and leading to the things as the cosmic ray flux in the the area formed by the impact of ex nc on of 35 species of mam‐ inner solar system and the density thousands of octahedrites. Over mals, including mammoths. and composi on of subsequent me‐ 1500 meteorites have been recov‐ teors. You can buy a one‐inch, 1.5 Team member Douglas Kenne re‐ ered from the area, the largest of gm slice of Lost City from Mile High ported finding nanometer‐sized dia‐ which weighed approximately 300 Meteorites for $500. Meteors and monds concentrated in the relevant pounds. The crater is 550 feet in eclipses are all well and good, but sedimentary layer at all six wide‐ diameter and is es mated to be less my fever ran high for making an spread sites in the study including than 50,000 years old. Due to ero‐ original discovery of an "Ardmore Bull Creek. The theory and Ken‐ sion the crater is currently 15 feet Astrobleme." I did find a very im‐ ne 's findings are both the subjects deep at its lowest point. pressive astrobleme, but someone of a heated but very interes ng de‐ Given the density of astroblemes in else found it first, and it is almost bate. the region I have high hopes that two hundred miles from I couldn't find any men on of other some future search may uncover is in northwestern Ok‐ Ardmore. It impact sites in Oklahoma though the Ardmore‐‐or make that, the Ron lahoma near the small town of there are a surprising number near‐ Wood Astrobleme. Ames in Major County. by in surrounding states. In Kansas, Since it is buried under 9000 . of Haviland Crater is an oval‐shaped
7 THE OBSERVER
DAY
THE
OF
PICTURE
ASTRONOMY
CREDIT: By Neta Apple PHOTO
Introduc on ing inves ga ons to determine this of the Galaxy by using variable stars, distance, R , seem to indicate that known as Cepheids. Cepheids had For centuries mankind believed the 0 the IAU may soon need to revise its recently been discovered to have a Earth was the center of the Uni‐ recommenda on again. precise rela onship between their verse. A er it was proven that the period of variability and their bright‐ Earth orbits the Sun, it was thought Why is the value of R important? 0 ness, or luminosity. He logically as‐ that the Sun was the center of the Simply put R can be used as a meter 0 sumed that Cepheids in the distant Universe. It was only in 1920, less s ck for other distance measure‐ globular clusters would follow this than 100 years ago, that the young ments. Before exploring this more same rela onship and that he could astronomer Harlow Shapley first fully, it is necessary to review some use these Cepheids as “standard used the distribu on and distances history and examine some of the candles” by use of which he could to globular clusters to show that the various methods that have so far determine the distances to the glob‐ Sun lies at a distance from the cen‐ been used to determine R0 and the ter of the Milky Way Galaxy, not at accuracy of the results. ulars, then use this informa on to determine the distance to the point its center. Using this informa on, he History calculated the diameter of the Gal‐ about which they were distributed. axy to be about 300,000 light years, While working at the Mt. Wilson Ob‐ with the Sun being about 13 kpc servatory just a er the turn of the th Assuming that the Cepheids he ob‐ (kiloparsecs; 1 kpc = 3261.6 light 20 century, Harlow Shapley noted that the 69 globular clusters known served in the globular clusters had years) from its center, farther than the same period‐luminosity rela on‐ the current accepted figure. at the me were arranged in a huge sphere which was centered on a ship as those located nearer, he In 1985 the Interna onal Astronomi‐ point located several kiloparsecs measured the apparent brightness cal Union (IAU) recommended the away from Earth. He reasoned that and length of period of the globular use of 8.5 kpc, (about 28,000 light due to the ac on of gravita onal cluster Cepheids and compared ‐ years), rather than the previous val forces this point should be the cen‐ them to those located nearer the ue of 10 kpc (Po asch 1990) for the how ter of the Milky Way. Sun. He could then calculate by distance from the Sun to the center much each of the globular variable of the Galaxy. Results from con nu‐ Shapley set out to determine the size stars was dimmed, and using the in‐
THE OBSERVER 8 Measuring The Distance To the Center of the Milky Way Galaxy
verse square law, which states that the measurement is made in one A*, the central black hole of the Gal‐ the distance to a bright object di‐ single step rather than relying on axy, using the ESO Very Large Tele‐ minishes with distance by the secondary calibra ons and mul ple scope (VLT) located in Chile. This square of the object’s distance from steps. Direct measurements using method involves determina on of the observer, determine how far stellar parallax are impossible due to the proper mo ons and line‐of‐sight away it was. By measuring the dis‐ the very small angles of parallax in‐ velocity of the star, the same meth‐ tance to the central point of the volved at such distances so other od used for orbi ng binaries, and sphere of globulars he in effect methods must be employed. Two the use of Kepler’s third law to ob‐ measured the distance to the center examples of primary methods are tain R0. One cannot argue with the of the Galaxy. distance measurements to water directness of the method‐ it does Shapley’s value of about 13 kpc, masers and to stars very near the not require allowances for ex nc on (Reid 1993) is nearly twice modern galac c center. and has been proven reliable by use in other loca ons. It seems that this values. At that me Shapley had no Reid, et al (1988) used water masers method should be one of the most way of knowing that his sampling to measure the distance to the cen‐ accurate and precise. contained two types of Cepheids. ter of the Galaxy. Interstellar ma‐ Now known as Popula on I and Pop‐ sers occur in molecular clouds proxi‐ As previously noted, Shapley’s de‐ ula on II based on their metallicity, mal to massive newly formed stars. termina on of the distance to the each group has a different period‐ Traces of water vapor are associated galac c center used “standard can‐ luminosity rela onship. He had no with these stars. Water molecules dles,” thus it fits into the class of way to know that the variable stars can become “excited” in these loca‐ secondary methods. These methods he used in the globular clusters were ons and produce masing rely on the idea that certain types of older, less metallic and thus dimmer “spots” (Reid, 1993). The mo on of distant objects are the same and than expected. This combined with these spots can be measured using have the same luminosity, or bright‐ ex nc on, dimming of distant stars Very Long Baseline Interferometry ness, as similar objects located near‐ due to intervening dust, produced (VLBI) to measure Doppler shi s and by. This has become more accurate this erroneous result (Reid, 1993). angular mo ons indica ng