Occuthubn(Gnewstetter

Occuthubn(gNewstetter

Volume I, Number 3 January, 1975

Edited and Published by X. F, DaBoli at 6 N 106 White Oak Lane, St, Charles, Illinois 60174 U. S. A.

GRAZING OCCULTATION TRACKS IN THE 1975 OCCULTATIDNS OF STARS BY (433) EROS 94 Pierce Rd., Watertown, Mass. 02172, OBSERVER'S HANDBOOK phone 6}7, 926-2678 Or 864-7360. In David It Dunham order to catch the event, it will be flue to an unfortunate error at the necessary to have observers at roughly printer's, the maps of the grazing qc- A map showing Brian Marsden's predic- even intervals across the whole region cu1tation tracks for 1975 were not in- tion for the path of the occultation of uncertginty. Observers are there- cluded in the 1975 Obgeme7"8 Hand- of Kappa Geminorum by Eros across fore urged to contact the above to co- book; the maps which appear are actu- southern Quebec, the northern tip of ordinate plans. ally those for 1974. We hope to pub- New Hainpshlre, and southern Maine is lish the correct maps in the February shown on p. 9 of the January issue of flue to the relatively low a?titude and Journal of the Royal Astronomical So- Sky and Telescope. Another prediction brtght moonlight, naked-eye observa- cietjjof Canada, and to send the maps was conputecf recently by Paul Herget tions will not be sufficient; at least to a interested observers. These at the Minor Ptanet Center at Cimin- smait binoculars or opera g7asses maps will be available early in the natl Observatory, According to Herget. which can be firmly held against a new year; please write to me if you the path is considerably farther post or other solid object will be would like a copy. , southwest, passing near Ottawa, Ontar- needed to make reliable observations. io; Massena, New York; Rutland, Ver- Binoculars and opera glasses are com- John R. Percy mont; and about halfway between Boston mon enough that appeals to the public Editor: Observer's Handbook and Providence, Rhode Island. Clue to fOr observations, via newspapers and R. A. S. C. the prediction uncertainties, it seems television, could be quite productive. 252 College Stmet that the approximately IS-mile-wide Dr. Clark R. Chapmen, Planetary Sci- Toronto ET 1R7, Canada path couTd cross any part of New Eng- ence Institute, 252 1L Ina Rd., Suite land, northern and eastern New York, I). Tucson, Arizona 85704, phone 602, southern Quebec, easternmost Ontario, 297-}176 or 297-4377, is preparing a Bermuda. any of the Caribbean islands suitable press release which will be south and east of the Virgin Islands, distributed when the area to be cover- eastern Venezuela, etc. Thomas Van ed is established. Local and regional Flandem at U.S.N,0. will comte an- coordinators can collect observations, other prediction, Early in January. and are encouraged to do so for obser- the predictions should be reconciled vations by the genera} public, which down to a 150-mile-wide corridor. will be more likely to respond if they Then, mrd will be disseminated to ail can report with a free telephone cali known observers in the areas mentioned than by any other means. Al] reports above and it should be feasible to co- scope,should 49-50-51eventuallyBayreachStateSk kd.,andCam-Tele- ERROR IN PARTIAL ordinate observations along parallel OCCULTATION PREDICTIONS tracks separated by 5 km, as described bridge, Mass. 02138, phone 617, 864- in the last issue. 7360. It should be stressed that nega- David 1L Dunham tive as well as positive observations Two regional coordinators are working are wanted. The observing period for Several partial occultaticms of plan- through the A.A.V.S.O. to help plan observers in eastern Canada to New ets by the moon have been observed us- observations in their areas. They are England should be from 7:)7 to 7:22 ing µredictions comuted with my com- George L. Fortier, M.D., 63 Devon Rd., p.m. Eastern StaRdard Time on Thursday puter program, establishing the accur- Bale d'Urfe. Quebec X9X 2hl7, phone evening, Jan. 23rd. If Eros is visible acy of most of the computed data. How- 514, 457-3533, and Alain C. porter, 10 in your telescope, start recording ever, during preparations for the par- Sea Lea Dr., Narragansett, Rhode Is- when the objects coalesce and stop tial occujtation of Mercury in Octo- land 02882, phone 401, 783-2336. The when Eros is separated from the star ber, I discovered that one of the in- A.L.P.O. Minor Planet Bu1,1,et,'i,n 2, p. again. terpolated points was about 3 miles in 23 gives John Allcock, aWMDuntain error. Observers should watch for pos- St., Montreal, Quebec H3G lz7, phone Dr. Seville Chapman, 94 Harper Rd., sible similar errors by plotting at 514, 844-1694, as a coordinator for Buffalo, n.y. ]4226, phone 716, 839- least four poiRts; if a straight line Quebec, but since he and Fortier are 1999, has designed and constructed q" gentle curve can be drawn through both members of the Montreal Centre of rather inexpensive equipment which can them, they should be accurate enough the R,A.S,C., they are presumably com- record the Kappa Geminorum occultation for prediction purposes. If not, check municating with each other. Dr. Edwin to better than 0501. The crucial item for plotting errors. If one point is B. Weston, 80 Oak St., Lexington, Mas- in this design is a United Technology still out of line, plot two or three sachusetts 02173, phone 617, 862-6148 PIN 3DP photodiode, available for of the uninterpolated points, which or 861-4040, is familiar with astro- $9.65 from [rondequo'it Industries, P. should be accurate. The error is rare nomical resources in Maine and New (I. Box 7637, Rochester, N.Y. 14622, and seems to be due mainly to the in- Hanpshire and is trying to encourage phone 716, 544-6257. Also needed is a terpolation procedure. ljnforturtately, observations there. Local coordinators fie7d effect transistor operational i win not have time to track down and mfght include Prof. Paul Mamet, Dc- anplifier; Dr, Chapman used an $18 correct this error during the next few partement dc Physfque, Universite Burr Brown 3522, but he says that a months, The interpolation procedure Laval, Cite Universftaire, Quebec 10, cheaper Fairchild type 740 could also for the calculation of occultation Quebec (a telephone number is not han- befeedbackused. resistorsSome 22-Metcostohm (oraboutgreater)lOt a- limits for stars is slightly improved dy, but the phone for Gaetan Chevalier, so that the error probably does not another Quebec City R.A.S.C. member, piece) and two 9-volt transistor radio occur with them. is 418, 524-6918) and Dennis di Cicco, batteries are also needed. The output

