The OBSERVER the Newsletter of the Twin City Amateur Astronomers, Inc

The OBSERVER The Newsletter of the Twin City Amateur Astronomers, Inc.

October 2003 Volume 28, Number 10 Observing Programs —William Carney

OR A LONG TIME my interest the last year or so was Sandyʼs discus- In This Issue: waned in astronomy, due mainly to sion about the observing programs from a loss of a good friend and fellow Astronomical League and I was surprised Fobserver Weldon Schuette. But several to see from the hands that there were very years ago with the passing of time few people working on observing • Observing Programs...... 1 I realized that I was missing programs. Looking for something to being with other fellow rekindle your love of astronomy? observers and friends and After purchasing Perhaps these may help... I sat down and won- some good eye- dered why I was not pieces I decided to • TCAA Calendar ...... 1 observing. I finished start simple with Use our calendar to mark the Lunar Club in the Astronomical your calendar. ʻ99 but this still did Leagueʼs Urban not really rekindle Observing Club. • Power Observing @ SGO ...... 3 my interest. I came to At least I thought Just how fast can you do the realize that part of the it would be simple, Messier List? With an LX-200, problem was I needed new but from my location very fast! eyepieces and other equip- (almost downtown) it was ment, but with these purchased I quite a challenge. In the process • Sept. Observing Sessions...... 4 thought well maybe there is something of doing the program, I rekindled my Weʼve been busy in else. I finally realized that I was not chal- interest in doing more observing and in September... lenged or had the desire till recently to doing other observer programs as well. I try any observing other than some basics. even discovered a keen interest in observ- • POSs Past, Present & Future .4 One of the few meetings I attended in continued on page 2 ... and in October, too! Expand Your Mind @ the TCAA Monthly Meeting • The SGNC Chautauqua...... 6 10 November, 2003, 7 PM, ISU Planetarium The TCAA was there (well, at least a few of us were...)

• Weather & the Internet...... 8 A handsome stud writes TCAA Calendar about the weather. Monday, 27 October, 2003, 5:30-7:15 PM, SGO School Observing Session (SOS!) • HST Deep Field...... 9 See what 84 hours and the Saturday, 1 November, 2003, 6:00-8:00 PM, SGO HSTʼs newest camera can Public Observing Session do for you! Monday, 10 November, 2003, 7:00 PM, ISU Planetarium • Treasurerʼs Report ...... 10 TCAA Meeting. Presenter: Rebecca Wenning

• TCAA Crossword...... 11 Saturday, 29 November, 2003, 6:00-8:00 PM, SGO Pencil? Wits? Go! Public Observing Session