various as more is now known about the ob‐ S ll, this was a wonderful achieve‐ velocity components to within a few jects chosen for use as standard can‐ ment since it forced astronomers to km/sec in a technique which has dles and with the ability to observe consider that the Sun is not at the been called “expanding cluster par‐ the objects in wavelengths other center, and that the Galaxy might be allax.” Using such data from a water than visible light , (e.g. radio, IR, and very large. source in the area designated Sgr X‐rays), that are not highly affected B2, which lies very close to the cen‐ dust. Selec on of Modern Determina ons of R by intervening 0 ter of the galaxy, Reid, et al (1988) standard candles about which a Currently astronomers use several determined the distance to Sgr B2 to great deal is understood is vital to methods to measure R0, all of which be 7.1 ± 1.5 kpc by comparison of accuracy. A demonstra on of this fall into three basic categories: pri‐ angular and line‐of‐sight veloci es. concept is evident in repe on of mary methods which are measured Shapley’s work by Racine and Harris directly without use of a “standard Eisenhauer, et al, (2003) claim to have made the most accurate prima‐ (1989) who obtained a value of R0= candle;” secondary methods use 7.5± 0.9 kpc. “standard candles” such as the vari‐ ry measurement of R0. They also able stars used by Shapley; and indi‐ claim their value of 7.94 ± 0.42 kpc Other modern studies involving the rect methods which combine theo‐ has few uncertain es of astrophysi‐ use of the Cepheids as standard can‐ = re cal modeling of the Galaxy with cal origin, and is the first primary dles have resulted in results of R0 7.8± 0.7 kpc (Caldwell & Coulson several observa ons (Reid, 1989 and distance determina on with an un‐ 1987). Use of RR Lyrae stars by Car‐ 1993). certainty of less than 5%. This value was obtained from astrometric and ney et al (1995) yielded a value of Primary methods of measurement near infrared observa ons of the 7.8± 0.4 kpc. of R should be more accurate since 0 star S2 which orbits very near Sgr
9 THE OBSERVER Measuring The Distance To the Center of the Milky Way Galaxy
for these methods range from 7.6 kpc to 10.4 kpc with a variety of es‐ mated errors (Reid 1989, 1993) which seem largely dependent upon the reliability and directness of the method. Each of these methods has a great deal of uncertainty and thus results do not seem as accurate or precise as those obtained by more direct methods.
Significance of R0 Since the distances to far‐away ob‐ jects in the Universe are determined by the use of Galac c standards, the value of R0 has an aspect even more important than determina on of the size of the Galaxy. The Hubble constant and R0 are somewhat in‐ terrelated and thus it may be possi‐ ble to use the Galaxy as a sort of intergalac c meter s ck to measure distances to other spiral galaxies in the future (Reid 1993).
Figure 1 Location of red clump stars on the Hipparchos color-magnitude A change in the value of R0 leads to changes in many areas of astrophys‐ diagram which plots color of stars compared to absolute ics, e.g. kinema c distances, mass brightness. From http://cfa-www.harvard.edu/~kstanek/RedClump/. determina ons of the Galaxy and the Galac c center (Carney et al Another standard candle method (Baade’s Window is a “hole” in the 1995), which are fundamental to uses red clump stars. Red clump dust that shrouds the center of the many of the theories and models of stars are giant, bright, metal rich Galaxy through which stars near the the Galaxy and the Universe. Par c‐ stars located just above the turn off Galac c center may be examined ularly intriguing is the idea that an point on the color‐magnitude dia‐ (Nemiroff & Bonnell 2002),) This improved determina on of R0 gram (see Figure 1) that have fin‐ method gives the distance to the would enable accurate recalibra on ished fusing the hydrogen in their galac c center in one step which of standard candles such as globular clusters, O and B type stars, red cores and progressed off the main yielded R0 = 8.4 ± 0.4kpc. to Paczsynski clump stars, planetary nebulae, and sequence. According There are a great variety of indirect and Stanek (1998) red clump stars Cepheid, RR Lyrae and Mira type objects and method combina ons are very common, and very well un‐ variable stars with greater precision that can lead to a value of R0. Some for use in determining distances to derstood making them good candi‐ examples include the use of rota on dates for use as standard candles. nearby galaxies observed to contain models of the Galaxy (Caldwell & these same types of objects. Thus Trigonometric parallaxes of ~ 600 Coulson 1987) in conjunc on with nearby red clump stars from Hippar‐ the distances to nearby galaxies various types of stars including plan‐ would change. chos and their absolute magnitudes etary nebulae, Cepheid variables, were compared with apparent mag‐ bright type O and B stars, IR stars Determina on of the absolute mag‐ nitudes of red clump stars in Baa‐ and Sgr A* itself. Values obtained nitude of RR Lyrae stars would bear de’s Window measured by OGLE. THE OBSERVER 10 Measuring The Distance To the Center of the Milky Way Galaxy
heavily on the determina on of curate and precise determina on their metallicity and ages. This in‐ of R0 which will enable more accu‐ forma on is in turn used to con‐ rate determina on of distances strain the age of the Universe and inside and outside the Galaxy. the Hubble constant. Conclusions References can Accurate determina ons of R0 Caldwell, J. A. R. & Coulson, I. M., be used to calibrate standard can‐ 1987, AJ, 93, 1090. dles for use in measuring distances to other galaxies, in development Carney, B., Terndrup, D., Suntzeff, of models of the Galaxy and in de‐ N. & Walker, A., 1995, AJ, 110, termining the size and age of the 1674. Universe. Eisenhauer, F., Schodel, R., Genzel, Astronomers use a variety of meth‐ R., O , T., Tecza, M., Abuter, R., ods to determine the Galactocen‐ Eckart, A. & Alexander, T., 2003, ApJ tric distance, some of which are 597, L121. more direct and thus more accu‐ Nemeroff, R. & Bonnell, J., 2002, rate than others which require the Astronomy Picture of the Day use of standard candles, mul ple h p://apod.nasa.gov/apod/ steps or models in making the de‐ ap021223.html termina on. Paczynski, B., & Stanek, K., 1998, Values for R0 range from 7.1 kpc to ApJ, 49, L219. 10.4 kpc, with varying amounts of error inherent to each determina‐ Po asch, S.R., 1990, A&A, 236, 231. on. The IAU currently recom‐ Racine, R. & Harris, W., 1989, ApJ, mends use of R0 = 8.5 kpc which is 98, 1609. greater than most of the values Reid, M. J., Schneps, M. H., Moran, reported here. Thus it would seem J. M. & Gwinn, C.R., 1988, ApJ, 330, that in the near future the IAU may 809. need to re‐examine this value and recommend a revision. Some re‐ Reid, M. J., 1993, ARA&A, 31, 345. searchers are already beginning to Reid, M.J., 1989, AUS, 136, 37. use 8.0 kpc.
