The OBSERVER The Newsletter of the Twin City Amateur Astronomers, Inc.
July 2003 Volume 28, Number 7 TCAA Meeting Minutes —Carl Wenning, Secretary
HE MEMBERSHIP was called to • The July public observing session at the In This Issue: order in the ISU Planetarium at SGO was reasonably well attended. 7:03 PM by TCAA President Dan- Tiel Meyer. Sixteen members were in atten- Dan then called for a Treasurerʼs Report. dance. Dan provided Treasurer Duane • TCAA Meeting Minutes ...... 1 a short summary of Yockey noted that Star parties, field trips, Astrofest recent events. Among the treasury is in and a BIG Mars POS! Get these events were the good condition, with ready for a busy few months! following: all major bills for the year (insurance, • The June picnic at Sky Calendar, Astro- • TCAA Calendar ...... 1 Sugar Grove Nature nomical League, etc.) Use our calendar to mark Center was attended having been paid. your calendar. by about a dozen With the balance in members. Carl Wen- the black, Duane ning gave a short pre- noted that the Board sentation dealing with of Directors would • Alignment & Collimation...... 3 the Challenger Learn- gladly consider is your telescope feeling poorly? ing Center. Follow- making additional Take it to the A&C Clinic and ing these events, the membership began material purchases on behalf of the mem- itʼll thank you! an observing session at the observatory bership. Members should contact a Board that later was attended by additional club member with requests prior to the next members, as well as several individuals board meeting on August 13th. • Dragon Hunting ...... 4 from the general public. continued on next page Yet another Harry Potter tie-in :-) Alignment & Collimation Clinic Details on P. 3 • IL Dark Skies Star Party...... 6 Everything you need to know about the SGO TCAA Calendar • Telescope Collimation ...... 6 Saturday, 26 July, 2003, 6:00-8:00 PM, SGO Homework for the A&C Clinic Alignment and Collimation Clinic (see p. 3 for details)
Monday, 11 August, 2003, 7:00-9:00 PM, ISU Planetarium • Oldest Known Planet ...... 6 TCAA Meeting/Potluck/Movie (see p. 2 for details) But, oddly enough, it claims to be only 39! Wednesday, 13 August, 2003, Lewis, Yockey & Brown TCAA BOD Meeting (see p. 2 for details) • Treasurerʼs Report ...... 9 Friday, 22 August, 2003, 6:30-9:30 PM, Paneraʼs & MUO Field Trip to the Millikin University Observatory (details TBA) • Welcome Mat ...... 12 Monday, 30 August, 2003, 8:00 PM, SGO We have new members! Special Mars POS (see p. 2 for details) 2
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 Dan then announced the following public observing session on Saturday, their hobby with the public. upcoming events: August 30, at SGNC. The beginning time will be 8 PM, and will start with a talk about Mars by Sandy McNamara, TCAA Officers • Sandy McNamara will hold a telescope alignment and collimation session at perhaps assisted by other members. (Tom President Dan Meyer SGO on July 26, from 6 to 8 PM. Also Willmitch has consented to the joint ven- 309-874-2923 addressed will be techniques in the care ture, and will attempt to garner additional [email protected] and management of telescopes. The event support by holding a special session at Vice-president Neale Leumkhl will be held rain or shine. the planetarium earlier in the day using, 309-378-4335 perhaps, the support of a local NASA [email protected] • There will be an Illinois Dark Skies Star Solar System Ambassador. Tom will take 3rd Director Jim Swindler Party September 25-28 at the Jim Edgar advantage of the ISU News Service to 309-452-3936 Panther Creek State Fish and Wildlife promote both events.) [email protected] 4th Director Duane Yockey Area, 25 miles northwest of Springfield in 309-452-3936 eastern Cass County. There is a Septem- • There will be a Board of Directors [email protected] ber 1 registration deadline. See meeting on August 13, 2003, begin- 5th Director Carl Wenning http://www.sas-sky.org/ for additional ning at 6 PM at the offices of Lewis, 309-438-2957 details. Yockey, and Brown at 505 Main Street in [email protected] Bloomington. The membership is invited Treasurer Duane Yockey • Astrofest will be held at Kankakee to attend, but reminded that their voice is 309-452-3936 again this year. Astrofest is slated advisory only. [email protected] for September 18 - 20, 2003. Addi- Secretary Carl Wenning • The next TCAA meeting will be “Dinner 309-438-2957 tional info can be found online at http: [email protected] //www.chicagoastro.org. and a Movie” to