• Welcome Mat ...... 12

The Observer The Newsletter of the TCAA, Inc. The Observer is a monthly publication of the Twin City Amateur Astronomers, Inc., a non- continued from p. 1 profit organization of amateur astronomers interested in studying astronomy and sharing ing more planetary nebulae. In fact, the If you are a beginner, start with the Uni- their hobby with the public. Astronomical League currently does not verse Sampler or Messier Club. You have an observing program specifically could try the Urban Observing Club, for planetary nebulae. but I recommend that for slightly more TCAA Officers experienced observers. Programs such as President Dan Meyer To recap, we are affiliated with the Lunar Club, Meteor Club and Planetary 309-874-2923 Astronomical League which has quite a Observers Club are also good starters for [email protected] few observing programs for members to beginners as well. For more experienced Vice-president Neale Leumkhl accomplish. When finished you get a nice observers you can try just about any of 309-378-4335 certificate and pin. I will list current pro- them, but you might start with the Lunar [email protected] grams below briefly. Club, Urban Observing Club, Herschel 3rd Director Jim Swindler 400, and Double Star Club . 309-452-3936 Lunar Club, Urban Observing Club, Uni- [email protected] There are a few basic tips I will share 4th Director Duane Yockey verse Sampler Club, Binocular Messier 309-452-3936 Club, Deep Sky Binocular Club South- with you on doing these programs. It does [email protected] ern Skies Binocular Club Messier Club, help a lot if you have good sky charts or a 5th Director Carl Wenning Herschel 400 Club, Herschel II Club, sky chart program that can print out cur- 309-438-2957 Caldwell Club, Arp Peculiar Galaxy Club rent sky maps. This can be very crucial [email protected] Galaxy Groups & Clusters Club Asteroid for finding a 8, 9, 10, 12 or greater deep Treasurer Duane Yockey Observing Club, Double Star Club, Earth sky object especially from light polluted 309-452-3936 Orbiting Satellite Observing Club Master areas. It also helps to list all the items in [email protected] Observer Club Meteor Club Planetary an observing program by constellation. Secretary Carl Wenning I currently have the Herschel 400 list in 309-438-2957 Observers Club, Sunspotters Club Sky- [email protected] puppy Club three large notebooks including several Property Manager Sandy McNamara printed charts for each item and sorted 309-379-2751 Some of these are self explanatory. Some by constellation. This allows you to pick [email protected] do require some hard work and even a constellation and observe all items in travel. I intend to do the Southern Skies that one then move on. I found that I Binocular Club and the Caldwell Club missed an object or two and had to wait The Observer Staff which require some travel to the southern six to nine monthʼs before it was visible Editors Michael Rogers hemisphere. I am currently working on again. For the Lunar Club, time listing is Jean Memken several programs including Herschel 400, very critical. For some craters and other objects on the Moon you only have one or Production Benjamin Rogers Asteroid Observing, Double Star, and Sarah Rogers Binocular Messier clubs and I plan to do two days observing time for them in any others in the future. Editorial Correspondence: continued on p. 7 The OBSERVER Editors 2206 Case Drive Bloomington, IL 61701

Articles, ads, etc., are due by the last weekend Support Your Local Planetarium! of each month. Items may be e-mailed to: [email protected], or [email protected]

Dues $40.00 per household, per year $25.00 for members over 60 $25.00 for newsletter only $ 2.50 for a single newsletter copy 3