Comparing values of R0 since that first measurement made by Shap‐ ley nearly a century ago, one might think we lived in a shrinking Gal‐ axy! At this me the value of R0 is just over half of Shapley’s value. The Galaxy has not shrunk, rather the knowledge of how to accurate‐ ly measure the Galaxy, and thus the Universe, has instead grown. It would appear that astronomers are now zeroing in on a highly ac‐
11 THE OBSERVER By: John Brad Land Young & Jerry Mullennix
Please Note, This was wri en prior to this is something we should pursue. This site may replace or supplement Ann’s President Message and some the current site at Mounds. For a lot of reasons Hulah lake of my por on of this message does might not make a good site for us SCREENING COMMITTEE FOR‐ not apply now. but we would like to invite the en re MATION board to join us in viewing from this A commi ee of 3‐5 persons would where we could have an extend‐ As it is said in the Godfather ; “I am site be formed to screen possible sites, ed discussion , for that ma er we going to make them an offer they select a primary and one alternate, would like to invite anyone interest‐ and report to the Board their find‐ cannot refuse.” Last month I men‐ ed in a dark sky site to load their tel‐ ings by March 31, 2012. This com‐ oned that our club needed to accel‐ mi ee would be headed by a Com‐ escope and come along. We could erate the topic of procuring a dark mi ee Chairman, who would be re‐ sky site for the Astronomy Club of call it “ACT’s Dark Sky Search Star sponsible for submi ng the selec‐ Tulsa and that our Board should Party.” As our board has just started on, working with the other mem‐ Ann has not even had a chance bers. All members of this commi ee move it higher on the priority list. A and to hold a mee ng yet so this is just shall be Astronomy Club of Tulsa few days a er the newsle er hit the members in good standing. Volun‐ an idea—besides winter is taking a stands Brad Young , a long me club teers would be called for in the next member ,posted a detailed proposal foothold and viewing opportuni es Club Newsle er, general email, ob‐ for the Boards considera on on this are going to be narrowed for a few serving night, and/or indoor topic. I have reprinted the post fol‐ months. One thing we all must un‐ mee ng. The selected volunteers this shall elect the Commi ee Chairman. lowing my note. derstand if this is to succeed is will not be a quick process, we must The Commi ee would establish a Work Plan including mee ng sched‐ I had a long talk with Brad, when we take our me and do it right. meet at Hulah Lake last Friday night, ule and loca on immediately a er Jerry Mullennix the elec on of the Chairman. about his post. I quickly realized that Brad well understood all of the obsta‐ COMMITTEE DELIVERABLES cles' that faced us such as money, Post: By Brad Young A formal proposal would be devel‐ availability, drive me, and the big‐ Towards a New Observing Site oped by the Screening Commi ee. gest, ge ng the club to agree. A er The proposal would address the fol‐ our Discussion both Brad and I along For Considera on by the ACT Board. lowing issues: with Steve Chapman decided we October 25,2011 Sky Darkness (Bortle Scale or Light would be willing to volunteer our Meter Measurements) and Light me as part of the original screening The me has come to iden fy, de‐ sign, and procure a new observing Domes (if any) commi ee to get this started, (see site for the Astronomy Club of Tulsa. below) should our board decide that Es mate of Useful Life based on re‐ THE OBSERVER 12 How Dark Is Your Site?
cent construc on in area A er receipt of the Proposal, the A er receipt of the Proposal, the Board would have 30 days to accept Board would have 30 days to ac‐ Weather and Environmental Con‐ or comment on the Proposal. Com‐ cept or comment on the Proposal. cerns: mi ee would have 30 days to ad‐ Commi ee would have 30 days to dress the comments, at which me address the comments, at which Wind, Dew, Noise, Safety, Public the Proposal would be set to a vote me the Proposal would be set to a Use / Traffic by the General Membership of the vote by the General Membership Club. This vote would be a special of the Club. This vote would be a Seasonal Issues elec on held during a regular Club special elec on held during a regu‐ Incidental Light Sources (light Mee ng or announced at least 30 lar Club Mee ng or announced at poles, etc.) days before the vote is cast. least 30 days before the vote is cast. Suitability for: If the Board or Commi ee finds BY: BRAD YOUNG there is not a tenable site during If the Board or Commi ee finds Casual Observer the review period, the party re‐ there is not a tenable site during sponsible for determining the Pro‐ the review period, the party re‐ Visitors / Public Events posal is untenable shall make a sponsible for determining the Pro‐ wri en report available to all Gen‐ posal is untenable shall make a Overnight Observers eral Members within 30 days of the wri en report available to all Gen‐ decision, describing in detail the eral Members within 30 days of the Future Mul day use (e.g. reasons why the Proposal why the decision, describing in detail the Star Party) General Membership will not be reasons why the Proposal why the Accommoda ons: Onsite or Nearby presented with the Proposal. This General Membership will not be report shall be presented at a regu‐ presented with the Proposal. This U li es Available or Availability lar Club Mee ng and a vote held to report shall be presented at a regu‐ accept the conclusion or restart the lar Club Mee ng and a vote held to Distance / Route Drivability from screening process. accept the conclusion or restart the Downtown Tulsa screening process. SCREENING COMMITTEE DETAILS Procurement Plan including:
Lease or Purchase Ex‐ pense
Recurring Costs (Taxes / Insurance / U li es / etc.)
Improvements (Conceptual Plan and Budget)
Schedule
Funding Source
Transi onal or Supplemental Plan with Mounds Site.
BOARD REVIEW AND ACTION 13 THE OBSERVER Dark Sky Site Report Form How Dark Is Your Site?
Observers Name___Brad Young______Date of Observa on______10/28/2011______Site__Hulah Lake (Boat Landing)______
Loca on of Observer La tude__ 36.8797. ______Longitude___‐95.9892 ______(west is nega ve) Eleva on____797 ______Instrument Used (check one) _____Unaided Eye Draw or sketch light domes at the site.