be held in the ISU Phys- Property Manager Sandy McNamara ics Department. It will be a potluck, with 309-379-2751 • There will be a joint TCAA/PAS observ- the TCAA providing the main entrée; Carl [email protected] ing session near Mackinaw near the new Wenning will provide refreshments; Dan moon weekend of August 23rd. Meyer will bring the movie “Forbidden Planet.” The membership will bring a dish The Observer Staff • There will be an observing session at to pass, as well as their own dining plates Editors Michael Rogers Millikin University hosted by Mike Rog- and utensils. Jean Memken ers and Dan Miller on Friday, August nd At 7:40 p.m. Carl Wenning, former plan- Production Benjamin Rogers 22 . This will replace the members-only Sarah Rogers observing session held that month. etarium director (1978-2001), provided a talk dealing with the summer evening sky Editorial Correspondence: • With the opposition of Mars on August constellations. The event came to a close The OBSERVER Editors 27th, the TCAA in conjunction with the at approximately 8:20 PM. 2206 Case Drive ISU Planetarium will sponsor a special Bloomington, IL 61701
Articles, ads, etc., are due by the last weekend of each month. Items may be e-mailed to: [email protected], or [email protected] Skyline! Dues $40.00 per household, per year The Official Voice of the ISU Planetarium/TCAA $25.00 for members over 60 $25.00 for newsletter only $ 2.50 for a single newsletter copy 438-5007 3
The Observer The Newsletter of the TCAA, Inc. The Observer is a monthly publication of the Twin City Amateur Astronomers, Inc., a non- profit organization of amateur astronomers Alignment & Collimation interested in studying astronomy and sharing their hobby with the public. Clinic TCAA Officers Here is a quick quiz to see if you need the A&C Clinic. For each question, give yourself 5 points if you answered a), 10 points for b), President Dan Meyer and 25 points for c) 309-874-2923 [email protected] 1. Do you have trouble aligning your telescope? Vice-president Neale Leumkhl a) Yes 309-378-4335 b) No [email protected] c) Whatʼs alignment? 3rd Director Jim Swindler 309-452-3936 2. Do stars in your telescope look like ellipses? [email protected] 4th Director Duane Yockey a) Yes 309-452-3936 b) No [email protected] c) What does an electronic kiss have to do with astronomy? 5th Director Carl Wenning 309-438-2957 Now, total your points from each question. If you scored at least 0, then you need the Alignment and Collimation Clinic, so itʼs a [email protected] good thing itʼs coming right up! Treasurer Duane Yockey 309-452-3936 [email protected] Secretary Carl Wenning 309-438-2957 [email protected] Property Manager Sandy McNamara 309-379-2751 [email protected]
The Observer Staff Editors Michael Rogers Jean Memken
Production Benjamin Rogers Sarah Rogers
Editorial Correspondence: The OBSERVER Editors 2206 Case Drive Bloomington, IL 61701
Articles, ads, etc., are due by the last weekend 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 When: 26 July, 6-8 PM (Rain or Shine) $25.00 for newsletter only Where: Sugar Grove Observatory $ 2.50 for a single newsletter copy Fee: Are you kidding?? :-) Bring: Your telescope (if you have one) 4 5
Dragon Hunting! — Sandy McNamara
HE CONSTELLATION Draco history books as the home of Thuban only binoculars. 17 Dra also has a close is a large, winding string of stars (alpha Dra), which marked the location companion 3.4” away at position angle that covers much of the northern of the north celestial pole approximately 108 degrees that my 8-in telescope shows Tsky between Cygnus and Ursa Major, 5000 years ago and during the period at 150x. About midway between the drag- almost surrounding the Little Dipper of when many Egyptian pyramids were being onʼs head and the bowl of the Little Dip- Ursa Minor. As always, a good star atlas constructed. Due to a phenomenon called per is the mag 3 star zeta (22) Draco; its or chart helps to locate the main stars and “precession” the position of the “north only importance is that it helps to locate deep sky objects that follow. Draco, the star” changes over the centuries. Actu- the next doubles on our list
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to fill this “missing” spot in the catalog. Located 3 d SW of epsilon Dra, this is one of the fainter Messier objects and can be a challenge in small telescopes. My 8-in telescope shows a small oval galaxy form- ing a triangle with two stars to its NW and SW; the 12-in telescope more easily shows a bright lens shape.