The Observer The Newsletter of the TCAA, Inc. Power Observing at the SGO The Observer is a monthly publication of the — Carl J. Wenning Twin City Amateur Astronomers, Inc., a non- profit organization of amateur astronomers interested in studying astronomy and sharing N FRIDAY AFTERNOON, Sep- included observations of 19 objects for a NGC 6790 in particular showed very pro- their hobby with the public. tember 19, I was returning from grand total of 71 in an hour and a half. nounced blue, even more discernable than two days of work in Springfield the famous “Blue Snowball” (NGC 7662) Owhen I drove by the SGO on my way During the session I found that there was in Andromeda. TCAA Officers back to Normal. The sky was very clear, no significant vibration in the telescope at low power; at least I was not bothered It has become evident that with the 12- President Dan Meyer and I decided then and there that I would 309-874-2923 go observing that evening. I felt that the by any ongoing shaking of the eyepiece inch LX200 even a relatively novice [email protected] conditions were ideal for becoming more image. I was still a bit dismayed by the amateur astronomer could view the entire Vice-president Neale Leumkhl familiar with the operation of the 12- lack of absolutely crisp images produced collection of Messier objects on a spring 309-378-4335 inch LX200. Earlier in the week Sandy by the telescope, but Iʼm beginning to evening, and all the Herschel objects in [email protected] McNamara had dropped off my key to wonder how much of the lack of defini- just a few sessions scattered over the 3rd Director Jim Swindler the observatory, and I was now an official tion might be due to the single eyepiece course of a few months. Imagine, it takes 309-452-3936 key holder in need of additional experi- that I used. This is something that still many capable observers using star-hop- [email protected] ence before working with people attend- needs to be determined. (Work on Satur- ping methods more than a year to view all 4th Director Duane Yockey day evening with other eyepieces showed 110 M-objects, and truly skilled observ- 309-452-3936 ing public observing sessions. I arrived at [email protected] the observatory shortly after sunset and the problem to be partially due to the eye- ers several years to view the entire list 5th Director Carl Wenning quickly aligned the telescope with the piece I was using on Friday evening.) Iʼm of 400 Herschel objects. Now it can be 309-438-2957 stars. I had decided earlier to put the tele- now a bit concerned, too, that the program done with very little exertion using the [email protected] scope through its paces, and see just how in the LX200 that calculates the position SGO. The power of the TCAA telescope Treasurer Duane Yockey many celestial objects I could find during of Mars has in it an error. I suspect that housed under the dome at the SGNC is 309-452-3936 the viewing session. the problem is not with the actual com- truly amazing! I have during this same [email protected] putation, but with the data set used to cal- time come to more fully appreciate the Secretary Carl Wenning I used my laptop computer to assist in culate the planetʼs position. While accu- “deep sky” articles of Sandy McNamara 309-438-2957 rately able to find Uranus and Neptune, I that have appeared in the TCAA Observer [email protected] this “marathon” session. Using Voyager II Property Manager Sandy McNamara v2.02 software from 1995, I was able to was not able to find Mars without having over the past few years. Now that the 309-379-2751 keep a good star map on my computerʼs to reposition the telescope. Has anyone many deep space objects she describes are [email protected] plasma screen so that Iʼd know exactly else found this to be a problem? much more easily accessible than before, what to look for. As the sky darkened, I I guess that Iʼll have to spend a bit of time aligned the telescope and then observed I also found that evening that for me the reviewing her articles in a new light. The Observer Staff Neptune, Uranus, and Mars. During the visibility of extended objects was about Editors Michael Rogers next phase of the session I concentrated 10th magnitude in the 12-inch telescope. I Jean Memken my observations along the southern was able to find the 6.6 magnitude globu- meridian, in Sagittarius and the surround- lar cluster NGC 6541 (at a declination of Production Benjamin Rogers nearly – 44 degrees in Corona Australis) Sarah Rogers ing area. Between 8:15 to 9:15 p.m. I observed 52 Messier, NGC, and I.C. when it was only two degrees above the Editorial Correspondence: objects in the vicinity of the galactic cen- southern horizon! This is perhaps the The OBSERVER Editors ter! These included open clusters, globu- most southerly celestial object I have 2206 Case Drive lar clusters, bright nebulae, planetary observed from central Illinois, and anoth- Bloomington, IL 61701 nebulae, and a galaxy or two. Granted, er testament to the amazing ability of the Skyline! I wasnʼt spending much time observing LX200 pointing system. I was similarly The Official Voice of the ISU Articles, ads, etc., are due by the last weekend objects – I was most interested in seeing impressed that I was able observe some Planetarium/TCAA of each month. Items may be e-mailed to: how many objects I could find quickly. of the most distant objects I had ever [email protected], or [email protected] During the first hour of observations, I seen within the Milky Way – including averaged one object every 69 seconds! a globular cluster at a distance of some Dues The rate at which I was able to find deep 70,000 light years. The sky was excep- $40.00 per household, per year 438-5007 tionally dark and clear, and provided one $25.00 for members over 60 sky objects dropped to one object every $25.00 for newsletter only 95 seconds between 9:15 and 9:45 p.m. as of the best Milky Way views I have seen $ 2.50 for a single newsletter copy I became physically tired from stooping in recent years. Another of the remarkable over the computer and telescope, and had things I observed were planetary nebulae to move the dome regularly to view other in relatively large numbers, and some regions of the sky. This latter half hour showing a very distinct color. Aquilaʼs 4 5

Scheduled September Sessions Successful — Carl J. Wenning

OME 15 TCAAerʼs and guests observing session at Sugar Grove Nature until about 10:15 p.m. at which time the showed up for the members-only Center. Many members of the general sky had once again become overcast. At observing session at the Sugar public showed up in the hope of observ- the peak of the observing session, the SGrove Nature Center observatory on Sat- ing Mars. The evening started off under a entire parking lot was full of cars, and urday evening, September 20. Those who mostly cloudy sky, but with small open- some TCAA members estimated that with arrived early in the evening were able to ings here and there the expectation was people coming and going, the count of the observe a fair number of celestial objects that the Red Planet might yet be glimpsed. general public possibly exceeded 75. including Mars, Uranus, Neptune, open and globular clusters, a planetary nebula, Carl Wenning presented at 45-minute “sky The following TCAA members (probably and the galaxies of Andromeda. Nearly all talk” beginning at 7:45 p.m. using Voyager an incomplete list) operated telescopes: those in attendance were relatively new II computer software. At 8:20 p.m. Dan Dan Miller, Dan Meyer, William Carney, members. Meyer pointed out that a clear patch of Mike Rogers, Jim Swindler, and Duane sky had finally made its appearance over- Yockey. Thanks to all who made both On Saturday evening, September 27, head. By 8:30 p.m. viewers were at the observing sessions such a success. some 50-75 members of the general pub- telescopes. Observing continued with sky lic joined about 10 TCAAers for a public watchers looking between passing clouds