Sky Darkness (Bortle Scale or Light Meter Measurements) and Light Domes:
See drawing above and map on next page.
Es mate of Useful Life based on recent construc on in area: Not addressed
Weather and Environmental Concerns:
Wind – could be a problem with no trees and lakeside site
Dew – dew reported by others; lake side site
Noise – boats, cars (occasional)
Safety – rangers; state park; no shelter
Public Use / Traffic – busy in summer, light traffic
Seasonal Issues – cold wind from lake in winter
Incidental Light Sources (light poles, etc.) occasional boats, small cluster of lights on opposite shore
Suitability for:
Casual Observer – 1‐2 hour drive back to Tulsa
Visitors / Public Events – probably not useful
Overnight Observers – need to establish shelter or use RVs
Future Mul day use (e.g. Star Party) – public land; not useful for private event
Accommoda ons Onsite or Nearby – RV hookups, campsites within a mile (fee)
U li es Available or Availability – not at this site, at campground
Distance / Route Drivability from Downtown Tulsa 1.5 hours, all four lane or primary two lane highways and paved access
THE OBSERVER 14 How Dark Is Your Site?
Procurement Plan including:
Lease or Purchase Expense – not an op on at this site (see note below)
Recurring Costs (Taxes / Insurance / U li es / etc.) N/A
Improvements (Conceptual Plan and Budget) N/A
Schedule N/A
Funding Source N/A
Transi onal or Supplemental Plan with Mounds Site: See note below.
General consensus among a endees was that this par cular site is useful only for short term, casual use. However, areas to north and west should be further scouted for land available for lease or purchase. The white cross below shows the loca on of the Hulah Lake Boat Ramp, in an area classified as:
Sky Brightness Ar ficial / Natural Bortle Scale mags / sq arcsec Descrip on (Descrip ons are approximate. Your sky may vary.) Sky Brightness approx V Band
21.89 to Low light domes (10 to 15 degrees) on horizon. M33 easy with averted vision. 3 M15 is naked eye. Milky way shows bulge into Ophiuchus. Limi ng magnitude 6.6 0.11 to 0.33 21.69 to 7.0.
15 THE OBSERVER Beginners Challenge DECEMBER, 2011 ConstellaƟon of the Month Andromeda M‐31, M‐32 and M‐110 or The Great Andromeda Galaxy Group. All three can be seen in photo to the Right with M‐110 being the bright spot at the bo om and M‐32 being the bright spot at the top. NGC 891 is a fine edge‐on spiral galaxy, missed by Messier. It was discov‐ ered by William Herchel Andromeda The Chained Maiden: Andromeda is visible from August to January in the northern hemisphere. She on October 6, 1784. At lies between Pisces and Cassiopeia, with her head at the upper le corner of the Great Square of Pegassus, and Mag 9.96 It is a rela vely her feet near Perseus. The Star Sirah marks her head, Mirach marks her hips, and Almach represents her chained easy object for tele‐ scopes.
Mirach’s Ghost NGC‐404 Planet of the Month Jupiter is the largest planet in our solar system, and by far the most massive. It contains over twice as much ma er as all of a nice Ellip cal Galaxy Jupiter that appears to hide be‐ the other planets combined. Jupiter is a very different planet hind the bright star from the Earth, or any of the other inner planets. It is composed Mirach. Mag 10.25 mostly of liquid and gaseous hydrogen, and has not solid sur‐ face. For this reason, Jupiter is the first of the “gas giant” plan‐ ets.
Jupiter has 63 known moons these range in size of 1/2 mile Astronomy Club of Tulsa across to Ganymede the largest moon in our solar system so large in fact it is bigger than Mercury or Pluto. Jupiter’s 4 main moons are Io, Europa, Callisto and Ganymede all four can be astrotulsa.com seen with binoculars. PASADENA, Calif. ‐‐ NASA’s Deep (324,600 kilometers) as measured ject Program Office for NASA's Sci‐ Space Network antenna in Gold‐ from the center of Earth, or about ence Mission Directorate in Wash‐ stone, Calif. has captured new ra‐ 0.85 mes the distance from the ington. dar images of Asteroid 2005 YU55 moon to Earth. The gravita onal passing close to Earth. influence of the asteroid will have The new radar images are online no detectable effect on Earth, in‐ at: The asteroid safely will safely fly cluding des and tectonic plates. h p://www.nasa.gov/ past our planet slightly closer than Although the asteroid is in an orbit mission_pages/asteroids/ the moon's orbit on Nov. 8. The last that regularly brings it to the vicini‐ mul media/yu55‐20111107.html . me a space rock this large came as ty of Earth, Venus and Mars, the close to Earth was in 1976, alt‐ 2011 encounter with Earth is the For more informa on about aster‐ hough astronomers did not know closest it has come for at least the oids and near‐Earth objects, visit: about the flyby at the me. The last 200 years. h p://www.jpl.nasa.gov/ next known approach of an aster‐ asteroidwatch . oid this size will be in 2028. NASA detects, tracks and character‐ izes asteroids and comets passing The image was taken on Nov. 7 at close to Earth using both ground‐ 11:45 a.m. PST (2:45 p.m. EST/1945 and space‐based telescopes. The UTC), when the asteroid was ap‐ Near‐Earth Object Observa ons proximately 860,000 miles (1.38 Program at NASA’s Jet Propulsion million kilometers) away from Laboratory in Pasadena, Calif., Earth. Tracking of the aircra carri‐ commonly called "Spaceguard," er‐sized asteroid began at Gold‐ discovers these objects, character‐ stone at 9:30 a.m. PDT on Nov. 4 izes some of them, and plots their with the 230‐foot‐wide (70‐meter) orbits to determine if any could be antenna and lasted about two poten ally hazardous to our plan‐ hours, with an addi onal four et. JPL manages the Near‐Earth Ob‐ hours of tracking planned each day from Nov. 6 ‐ 10.
Radar observa ons from the Areci‐ bo Planetary Radar Facility in Puer‐ to Rico will begin Nov. 8, the same day the asteroid will make its clos‐ est approach to Earth at 3:28 p.m. PST (6:28 p.m. EST/1128 UTC).