NGC 5907 (misstated as NGC 5906 in some references) is my favorite type of deep sky object: a bright, extremely edge- on galaxy. You can find it 3 degrees from iota (12) Dra toward Bootes, about 1.5 degrees NE of M102. While beautiful in a 12-inch telescope, this is not extremely bright in an 8-in telescope but you should have no trouble seeing this large lens shaped galaxy as a dim needle of light stretching across your eyepiece field of This Hubble telescope image shows one of the most complex planetary nebulae ever seen, view. NGC 6543, nicknamed the “Catʼs Eye Nebula.” Hubble reveals surprisingly intricate struc- tures including concentric gas shells, jets of high-speed gas, and unusual shock-induced knots NGC 5982 is a small, roundish galaxy of gas. Estimated to be 1,000 years old, the nebula is a visual “fossil record” of the dynamics located sl N of the midpoint between iota and late evolution of a dying star. A preliminary interpretation suggests that the object might and theta Dra. The brightest in an E-W be a double-star system. The dynamical effects of two stars orbiting one another most easily galaxy row it forms with NGC 5981 6ʼ to explains the intricate structures, which are much more complicated than features seen in most its west and NGC 5985 7ʻ to its east; the planetary nebulae. The two stars are too close together to be individually resolved by Hubble two fainter galaxies usually require dark and instead appear as a single point of light at the center of the nebula. skies and at least an 8-in telescope for easy visibility. NGC 5982 itself shows Technical Stuff up in my 8” telescope as a small round Object Type RA DEC Mag Size/Sep Notes faint nebulosity gradually brightening to NGC 3147 Gal 10h 17m +73d 39ʼ 10.7 3ʼ X 2.3ʼ a sl brighter condensed core. I had dif- NGC 5866 Gal 15h 07m +55d 45ʼ 10.0 5.2ʼ x 2.3ʼ M102 ficulty seeing NGC 5981 in an 8-in tele- NGC 5907 Gal 15h 16m +56d 19ʼ 10.2 12.3ʼ x 1.8ʼ scope under semi-rural skies but NGC NGC 5982 Gal 15h 39m +59d 21ʼ 11.1 1.2ʼ x 0.8ʼ 5985 was visible as an oval nebulosity NGC 5985 Gal 15h 40m +59d 20ʼ 11.0 5.5ʼ x 3.2ʼ just E of 5982 in same field of view. It is 16/17 Dra DS 16h 36m +52d 55ʼ 5.4/5.5 90.0” PA 194 almost 3x larger but only half as bright 17 Dra DS 16h 36m +52d 55ʼ 5.4/6.4 3.4” PA 108 as 5982 so may be a challenge in smaller Mu (21) Dra DS 17h 05m +54d 28ʼ 5.7/5.7 2.0” PA 42 telescopes or more urban skies. Struve 2155 DS 17h 16m +60d 43ʼ 6.8/10.1 9.8” PA 114 Nu (24/25) Dra DS 17h 32m +54d 11ʼ 4.9/4.9 62.0” PA 312 NGC 3147 is a magnitude 11.3 almost Omicron (28) Dra DS 17H 37M +68D 45ʼ 4.6/7.6 34” PA 335 face-on galaxy located most easily by Psi-1 (31) Dra DS 17h 42m +72d 09ʼ 4.9/6.1 30.3” PA 15 moving 4d NE of bright galaxy M82 in NGC 6503 Gal 17h 49m +70d 09ʼ 10.2 6.2ʼ x 2.3ʼ UMa, it lies less than 1/2 degree north NGC 6543 PN 17h 59m +66d 38ʼ 8.1 22” X 16” Catʼs Eye of a bright mag 6 field star. Look for a 40/41 Dra DS 18h 00m +80d 0ʼ 5.7/6.1 19.3” PA 232 small sl oval glow that might be faint in small (4 to 6-in telescopes) but moder- For those working on varied observing projects: NGC 5866 is on the Messier list. NGC ately bright in anything larger. 5907 is on the Universe Club list. Stars 16/17, 17, mu, nu, psi-1, and 40/41 are on the AL Double Star list. NGC 3147, 5866, 5907,5982 are on the Herschel 400 list. 6 7
Illinois Dark Skies Star Party, Sep 25-28 — Sandy McNamara
HE SECOND ANNUAL Illinois include hiking, biking, fishing, boating, tricity and water; another 80 sites have Dark Skies Party will be held and horseback riding; many of the Lin- electric only. In order to reserve these September 25-28, 2003, at the Jim coln Heritage sites are also nearby. JPEC particular sites, you must reserve them TEdgar Panther Creek State Fish and Wild- is also just minutes away from grocery and pre-register with the Illinois Dept of life Area (JPEC), 25 miles NW of Spring- stores, restaurants and shops in the small Natural Resources (DNR). DNR can be field, Illinois in eastern Cass County, just nearby communities of Ashland, Chan- contacted at 217-452-7741 or by visiting west of New Salem State Park in Peters- dlerville, Newmansville, and Petersburg. www.dnr.state.il.us. Please note that the burg. This is a fairly new event but