Observing Sessions Past, Present, and Future — Michael P. Rogers

N OCTOBER 13th, we, ahem, Meanwhile, the sky remained resolutely, presentation, etc., etc. As usual, check the attempted to have an observing almost obstinately blue, with nary a cloud mail list/web site for last minute changes. session for students of Prairie in sight. At 3 PM, it looked that way; at OLand school. Two minor problems arose, 4 PM, it was still blue; and yours truly The Challenger Learning Center: On one of which was self-inflicted. First, was feeling stupider and stupider by the Saturday, 18th October, we had an observ- yours truly, in scheduling said event, for- minute. But, a ing session out on the got about the fact that there was a conflict little after 5 PM, airport tarmac for the with a TCAA public meeting — one in from about 3500 Challenger Learning which he was scheduled to give a presen- feet, the cavalry Center. The event began tation about celestial coordinates. Oops. appeared in the with a chili supper in the A quick note was e-mailed to the board guise of a thin late afternoon, and we and the TCAA list, and it was decided, bank of clouds started at 7 PM. Yours rather than disappoint 80+ students and that could barely be discerned in the truly made a brief presentation using parents, to go ahead with the event. Northwest; by 6:30 the sky was nearly Starry Night (with many thanks to Carl, overcast. Chalk one up for NOAA! who fortunately had the right computer The 13th of October started off as as cable with him!), and then the crowds pleasant a Fall day as one could hope for, The SOS (Student Observing Session), dispersed to the telescopes. In attendance with a totally clear, deep blue sky. At 1 Mark II: The event has been postponed for the TCAA were , in alphabetical order, PM, I consulted the latest NOAA weather until 27th October, from 5:30 - 7:15 PM, Jean Memken, Dan Meyer, Dan Miller, forecast (www.noaa.gov), and it predicted still at the Sugar Grove Observatory, and the Rogers clan, Carl Wenning, and Duane overcast skies by 7 PM. Feeling like a will be combined with an observing ses- Yockey. The turnout was decent — 25-30 complete fool — those blue skies had sion for Brigham Elementary students that — and the Challenger Learning Center turned to a mocking shade of blue, and had previously been scheduled for that staff were highly complimentary. They contrails with the words, “Go on, cancel, date. The upshot of this is that we may talked about doing it once a month :-0. I dare you!” were starting to appear — I have 130+ students and parents, and we telephoned the Prairie Land teachers to really could use some help! We will need That may be a tad much, but there are postpone, and sent out an e-mail on the people to operate telescopes, hand out some obvious tie-ins between the TCAA TCAA mail list. brochures/star charts, point out constel- and the CLC, and this event helped high- lations, do traffic control, run a computer light those. 4 5

The Sugar Grove Nature Center Chatauqua —Michael P. Rogers

HE SUGAR GROVE Nature Cen- ter held its first “Chautauqua” on 11 and 12 October. The TCAA was Tthere, both with a booth and volunteers. Jim Swindler, Duane Yockey, and Sandy McNamara did booth duty. Dan Miller and yours truly served in a volunteer capacity with the SGNC — the former for both days, during which time, after a rig- orous driving test, he was deemed suitably trustworthy to drive the shuttle bewteen the parking lot and chautaqua proper. The latter worked for only the Saturday, and was deemed suitably trustworthy to be entrusted with garbage detail.

The Chautaqua itself was superbly run, and had good crowds, and terrific enac- tors. The images at right show Jim at our booth, and two TCAAers about to fence under the expert direction of a 18th cen- tury French soldier.