The trajectory of asteroid 2005 YU55 is well understood. At the point of closest approach, it will be no closer than 201,700 miles
17 THE OBSERVER News release: 2011‐337 Nov. 2, end of a period of hundreds of mil‐ hosted warm, wet condi ons. If 2011 lions of years during which warm those condi ons existed on the sur‐ water interacted with subsurface face for a long era, the planet would NASA Study of Clays Suggests Wa‐ rocks. This has implica ons about have needed a much thicker atmos‐ tery Mars Underground whether life existed on Mars and phere than it has now to keep the how the Mar an atmosphere has water from evapora ng or freezing. PASADENA, Calif. ‐‐ A new NASA changed. Researchers have sought evidence of study suggests if life ever existed on processes that could cause a thick Mars, the longest las ng habitats "The types of clay minerals that atmosphere to be lost over me. were most likely below the Red formed in the shallow subsurface are Planet's surface. all over Mars," said John Mustard, This new study supports an alterna‐ professor at Brown University in ve hypothesis that persistent warm A new interpreta on of years of Providence, R.I. Mustard is a co‐ water was confined to the subsur‐ mineral‐mapping data, from more author of the study in the journal face and many erosional features than 350 sites on Mars examined by Nature. "The types that formed on were carved during brief periods European and NASA orbiters, sug‐ the surface are found at very limited when liquid water was stable at the gests Mar an environments with loca ons and are quite rare." surface. abundant liquid water on the surface existed only during short episodes. Discovery of clay minerals on Mars "If surface habitats were short‐term,
These episodes occurred toward the in 2005 indicated the planet once that doesn't mean we should be Mullennix
Mullennix
Jerry
Jerry
By:
By:
Photo Photo
Mullennix
Mullennix
Jerry
Jerry
By:
By:
Photo Photo Impact cratering and erosion combine to reveal the composi on of the Mar an underground by exposing materials from the subsur‐ face. Image credit: NASA/JPL‐Caltech/JHUAPL THE OBSERVER 18 glum about prospects for life on most terrains on Mars with iron and Mars Science Laboratory mission. Mars, but it says something about magnesium clays. In contrast, sur‐ Launching this year, the mission’s what type of environment we might face environments with higher ra ‐ Curiosity rover will land and inves ‐ want to look in," said the report's os of water to rock can alter rocks gate layers that contain clay and lead author, Bethany Ehlmann, as‐ further. Soluble elements are car‐ sulfate minerals. sistant professor at the California ried off by water, and different alu‐ Ins tute of Technology, Pasadena, minum‐rich clays form. NASA's Mars Atmosphere and Vola‐ and scien st at NASA's Jet Propul‐ le Evolu on Mission, or MAVEN, in sion Laboratory, also in Pasadena. Another clue is detec on of a min‐ development for a 2013 launch, "The most stable Mars habitats eral called prehnite. It forms at tem‐ may provide evidence for or against over long dura ons appear to have peratures above about 400 degrees this new interpreta on of the Red been in the subsurface. On Earth, Fahrenheit (about 200 degrees Cel‐ Planet's environmental history. The underground geothermal environ‐ sius). These temperatures are typi‐ report predicts MAVEN findings ments have ac ve ecosystems." cal of underground hydrothermal consistent with the atmosphere not environments rather than surface having been thick enough to pro‐ The discovery of clay minerals by waters. vide warm, wet surface condi ons the OMEGA spectrometer on the for a prolonged period. European Space Agency's Mars Ex‐ "Our interpreta on is a shi from press orbiter added to earlier evi‐ thinking that the warm, wet envi‐ JPL, a division of Caltech, manages dence of liquid Mar an water. Clays ronment was mostly at the surface the Mars Reconnaissance Orbiter form from the interac on of water to thinking it was mostly in the sub‐ for NASA's Science Mission Direc‐ with rock. Different types of clay surface, with limited excep ons," torate in Washington. APL provided minerals result from different types said Sco Murchie of Johns Hopkins and operates CRISM. For more in‐ of wet condi ons. University Applied Physics Labora‐ forma on about the Mars Recon‐ tory in Laurel, Md., a co‐author of naissance Orbiter, visit: h p:// During the past five years, research‐ the report and principal inves gator www.nasa.gov/mro and h p:// ers used OMEGA and NASA's Com‐ for CRISM. mars.jpl.nasa.gov/mro . pact Reconnaissance Imaging Spec‐ trometer, or CRISM, instrument on One of the excep ons may be Gale the Mars Reconnaissance Orbiter to Crater, the site targeted by NASA's iden fy clay minerals at thousands of loca‐ ons on Mars. Clay minerals that form where the ra o of water interac ng with rock is small generally retain the same chemical ele‐ ments as those found in the original volcan‐ ic rocks later altered by the water.
The study interprets this to be the case for
A Russian‐built, neutron‐shoo ng instrument on the Curiosity rover of NASA's Mars Science Laboratory mission will check for water‐bearing minerals in the ground beneath the rover. Image Credit: NASA/JPL‐Caltech
19 THE OBSERVER THE ASTRONOMY CLUB OF TULSA
FRONT ROW SEATS TO THE BATTLES OF WINTER AT AN ASTRONOMY CLUB OF TULSA STAR PARTY! OPEN TO THE PUBLIC.