peo- general observing field has NO electric ple around the central US have been get- Registration fees of $35/person (age 13 service. Electric is only available at the ting excited about it and talking about it and over; children 12 & under are free) or cabins and RV sites. possibly replacing Astrofest in the future $55/family must be received prior to Sep- as a premier dark sky party. Less than a tember 1, 2003. Attendance will be lim- Registration forms will be available at 2 hour drive from Bloomington, it is the ited 1000. No registrations will accepted the July and August TCAA meetings, at closest major star party to our location. after Sep 1 and no on-site registrations are SGO, and can also be downloaded from available. Registration includes the cost www.sas-sky.org. More details about This area boasts some of Illinoisʼ darkest of tent camping only at the group camp the Illinois Skies Star Party, including skies. Naked eye views of 6+ magnitude sites; these sites are non-electric sites. star party rules, planned events, direc- objects are not uncommon. Plans for star A limited number of cabin bunks are tions, and information about JPEC, can be party events include guest speakers and available at $21/person for the weekend. found at www.sas-sky.org. presentations, and ATM astrophotography The campground adjacent to the general contests. Daytime activities at the park observing field has 18 sites with elec- Telescope Collimation — TelescopeHome.com ELESCOPE COLLIMATION is Telescope collimation is more of an issue two. Another problem is knowing when the process by which an instru- with Newtonian Reflectors and Schmidt- the reflections of the mirrors are exactly ments optical components are Cassegrain. Good telescope collimation centered. Just “eyeballing it” isnʼt precise Tbrought into precise alignment with its is particularly critical for “faster” Newto- enough; the reflections may appear to be optical axis and mechanical axis. nians, those with f-ratios of f/6 or lower. centered when in fact they are not. Once the telescope collimation is set, it will hold if care is taken in transporting The Collimating Eyepiece will take care In other words, telescope collimation is and handling the optical tube. However, of both of these problems, allowing you all about mirrors and/or lenses being cen- any sharp jolts can knock the mirrors out to achieve precise collimation with- tered and angled so that light entering the of alignment, as can jostling of the scope out “guessing”, and thus improve your telescope forms a sharp image precisely in in the trunk of a car or temperature chang- telescopeʼs performance. You can buy a the center of the eyepiece. If the optics are es over a period of time. Fortunately, these Celestron Collimating Eyepiece at Adora- not properly aligned, stars will appear not telescopes are equipped with adjustment ma for around $34.95. as pinpoints, as they should, but rather as screws that permit easy telescope re-col- flared, teardrop-shaped “comets”. limation. Testing Telescope Collimation
Collimation Fundamentals A common way of telescope collimation You can quickly determine whether your is the quick method. This is to simply telescope is properly collimated. Just Refractor and Maksutov telescopes are remove the eyepiece and look down the point it at a bright star and slowly rack the collimated at the factory and generally focuser tube to center the mirror reflec- image out of focus with the focusing knob. should not need further adjustment. If col- tions. Unfortunately this is not accurate If the telescope is correctly collimated, limation does become necessary later, it or a reliable method. For one thing, there the expanding disk should be a perfect is best to have it done at the factory, since is no way to know whether you are look- circle. If it is unsymmetrical, the telescope these telescopes usually possess no user- ing straight down the focuser tube; your is out of collimation. In reflectors and adjustable collimation settings. line of sight could be off by a degree or continued on next page 6 7