Meade now makes a 14” LX-200 for $4200. This has been a subliminal message... 6 7

Orionids - from Halleyʼs Comet... — NAMN

CTOBER BRINGS OUR fall easily recognizable constellation in the ocean and atmosphere - and published the season - and our ʻfalling starsʼ northern winter sky. In one version of first meteorological chart in the world. He from the constellation of Orion. ancient mythology, Orion was the son of catalogued 341 southern hemisphere stars, OWhether you are a beginning observer, Poseidon, the sea god, and Euryale, one and discovered a star cluster in Centaurus. or a serious observer gathering data for of the Gorgonʼs sisters, and was born in He made the first complete observation of meteor research, this meteor shower holds the Greek province of Boeotia. He was a transit of Mercury. Halley urged Newton many delights! a handsome hunter - and enjoyed both to publish his ʻPrincipia Mathematicaʼ, hunting and women. He fell in love with and paid for the costs out of his own The Orionids (ORI) reach a maximum Merope, the daughter of King Oenopion pocket. While sailing the Atlantic Ocean on October 21st, at 21h UT, according to of the island of Khios, and was set a task in command of a warship, courtesy of the IMO, the International Meteor Orga- by the king in order to win his daughter. King William III, Halley made studies of nization, 2003 Meteor Shower Calendar. The king went back on his deal, Merope longitude and tides. In the realm of com- They can be seen from about October 2nd told about Orionʼs rough treatment of her, ets, Halley believed that elliptical orbits through until about November 7th. ZHR and Oenopion blinded Orion and ditched might exist. He believed that the comets rates at maximum are about 20 meteors him on a seashore. Orion recovered his of 1531, 1607 and 1682 were all the same per hour. ZHR refers to Zenithal Hourly sight, with help from Eos, the goddess of comet - a periodic comet - and predicted Rate, and is the number of meteors, on the the dawn, and set off for vengeance. that it would return again in 1758. When average, that an observer would expect to the prediction came true, after Halleyʼs see if they were out under a dark country He traveled to the island of Crete search- death, the periodic comet was renamed in sky, and if the radiant, the area in the sky ing for King Oenopion, and met Artemis, his honor. where the meteors seem to come from, is the beautiful goddess of the Moon. Orion directly overhead. These are fast meteors, and Artemis fell in love, and he forgot Halleyʼs Comet has been traced back to with a velocity of about 66 km/s. about vengeance. However, Artemis the year 240 B.C. According to Kronk, forgot about everything else in her pas- “the computed motion of the comet indi- According to the IMO: “Octoberʼs waning sion for Orion - and she forgot her duty cates it would have appeared in the east, crescent Moon partly favors the Orionids to carry the Moon across the sky. After moved through northern skies, and then near their best. They are noted for having a month with no moon, Artemisʼ brother would have been seen in the western sky”. several maxima other than the main one Apollo, god of light and other things, got The closest approach of the comet to earth above, with activity sometimes remaining fed up and decided to get rid of Orion. was in the year 837, when we were sepa- almost constant for several consecutive One day when Orion was out swimming, rated from the comet by only 3.2 million nights centered on this peak.” Apollo challenged Artemis, a good bow- miles, .0342 AU, Astronomical Units. The hunter, to hit a small dark object a long tail reached about 60 degrees across the A good diagram showing where these distance away in the water. Artemis took sky. The recent appearance of Halleyʼs meteors come from in the sky can be the challenge - and unknowingly killed Comet in the 1980s produced a tail of found on Gary Kronkʼs excellent ʻCom- her lover. She was devastated. She took about 15 degrees in length, and a maxi- ets and Meteor Showersʼ website at Orionʼs body to her nephew Esculapius, mum brightness of about 2.6, fainter than http://comets.amsmeteors.org/meteors/ god of medicine and healing, to try to the stars of the Big Dipper. Halley is not showers/orionids.html A more detailed make him live again. A thunderbolt from one of the brightest comets of our time sky map showing the movement of the Zeus intervened, and Orionʼs body was - but it is one of the most well publicized radiant position over time can be found on destroyed. Artemis wept, and set her lover due to the history of its discovery. Some the IMO website at http://www.imo.net/ among the stars. photos of Halleyʼs Comet can be found calendar/cal01.html#Orionids. At the time on Kronkʼs ʻCometographyʼ website at of maximum activity, around the 21st, The Orionid meteors are debris from the cometography.com/pcomets/001p.html the radiant will be at 095 degrees, ie. RA famous Halleyʼs Comet. Both Halley and 6h 19.8m, Dec +16, which is located by his comet make for interesting reading as The discovery of the Orionid mete- following a line from the right star of the well. Edmond Halley was born in Hagger- ors themselves is generally credited to belt of Orion up through Betelgeuse, the ston, England in 1656, and died in Green- Edward Herrick in 1839. Precise obser- left shoulder star, and continuing on for wich, England in 1742. His accomplish- vations of the radiant were first made about the same distance again. ments were quite varied. He improved in 1864 by Alexander Herschel. The the sextant. He sailed to the southern continued on next page Orion is the most prominent and most hemisphere and collected data on the 6 7