For More Informa on Please Visit www.astrotulsa.com
19 THE OBSERVER By: Jack Eastman
look through early on, and finally Wyld, (pp 581‐‐). Then there was gained the use of on a nearly un‐ the problem of glass. Mirror blanks limited basis. There was an iden ‐ were plen ful and cheap, op cal cal 6" at the student's observato‐ glass wasn't. Today none of it is. ry at UCLA. Remember, from Part Cheap, that is! 1, my driving my parents ba y about a bigger telescope, I kept Somewhere along the line, I think I howling about Unitron: "Look a was just finishing up at UCLA, we 4"! and on an equatorial to were roo ng around at the venera‐ boot!!" Never mind the equiva‐ ble old C&H Sales in Pasadena when In the con nuing saga of one person's lent price, in today's dollars, of I came across what appeared to be a empts at the perfect telescope, I offer the something like $8,000! This all 4" lens blanks. Fat biconvex and following. Having gone on at length about passed, sort of, with the comple‐ deep plano‐concave pressings, the Newtonian in part 1, I now go to the Re‐ on of the 12.5", but, s ll, a 4‐ or which if made into lenses, would fractor. This story is a bit circuitous, as this so inch refractor would have been have been very short, maybe f/3 or telescope evolved over several incarna ons, nice. f/3.5. I don't recall if the index and star ng with a small lens, then to a Schmidt dispersion numbers were on these Cass, from which the mount was born, finally I had the delusion of trying to or if we just assumed they'd be to the acquisi on of a really fine 5‐inch lens, make a lens. This seemed, at the "ordinary" crown and flint. I bought and the fabrica on of the 5‐inch tube assem‐ me, out of reach. For one thing a couple of sets of these things, for bly. This whole process was spread over the math involved looked formi‐ a quarter each, and thought serious‐ about 10 years, as opposed to the 6 or 7 dable. Maybe a er I had algebra... ly about making the long sought months for the 12.5‐inch. That came and went, maybe a er 4" lens. Using the formulas for Trig... No, how about Calculus... color correc on and assuming the I had always wanted a refractor of By the me I bit the bullet, I discov‐ proper es of these chunks of glass I some size. I s ll had, and have to ered all the high powered math set about to regrind the curves to this day, the 60mm Polarex, and a wasn't needed. A li le algebra may‐ make an f/15. It turned out these couple of other 60mm 'scopes, but be, and a whole lot of arithme c. things weren't 4" but something they are 60mm. A real refractor is a The gory details of the design pro‐ less, leading to a 3.6" aperture. I 4" or more. As I said earlier, except cess really is beyond the scope of thought if I make the crown equi‐ for the Kno s telescope, a Newtoni‐ this discussion, however, these de‐ convex, and match the concave side an, I was raised on refractors. There sign methods are described in Ama‐ of the flint, I could test the concave was the 12" Zeiss at the Griffith Ob‐ teur Telescope Making (ATM) II, by with the knife edge test, and match servatory, and a beau ful 6" J. R. Haviland (pp 212‐‐) and in ATM the convexes to that by interference Brashear/Warner & Swasey at Mt. III by Alan E. Gee, (pp 208‐‐), Charles fringes. If all looked good, I could Wilson, which I was privileged to L. Woodside (pp 565‐‐) and James H. then test the whole lens and, sup‐ 21 THE OBSERVER Adventures with the Refractor Part II posedly any error remaining would when the order was delivered I was the R.A to the hub of the drive gear. be on the back of the flint, which able to keep the spare set. This way, using the RA slow mo on could then be dealt with according‐ doesn't affect the drive rate, and ly. A er polishing I was somewhat In the first part I talked about the therefore the RA circle carried on gra fied that the focal length machine shop educa on. By now the gear doesn't get out of me. seemed close to the design, and my dad and I had the lathe, drill Since the lead screws on the tan‐ with an eyepiece the color correc‐ press with X‐Y and rotary table and gent arms straight and the mo on on was reasonably good. I tried to all. Also, the L.A. area is a paradise is along the arc of a circle, the figure these glasses with limited for nkerers, as there is a major screw mounts and the nuts they success, finally no ng the lens was scrap metal yard seemingly on eve‐ engage must be able to swivel to terribly as gma c. A test with ry street corner! Also, even though avoid jamming. The worm on the crossed polarizers showed the this was California, USA people, main gear is spring loaded to elimi‐ dreaded colored "Maltese Cross" in back then, weren't as damned "sue‐ nate backlash, and allow for any the crown element, indica ng a happy" as they are today, so the "out‐of‐round" of the main gear. I large amount of strain in the glass. managers of these places let us go was complemented on this design Amazingly enough, this was the tramping around and pick up what at one of the star par es and it was crown element. The flint was fine. I we needed, weigh it, pay up and go. strongly suggested I get this patent‐ checked the other blanks I had, and What came of all this was the fabri‐ ed. I said I really can't. I stole this they too were strained. That put ca on of an equatorial mount, for en re concept from an 1880's vin‐ this telescope on the back burner. the 8" SC, pa erned, func onally, tage Warner & Swasey mount! The a er the Warner & Swasey at Mt. ball bearings are retained by The scene now switched to my first Wilson. This one was all machined threaded rings in the axes, which job, right out of school, with Valor from aluminum with 1.25 thick can be ghtened to provide preload Electronics. Tom Johnson, the own‐ walled tubing for the sha s, thread‐ to the bearings. The cover over the er, was fooling around a new type ed and set up at 90 deg to the sad‐ lower polar axis bearing is also a 3.5 of telescope. My first encounter dle plate and bearing housings. ‐inch hour angle circle. Since the with Tom was at a star party, where Again, ball bearings (some lessons sha s and housings are both alumi‐ he showed up with an 18" Casse‐ never get learned!) but this me num, there is no trouble with tem‐ grain. (See cover, Sky & Telescope, there was adequate damping in the perature changing this preload. This March 1963) Remember, this was design of the clamps and the bear‐ equatorial head is supported by a the mid '60s, and aperture fever ings could be preloaded to some stout old transit tripod. The tele‐ stopped at 12.5", maybe a 16 or extent. The drive is a 6.25" 100 scope this mount was built for was two. This 'scope didn't perform all tooth brass worm gear, a 16:1 re‐ the 8" SC for which I subsequently that well, and Tom tried some rede‐ duc on and a 1 RPM motor. But completed the tube assembly. The sign and, skipping over the details, wait! That's 1600:1! Thanks to the details of this telescope will be told his fiddling led to serious break‐ slot car hobby I obtained the gears later. throughs in the manufacturability for a 20:18 gear train, and voila! of the 4th order aspheric plates for 1440:1. The motor is mounted on While at Valor I remembered my the Schmidt telescope. This fooling the baseplate, the power is trans‐ failed 3.6" lens and asked our glass around led to what we know today mi ed to the gearbox by a short supplier if he had any sugges ons. as the Celestron Schmidt Casse‐ sha and universal joints. This sys‐ He said to bring the lens and maybe grain. I helped Tom develop this tem allows a li le flexibility as the his place could reanneal it or some‐ system and he was able to keep me la tude is changed. The slow mo‐ thing. When I got the lens back, it out of the army. Clearly a fair trade! ons are both tangent arms, the looked OK, but when I put it togeth‐ One op cal system we did while I declina on being the equivalent of er the performance really stunk. was there was an 8" f/12, using a a 691:1 gear reduc on, the RA be‐ Close examina on showed a sort of very fast f/1.6 primary. I made an ing 534:1. the Declina on is "fire polished" appearance on one extra set of op cs as a backup, and clamped to the bearing housing, side. It needed to be reground. As I THE OBSERVER 22