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Schmidt-Cassegrain, the dark shadow cast inspection usually suffices. If the primary For “spider-type” holders, this is usually by the secondary mirror should appear in is obviously not centered, it will need to done by turning the threaded rod that the the very center of the out-of-focus circle, be repositioned in its mirror cell. secondary mirror mount is attached to. For like the hole in a doughnut. If the “hole” single stalk-type holders, you may have to appears off-center, the telescope is out of Next, remove the eyepiece from the tele- bend the stalk to center the mirror. Refer collimation. scope. Look down into the open focuser to your telescopeʼs manual for more spe- tube. You will see the secondary mirror cific instructions. and mirror holder as well as reflections of the secondary mirror and its holder, the Now you need to adjust the tilt of the sec- primary mirror, and your eye. Itʼs pretty ondary mirror so that the entire reflection confusing. Refer to figure 1 below. of the primary mirror is precisely centered in the secondary mirror (and, thus, also Aligned Misaligned Now insert the telescope Collimating on the crosshairs of the Collimating Eye- Eyepiece into the focuser and look into piece). Use the three telescope collimation Collimating a Schmidt-Cassegrain the sight hole. Youʼll notice that the field screws on the secondary holder to adjust of view is narrower than it was when you the tilt. The reflection of the primary mir- With Schmidt-Cassegrain telescopes, col- were looking through the open focuser ror is centered when there is an even ring limation is best performed using a “star tube. Youʼll also notice that instead of see- of space between it and the outer edge of test” but reasonable collimation can be ing a reflection of your eye, you now see a the secondary mirror. Donʼt worry that achieved with the Collimating Eyepiece. bright annulus in the reflection of the sec- the reflection of the secondary mirror is There is only one collimation adjustment ondary mirror. The annulus is the reflec- off-center; youʼll fix that in the next step. for Schmidt-Cassegrain: the tilt of the tion of the polished 45-degree flat of the If you do not see the reflection of the pri- secondary mirror. Insert the Collimating Collimating Eyepiece. mary at all, the tilt of the Eyepiece directly into the visual back of secondary is way off, the telescope. Check whether and more tinker- the secondary ing with the The shadow of the secondary mirror will mirror is collimation appear as a dark circle near the middle of centered screws will the field-of-view. Adjust the three Allen- under- be neces- head screws located in the center of the neath sary. front corrector plate to center the second- the If the ary mirror on the crosshairs. Do not loosen focus- the screws more than two turns, or the er. secondary mirror could fall off its mount! Use Likewise, do not adjust the screw in the the middle of the secondary mirror cell. It holds the mirror in place. cross- mount Collimating a Newtonian Reflectors hairs is a at the single With the telescope pointed away from the bottom stalk, you Sun, look into the front of the telescope of the will have tube. Check that the secondary (or diago- Collimating to bend it nal) mirror is positioned in the center of Eyepiece as to the correct the tube; use a ruler if necessary to mea- a reference. The position. The sec- sure the distance from the center of the center of the second- ondary mirror is now secondary mirror holder to the inside of ary mirror should lie right at concentric, but the other the tube on different sides. You may have the intersection of the crosshairs. rings are not concentric. Refer to to adjust the spider vanes or stalk. Also, If it doesnʼt, adjust the position of the mir- figure 2 on the next page. check to see that the primary mirror is ror holder until it is centered. centered in the optical tube. A quick visual continued on next page 8
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Now itʼs time to adjust the tilt of the pri- mary mirror. Using the three collimation bolts at the bottom of the optical tube, located behind the primary mirror, turn one at a time until the secondary mirror reflection moves into the center of the primary mirror reflection. The spot in the middle of the primary mirror should be exactly centered in the
bright annulus. Refer to figure 3, top right.