continued from previous page

first measurements of meteor rates for the shower were done in 1892. The link between the shower and the comet came indirectly. It had been known since 1868 that the Eta Aquarid meteor shower in May was related to Halleyʼs Comet. In 1911, Charles Olivier mentioned the simi- larity of the orbit of the Orionids to that of the Eta Aquarids - and hence the first link- age in turn was made to Halleyʼs Comet, although it was not generally accepted until a number of years later. Orion is easy to find in our night sky - if you need help, print off some of our online star maps at http://www.namnmeteors.org/charts.html

For details on what to record, if you want to contribute useable data, check out our NAMN Observing Guide at http: //www.namnmeteors.org/guide.html. The information to record while observing is fairly basic... data for each meteor, such as time it occurred, magnitude (brightness), shower it belongs to, speed, and other comments such as train left behind, or color. General information to record includes such things as how dark your Tonight you might be able to see Halleyʼs Comet again - or at least some pieces of it. It is widely thought that that the meteors from the Orionids meteor shower, which peaks tonight, are just small pieces of Halleyʼs Comet perceived sky is (limiting magnitude), and falling to Earth. During each pass near the Sun, a comet will heat up and shed pieces of ice and rock from its comments on weather and cloud cover. nucleus. This debris continues to orbit the Sun until either evaporating or being swept up by some large solar- Forms to record your observations can be system body. A piece of comet debris striking the Moon creates a small crater, but a piece striking the Earth found at www.namnmeteors.org/namn_ usually burns up in the atmosphere causing a brief, bright streak. Every year at this time the Earth crosses an old stream of bits from Halleyʼs Comet causing the Orionids display, named from the constellation (Orion) form.html and www.namnmeteors.org/ from which the meteors appear to originate. The streak below center in the above picture of the northern sky appendixC.html. Any questions on what to actually depicts a meteor from the Perseid meteor shower, a usually even more impressive display that peaks record, or how, can be sent to our NAMN every year in mid-August. Coordinator at [email protected].

continued from p. 2 excellent for pre-teenagers to borrow to So there is no excuse in doing a program. given month because of the shadow zones. work on that new observing program of If you are a beginner itʼs a good place to There are several good books that help the Skypuppy Club and even others like start. If you are an old experienced observ- in observing, one being the “Atlas of the the Universe Sampler. I started in astron- er you might even learn a few things or Lunar Terminator” by John Westfall. omy myself with a 60 mm scope of 700 rekindle that lost interest. You might just mm focal length on an altazimuth tripod. observe something you never did before. If you are thinking you donʼt have the It was not of much use but it did teach On a last note: I never observed the “Blue right equipment, then that is not a good me about scopes, eyepieces, focusing and Snowball” NGC 7662 in the Constellation enough excuse for not doing a program. other basics. It peeked my interest in get- of Andromeda before doing the Urban I did all most all the Lunar Club with the ting a larger scope to observe with and Observing Club. T.C.A.A.ʼs four inch Celestron refrac- in seeking out the astronomy club and its tor. The club has quite a few telescopes events. Other scopes are also available for So get out there off your chairs and do for members to borrow. I even recently loan if you choose to use them. some observing, you might see something donated two 60 mm refractors which are really neat. 8