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ve.. Photo By: Jerry Mullennix 23 Island, called 2.5 Some being sign?" day A took in it leading tems posi thing Besides math" the A much grind this lens or now the era, Fairchild ed see know re ground the into it a guide out. director er this It 1961. and Adventures with the Refractor Part II wow! a pris ne, beau ful lens ele‐ aluminum tube and some other was used for the refractor by ro‐ ment! It was even AR coated, edged odds and ends from which to make ta ng the Dec. axis 180 degrees, to to 5" diameter and seemed to have the lens cell and rack and pinion fo‐ bring the slow mo on knob closer to a fairly long focal length, around cuser. The 5‐inch tube was cut off at the eye end. The mount could then 800mm or so. My ini al figuring 90 degrees at both ends and a coun‐ be used for either 'scope quite easi‐ showed the crown element should ter cell machined to fit on the end. I ly. With the design of this mount, have a focal length around 770mm tested the lens by autocollima on, with the refractor on it really looked or so. Mixed emo ons! and determined the last couple of like a telescope! A freak accident led millimeters of its diameter showed to the loss of the 8" SC (a story in I'd feel terrible grinding into this some error, so the clear aperture itself) a er which the mount was lens, but then again, hopefully, it'd was made to be 122mm. I had a 5‐ dedicated to the 5" I added exten‐ be a nice lens a er the surgery. inch thin ring, threaded on the out‐ sion rods and a flex cable to the Maybe I could leave this one alone side, so I threaded the back of the clamps and slow mo ons so they and match the flint to it, using other lens cell to match this ring. I cut a could be operated easily from the glass tools to shape it. Further dig‐ shallow groove in the countercell as eyepiece. ging produced a weakly nega ve clearance and when the lens is lens element (the flint) equally as mounted on the tube, this groove Paul Thayer, a long me member of pre y as the crown. Suddenly it hit prevents any possibility of the cell DAS handed me a big eyepiece one me. There is some guy out there ex‐ ring coming loose and the lens ele‐ night at a Chamberlin star party. He pec ng the delivery of a lens and is ments falling out. The lens cell is said "this thing is a pig! If you think highly disgruntled at receiving a cou‐ a ached by three sets of push‐pull ple of blanks! I called Lynn and told screws to allow for collima on. The you can use it, it's yours" It was a him I had what appeared to be a fin‐ focuser has a brass tube 2.8" in di‐ 63mm Plossl, war surplus, probably ished lens and that he'd goofed. ameter with a 7" travel and a 2.5 the one described in MIL‐STD 141, When the customer for the lens inch holder diameter. I hate refrac‐ Op cal Design. I tried it on my 12.5, called to give him hell, he can ex‐ tor focusers with small travel! Once I and it didn't work well at all. Much plain the mix‐up, and in the mean got these components put together me I'll get this in the return mail. the balance point was only about a too low a power, exit pupil too big Lynn said "no, no goof. You wanted quarter of the way down the tube. It and so on. But what about at f/15. a 5" crown and flint, that's what you worked but looked sort of silly. This More op cal cer fied duct tape, got" "But this is a finished lens!" "So thing needed weight at the bo om and I tried it on the 5" Worked what, one crown, one flint..." 'but..." end. I solved this by moun ng my nicely! 28X, 1.8 degree field. Nice. I "Don't know if its any good or not. I 60mm Polarex as a guide telescope, found it in our scrap glass locker. I which served a useful purpose and asked Paul if he really couldn't use apologize as I don't know which flint placed the balance near the middle it on his 4" f/10 refractor. He said it is, F2 or F4. The crown is BK7 for of the tube. Later I added a Unitron "no. It's a pig" so I machined up an sure. Enjoy..." I took the elements 10X40 finder, purchased from a adapter for it. One night, New outside and measured the combined friend, and a couple of sliding moon, I was in the middle of Neva‐ focal length. 1800mm! Just what I weights on the tube to rebalance for da with this setup and was poking was planning to make. Wow! No different eyepieces and accessories. grinding, no G‐sum process, but was The tube is fastened to a piece of 3" through the Southern Milky way. this thing any good? Scrap glass? I channel with stainless steel hose Dark nebulae, li le star clusters, taped them to the end of a long clamps. The channel is bolted to the black sky and subtle contrasts, nee‐ cardboard tube and looked at Jupi‐ saddle plate on the mount's Declina‐ dle sharp images all the way across ter and a few stars. It was good. on axis the 1.8 degrees! This made a be‐ Very good. Mount? You may have guessed. The liever out of me and popped the I obtained a 5" diameter 5 foot long 8" SC mount talked about earlier myth that an f/15 can't be a richest
THE OBSERVER 24 Adventures with the Refractor Part II field telescope! With other, more normal eyepieces 2012 Canadian Observers Handbook ‐ $ 24 pre‐ this telescope is superb for double stars and the plan‐ paid orders only. Something new for 2012. In‐ ets, especially when the seeing is marginal and the cluded will be a CD with all the 12.5 would need to be stopped down. With a Herschel catalogues from the observing wedge and #10 welders filter the Sun can be spectacu‐ handbook and an observing pro‐ lar with all the fine detail in sunspots and spot groups gram. h p://www.rasc.ca/ as well as the granular appearance of the photo‐ handbook/ Send payment to sphere. This telescope is primarily used on the Sun, John Land by Nov 18 address is on Moon, planets and double stars, but is a capable rich‐ the website under Join. est field with the 63mm eyepiece. It has fulfilled the Digital Astronomy publica ons – Both Astrono‐ desire for a really nice refractor. It saw first light about my and Sky & Telescope magazines have digital 1973, and has been used con nuously ever since. A subscrip ons available for computer, IPad or medium sized refractor is a real pleasure to use, and a smart phones. If you already subscribe to 5" seems just the right size, balancing performance their print versions through the club discount, and portability. go to their websites to see how to add a digital version to your subscrip on. Our you may chose an all digital subscrip on.
Club rates for print versions are $ 33 Sky & Tele‐ 2012 Astronomy Publica ons scope $ 34 Astronomy. The club also received a promo on no ce from by Sky & Telescope Magazine.