Now, the view through the Collimating Eyepiece should resemble the diagram below. The reflection of the primary mir- ror is centered in the secondary mirror, and the reflection of the secondary mirror is centered in the reflection of the primary mirror. If everything is centered on the crosshairs of the Collimating Eyepiece, the telescope is in collimation -- tuned up and ready for action! The telescope is now properly collimated. All rings are concen- tric. Refer to figure 4, at bottom right..
Collimating your telescopeʼs optics will become second nature to you when you perform this task on a regular basis. 8 9
Oldest Known Planet — StScI
ONG BEFORE our Sun and Earth existence provides tantalizing evidence when Hubble failed to find close-orbiting ever existed, a Jupiter-sized planet that the first planets were formed rapidly, “hot Jupiter”-type planets around the stars formed around a sun-like star. Now, within a billion years of the Big Bang, of the globular cluster 47 Tucanae. Now, L13 billion years later, NASAʼs Hubble leading astronomers to conclude that plan- it seems that astronomers were just look- Space Telescope has precisely measured ets may be very abundant in the universe. ing in the wrong place, and that gas-giant the mass of this farthest and oldest known worlds orbiting at greater distances from planet. The ancient planet has had a The planet now lies in the core of the their stars could be common in globular remarkable history because it has wound ancient globular star cluster M4, located clusters. up in an unlikely, rough neighborhood. It 5,600 light-years away in the summer con- orbits a peculiar pair of burned-out stars in stellation Scorpius. Globular clusters are “Our Hubble measurement offers tan- the crowded core of a globular star cluster. deficient in heavier elements because they talizing evidence that planet formation formed so early in the universe that heavi- processes are quite robust and efficient at The new Hubble findings close a decade er elements had not been cooked up in making use of a small amount of heavier of speculation and debate as to the true abundance in the nuclear furnaces of stars. elements. This implies that planet forma- nature of this ancient world, which takes a Some astronomers have therefore argued tion happened very early in the universe,” century to complete each orbit. The planet that globular clusters cannot contain plan- says Steinn Sigurdsson of Pennsylvania is 2.5 times the mass of Jupiter. Its very ets. This conclusion was bolstered in 1999 State University.
“This is tremendously encour- aging that planets are probably abundant in globular star clus- ters,” says Harvey Richer of the University of British Columbia. He bases this conclusion on the fact that a planet was uncov- ered in such an unlikely place, orbiting two captured stars — a helium white dwarf and a rapidly spinning neutron star — near the crowded core of a globular cluster, where fragile planetary systems tend to be ripped apart due to gravitational interactions with neighboring stars.