Weather and the Internet — Michael P. Rogers

STRONOMERS have a vested for Terminal Aerodrome Forecasts — are time, and written with a Z). interest in accurate and timely very precise, but technically only apply weather information. Unfortu- within 5 miles of an airport. They are The easiest way to understand this is by Anately, most of the forecasts distributed issued approximately 4 times per day, and example: let us look at a recent TAF for in the “popular” media are usually out-of- each forecast covers the next 24 hours. By Peoria, from weather.noaa.gov/weather/ date, sketchy, or (gasp!) simply wrong. studying multiple TAFs, it is possible to taf.shtml get an excellent idea of what the weather More accurate weather forecasts are out gods have in mind. AFs — short for KPIA 222321Z 230024 VRB03KT there — all it takes to find them is an Area Forecasts — cover several states, are P6SM BKN100 Internet connection and a web browser. issued only 3 times per day and provide FM0700 VRB03KT P6SM the “big picture”. Airline pilots need AFs: SCT100 For general weather forecasts, nobody astronomers need TAFs. FM1300 36011KT P6SM does a finer job than NOAAʼs National SCT250 Weather Service. Just cruise over to http: NOAA does not issue TAFs for every FM2100 01008KT P6SM //www.crh.noaa.gov/ilx/, and you will find airport in the United States. In our area, SCT040 reasonably accurate weather, with excit- Champaign (abbreviated as KCMI), ing graphics, out to a week in advance. Decatur (KDEC), and Peoria (KPIA) This forecast, for KPIA, was issued on the Unfortunately, even here the forecasts lack are favored; for reasons of politics and 22nd of October at 2321 UTC, and valid detail, and hence raise as many questions economics, Bloomington (KBMI) is not on the 23rd of October from 0-24 UTC. as they answer: what does“partly cloudy” deemed worthy. However, interpolating mean, exactly? At what time, exactly, the forecasts at these 3 airports will amost At the outset (00 UTC), the winds are will those clear skies morph into partly always be sufficient. Weather tends to variable (VRB) at 3 knots (03), with +6 cloudy ones? Is there any point haul- come from the west, so the KPIA statute miles (P6SM) visibility. The sky ing out the telescopes? Or should forecast itself may be the most is broken at 10000 feet (altitudes are we just stay at home and watch relevant (although pilots, reported in 100ʼs of feet). “Broken”, a good astronomy documen- legally, need to familiar- abbreviated as BKN, is one of 4 categories tary? ize themselves with all of cloud coverage: aspects of weather, and Astronomers are not alone would be both in violation CLR — none at all in their desire for precision in of the law and foolish to FEW — 1/8-2/8 of the sky is obscured prognostication. Everyone cares rely on just a single TAF). SCT — 3/8-4/8 about the weather, to a certain BKN — 5/8-7/8 extent. It can be argued, however, that TAFs are written in an arcane, OVC — 8/8 pilots care about weather more than any- coded style that was appropriate when one else, for the obvious reason that they information was being sent by telegraph, Looking at line 3, we see that from (FM) are more susceptible to bad weather than but merely quaint in the era of gigabyte- 0700 UTC, the winds will continue to be anybody else. Wandering into a thunder- to-the-desktop networks. Supposedly variable at 3, with +6 statute miles vis- storm in a car is (usually) just an inconve- plain-English TAFs are available, but I ibility, but now the skies will be scattered nience; wandering into a thunderstorm in have not been able to find them. Fortu- at 10000 feet. From 1300 UTC (8 AM), a plane is (often) the first step in a NTSB nately, decoding them is not rocket-sci- the wind picks up and now comes from investigation. ence (nor is it astronomy :-). 360° at 11 knots, with clouds scattered at 25000. Finally, from 2100 (until 2400), No surprise, then, that NOAA labors All TAFs are essentially the same. They the winds will be from 010° at 8 knots, mightily to provide aviators with the best, begin by identifying the airport, time and clouds will be scattered at 4000 feet. most accurate, short-range weather fore- of issuance, and time of applicability. casts available. Anyone can access these Then, they give the winds, visibility, and Now you know the basics of TAFs, and forecasts, however, and this article will tell sky conditions. If these are expected to the next time you are contemplating an you how to do just that. change over time, then the TAF will be observing session, read them first: a few broken into sections, each covering a par- seconds on the Internet may save you a First, some background. Aviation fore- ticular time interval. Speaking of which, wasted trip! casts come in two flavors. TAFs — short time is expressed in UTC (called “Zulu” 8 9