For renewing or star ng a subscrip on by De‐ The Mayan’s may have run out of me on their cember 9 at the club member rate of $ 33. calendar in 2012, but Astronomers are eagerly awai ng many awesome events. Some 2012 You will receive a Mars DVD ‐ ‐ 2012 Sky Start‐ highlights include a sunset Solar Eclipse May er Pack with Almanac. 20, June 4 par al Lunar eclipse at sunrise, June 5 – Messier and Caldwell cards ‐ ‐ Let’s Go Star Long awaited Solar Transit of Venus Gazing booklet ‐ ‐ Sky & Tel Decal.
2012 Astronomy Wall Calen‐ dars for only $ 10 Twelve months of Deep Sky photos packed with informa on on astronomical happenings for the year. Our supply will go fast so bring exact change or a check to the mee ng. Sneak Pre‐ view at h p://lib.store.yahoo.net/lib/yhst‐ 22106725251441/68165spread.pdf
THE OBSERVER 25 ASTRONOMY CLUB OF TULSA – MINUTES - BOARD MEETING SAT NOV 5,
The meeting was held at the Broken Action Item No. 2 – Observatory After discussion about events at Arrow Library, 300 W. Broadway, Bro- Opening and Closing Procedures for TASM and Bass Pro, the board decid- ken Arrow, OK. All Star Parties ed to continue to do both, and to President Ann Bruun called the meeting After discussion about offering keys to have sign up sheets for members to to order at 10:15 AM. our new members after walking them commit to public outreach events. through the opening and closing proce- Tamara read the mintues from the last Chris also does not feel we should dures, Chris said that he will write up the board meeting, which was on Septem- procedures. He also has a new AT&T charge ACCREDITED schools to come ber 10, 2011. key and it works. to our public events, as that falls under Action Item No. 1 – Alternate Dark the outreach and education part of what Action Item No. 3 – Logistics During Sky Site we do. Catherine will bring sign up Public Star Parties There was discussion about finding a sheets for our public events to the din- dark sky site for the membership, with Chris needs about 5 people to efficiently ner on Nov. 11. pros, cons, cost, maintenance, conven- run a public star party. He has spoken to Action Item No. 5 – ACT 2012 Events ience for members, terrain, darkness of the lady who is in charge of student Calendar sky, etc. being brought into considera- community service at Cascia Hall and tion and about forming a committee to investigate possibilities. Ann would like Chris can get students to take money, We went over the 2012 calendar. The for a committee to bring forth 3 possible walk the grounds, and do whatever else Messier Marathon is on March 24. Ann sites for consideration. Tony suggested needs to be done. This gives the kids had a list of suggestions from John 5. Tom suggested a deadline of June 1. their community service hours as well as about some of the dates, which she Ann made a proposal to form the com- helping us. Catherine said her high- shared with the board. Easter is on mittee. Tony made motion to allow a school aged daughter and her class- April 8, so we could move the ACT TCC committee to form to look into possi- ble dark sky sites and offer chairman- mates could possibly help as well. Chris meeting to March 30. November 16 ship to Brad Young. Catherine se- needs one member to relieve him on the was suggested for the 2012 dinner conded, all in favor, motion carried. telescope. Tamara volunteered. Chris’ meeting. Another item on that list was From the Treasurer: dome shows are typically 6 objects and either moving the date for the December take about 30 minutes. The board de- meeting, but after discussion among the John had to leave at 11, so he went over the Club papework for the officers cided to allow Chris to have Cascia board, it was decided that we just skip to sign. John made a motion to ap- Hall students assist with logistics. the meeting due to its close proximity to prove the changes to the signers on Also, there will be a scope class for of- the holidays. Wells fargo account to include Ann ficers. Bruun, , President, Lowell A. White, There was no other business, so Ann Vice President, and John Land , On the subject of our 75th Anniversary, adjourned the meeting at 12:05 PM. Treasurer. Bill seconded. All in fa- Chris suggested for our public events vor, motion carried. that we trailer-mount the old 16 inch tel- There was also discussion about the escope, attach a CCD camera and lap- Nov 11 dinner. Ann suggested just buy- top, and we can transport the telescope ing bagged salad and dressings to add and use it at public events. Chris to the meal. John said that 57 people signed up for the dinner, 64 seats have asked for board’s approval to move been reserved. There was also a sug- forward with it. After more discus- gestion about name tags. sion, the board decided to allow him John made motion to invite Ron and to do this. Maura Wood to be lifetime members, Action Item No. 4 – Sidewalk Astron- Tony seconded. All in favor, motion omy and TASM Events carried.
THE OBSERVER 26 OBSERVER CLUB OFFICERS BOARD MEMBERS AT LARGE
President Ann Bruun 918‐231‐0301 Stan Davis 918‐294‐3196
Vice‐President Tony White 918‐258‐1221 Teresa Davis 918‐637‐1477
Treasurer John Land 918‐357‐1759 Tim Davis
Secretary Tamara Green 918‐581‐1213 Bill Goswick 918‐742‐6146
Catherine Kahbi 918‐230‐8480
APPOINTED STAFF Tom McDonough 918‐851‐2653 Newsle er Editor Jerry Mullennix MEMBERSHIP INFO Facility Manager Chris Proctor 918‐810‐6210 Astronomy Club of Tulsa membership ($45/year) includes membership in the Astronomical League Membership Chair John Land 918‐357‐1759 and subscrip on to ACT’s “Observer” and AL’s “Reflector”. “Astronomy” ($34/year) and “Sky and Observing Chair Chris Proctor 918‐810‐6210 Telescope” ($33/year) are also available through Group Director Tamara Green 918‐581‐1213 the club. For more informa on contact John Land at 918‐357‐1759. Permission is hereby granted to re‐ Webmaster Jennifer Jones print from this publica on provided credit is given to the original author and the Astronomy Club of Night Sky Network Teresa Davis 918‐637‐1477 Tulsa “Observer” is iden fied as the source.
Jim “O’Toole” Millers—Astro Words of Wisdom: “Say what you want, but as I approach the speed of light it means I have to get up and go to work.”
ACT welcomes your ques ons, sugges ons, comments and submissions for publica on. Please send all in‐ quiries to [email protected]
All Rights Reserved Copyright 2011 Astronomy Club of Tulsa.