The story of this planetʼs dis- covery began in 1988, when the pulsar, called PSR B1620-26, was discovered in M4. It is a neutron star spinning just under 100 times per second and emit- ting regular radio pulses like a lighthouse beam. The white dwarf was quickly found through its effect on the clock-like pul- A rich starry sky fills the view from an ancient gas-giant planet in the core of the globular star sar, as the two stars orbited each cluster M4, as imagined in this artistʼs concept. The 13-billion-year-old planet orbits a helium other twice per year. Sometime white-dwarf star and the millisecond pulsar B1620-26, seen at lower left. The globular cluster later, astronomers noticed further is deficient in heavier elements for making planets, so the existence of such a world implies that irregularities in the pulsar that planet formation may have been quite efficient and common in the early universe. continued on next page 10
continued from previous page implied that a third object was orbiting the be a star or brown dwarf, and must instead the neutron star to “spin-up” and re-awak- others. This new object was suspected to be a planet. en as a millisecond pulsar. Meanwhile, be a planet, but it could also be a brown the planet continued on its leisurely orbit dwarf or a low-mass star. Debate over its The planet has had a rough road over the at a distance of about 2 billion miles from true identity continued through the 1990s. last 13 billion years. When it was born, it the pair (approximately the same distance probably orbited its youthful yellow sun Uranus is from our Sun). Sigurdsson, Richer, and their co-investiga- at approximately the same distance Jupi- tors settled the debate by at last measuring ter is from our Sun. The planet survived It is likely that the planet is a gas giant, the planetʼs actual mass through some blistering ultraviolet radiation, supernova without a solid surface like the Earth. ingenious celestial detective work. They radiation, and shockwaves, which must Because it was formed so early in the life had exquisite Hubble data from the mid- have ravaged the young globular cluster of the universe, it probably doesnʼt have 1990s, taken to study white dwarfs in M4. in a furious firestorm of star birth in its abundant quantities of elements such as Sifting through these observations, they early days. Around the time multi-celled carbon and oxygen. For these reasons, it were able to detect the white dwarf orbit- life appeared on Earth, the planet and star is very improbable the planet would host ing the pulsar and measure its color and were plunging into the core of M4. In this life. Even if life arose on, for example, temperature. Using evolutionary models densely crowded region, the planet and a solid moon orbiting the planet, it is computed by Brad Hansen of the Uni- its sun passed close to an ancient pulsar, unlikely to have survived the intense X- versity of California, Los Angeles, the formed in a supernova when the cluster ray blast that would have accompanied astronomers estimated the white dwarfʼs was young, that had its own stellar com- the spin-up of the pulsar. Regrettably, it mass. This in turn was compared to the panion. In a slow-motion gravitational is unlikely that any civilization witnessed amount of wobble in the pulsarʼs signal, dance, the sun and planet were captured and recorded the dramatic history of this allowing the astronomers to calculate the by the pulsar, whose original companion planet, which began at nearly the begin- tilt of the white dwarfʼs orbit as seen from was ejected into space and lost. The pul- ning of time itself. Earth. When combined with the radio sar, sun, and planet were themselves flung studies of the wobbling pulsar, this critical by gravitational recoil into the less-dense The full team involved in this discovery piece of evidence told them the tilt of the outer regions of the cluster. Eventually, is composed of Brad Hansen (UCLA), planetʼs orbit, too, and so the precise mass as the star aged it ballooned to a red giant Harvey Richer (UBC), Steinn Sigurdsson could at last be known. With a mass of and spilled matter onto the pulsar. The (Penn State), Ingrid Stairs (UBC), and Ste-
only 2.5 Jupiters, the object is too small to momentum carried with this matter caused phen Thorsett (UCSC).
438-5007 438-5007
ISU/TCAA Skyline is waiting for you! for waiting is Skyline ISU/TCAA
Remember...
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TCAA Treasurerʼs Report — June, 2003 — L. Duane Yockey, Treasurer
OPERATING FUND BALANCE – May 31, 2003 - $ 1,182.81
Income
James Stanlaw (dues renewal) - $ 40.00 Gerry Schroeder (dues renewal - $ 40.00
Expenses
Abrams Planetarium (sky calendars) - $ 211.20 Astronomical League (annual dues) - $ 195.50
OPERATING FUND BALANCE – June 30, 2003 - $ 856.11
------OBSERVATORY FUND BALANCE – May 31, 2003 - $ 753.91
Income
Interest (April, May & June) - $ 0.73
Expenses
None $ 0.00
OBSERVATORY FUND BALANCE – June 30, 2003 - $ 754.64
------TOTAL TCAA FUNDS – June 30, 2003 - $ 1,610.75 ------12
The Welcome Mat We have new members! We have new members! Did I mention that we have new members? Please give a warm round of applause to yet more Stanfordians...
Forest and Geraldine Appleton Stanford, 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 observa- tory, 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!!