A Strawman Design from TRW/Ball Aerospace 10

TCAA Treasurerʼs Report — September, 2003 — L. Duane Yockey, Treasurer

------OPERATING FUND BALANCE – August 31, 2003 - $ 682.21

Income

Cheyenne Adams (dues) - $ 40.00 Matt Hughes (dues) - $ 40.00 Bob Warfield (sen. dues) - $ 25.00

Expenses

None - $ 0.00

OPERATING FUND BALANCE – September 30, 2003 - $ 787.21 ------OBSERVATORY FUND BALANCE – August 31, 2003 - $ 815.14

Income

Donations (September POS) - $ 44.00 Interest (July, Aug. & Sept.) - $ 0.56

Expenses

None $ 0.00

OBSERVATORY FUND BALANCE – September 30, 2003 - $ 859.70 ------TOTAL TCAA FUNDS – September 30, 2003 - $ 1,646.91 ------

Sugar Grove Observatory

Listing of Official Keyholders (Paid $10 deposit/$5 renewal)

Jim Swindler (April 2001) Duane Yockey (April 2001, renewed Jan. 2003) Sandy McNamara (June 2001, renewed Jan. 2003) Dan Miller (August 2001) Michael Rogers (August 2001) Dan Meyer (February 2002, renewed March 2003) William Carney (March 2002, renewed Jan. 2003) Vic Connor (August 2002) Neale Lehmkuhl (May 2003) 10 11

The Observer Crossword —Observer Staff

ACROSS 1 Penziasʼ proof 5 Former name of Thailand 9 Large container 12 Wool cleaning brush 13 Otherwise 14 Guardian of the Dark (Sky) 15 Haul 16 Sleeveless garment 17 Chafe 18 Mountain goat 20 The USPSʼs favorite nebula? 22 Annie Jump .... American astronomer 25 Automatons 26 The last Greek letter 27 Disk on which 84% of starʼs light is concentrated 28 Insect 29 Arrest 30 Tavern 33 State of USA 35 Monetary unit of India 37 The unit of gas pressure 40 Fermented soybean cake 41 Group of eight 42 Tides that attain the least height 43 Solicit 44 Moon of Saturn discovered in 1672 46 Reflected sound 50 Large flightless bird 23 Atomic mass unit 48 Hasten 51 Rowing implements 24 Negative 49 Lyric poem 52 Sudden assault 25 Curved bone 53 Long-tailed rodent 27 Anglo-Australian Observatory, for 54 Protuberance short 55 Fencing sword 29 Naught 30 Small seed DOWN 31 Exploit 1 The astrophotographerʼs toy 32 Exclamation of contempt 2 Lever for rowing 33 Wood sorrel 3 Brassiere 34 A member of the class of elementary 4 Border particles that interact by means of the 5 John Glennʼs Number strong force 6 Holly 35 Seed of a legume 7 Donkey 36 The unit of electrical current 8 ʻShooting starʼ 37 Work done per unit time 9 Constellation : The virgin 38 Pueblo Indian village 10 Mature 39 Corpulent 11 Progressive emaciation 40 Tantalize 19 Fur scarf 42 Dweeb 21 To endure 45 Monetary unit of Vietnam 22 Male swan 47 Head covering 12

The Welcome Mat Octoberʼs not nearly as scary when we have new members to welcome. A boo-tiful welcome to...

Ben Josefik Morris, IL

Todd Scarlett Normal, IL

The OBSERVER The Newsletter of the Twin City Amateur Astronomers, Inc.

Michael Rogers & Jean Memken, Editors 2206 Case Drive Bloomington, IL 61701

Dues Due? The Dues Blues If you see a check in the box above, it means your dues are due. To retain membership -- and with a new observatory, why quit now??? -- please send $40 to our esteemed treasurer:

Duane Yockey 508 Normal Avenue Normal, IL, 61761

As always, thank you for your support!!