b_ 20

COuld be recorded with a guod-qua1ity used for visual guiding). Field-test- ing the Sky and Tclescope map. In many tape recorder, Or (more likely) could ing the equipment on Kappa Geminorum of these cases, no occu)tations will be connected to a voitage-controiled before the night of the event will be be visible from the earth's surface, oscillator connected to a small loud a virtual necessity for success. Un- and for some others, Eros will be speaker (a small cassette tape record- fortunately, time is very short; any- brighter (depending on its phase) than er could record the resultant signal; one interested in building the equip- the star, making reliable visual ob- hNV or CKlj should also be recorded}. ment should request plans and parts by servations i@ossible. Without predic- Copies of plans to build the setup are telephone. The United Technology jjho- tions, the chances for any one Observ- available from Seville Chapman, Clark todiode might also be available from er to see an occultation are extremely Chapman, me, and probably the regional distributors in Toronto, Montreal, small, but if enOugh try, perhaps one coordinators listed above (they have Boston, or New York Ctty. The equip- will. If more than one observer In an been sent copies). The design is rath- ment could also be used to obta¶n pho- area tries to see these, they might er simple, so any amateur with a lit- toelectric records of lunar occulta- try to separate at intervals of about tle knowledge of electronics, able to tions, especially with larger (to get 10 miles in an east-west direction to buy the parts, and with a suitable fainter stars) amateur telescopes. increase chances. telescope and recorder, who is plan- ning to attenipt the occuitation of With a horizontal parallax of about Hopefully, the kappa Geminorum event Kappa Geminorwi is encoeraged to do so one minute of arc, it would be remark- will be more successfully observed pbotodectrically. With enough advance able if Kappa Geminorum were to be the than the occultation of a Rh-magni- notice, Seville Chapman has also ex- only star to be occulted as seen from tude star by (129) Antigone predicted pressed a willingness to loan his pro- the earth's surface as Eros careens a- for the southeastern United States totype to a responsible amateur pTan- cross the January sky. Judging from last October Rth. Generally clear piing observations from a location the chart on p. g of the january issue skies prevailed, but low altitude in within the predicted occultation zone of Sky and Telescope, it appears that Texas, a difficult-to-use finding with a 6-inch (or larger) telescope several close approaches to fainter chart, and little advance notice with drive. Dr. Chapman says that the stars might produce occu1tations some- caused problems, Probably over 100 equipent can be used with a small where. These will occur at the follow- tried to observe the event. Only Har- telescope, or even with a telescope ing Univc"f1 Time datesh and hku"$: old Povenmim, observing south of Mi- finder (so the main telescope can be ami, claimed to have seen a possible used for guiding; care must be taken one-second occultation. Unfortunately, to keep the star's light centered on there was nobody observing south of the sensitive part of the photodiode, him to confirm the observation or get which is only about one square mi11i- )i!i';:i::;)!':,i\ig!i:ii'!|i:" an estimate of the diameter of the mer) or half of a firmly mounted involved wiiT be obvious from consult- asteroid. pair of binoculars (the other half

PLANETARY OCCULTATFONS £ichhom and others attenpted the April 28 graze near San Angelo, TX, but failed begin ¢1 -27.64, A "166.56, 08h 26m ET Conducted by Mike Reynolds to see anything. J. Vander Stucken ob- end 0 -32.63. X - 43.33, 12h [)5" ET served the event in Sonora, TX. Dmham Recent Observations reports that his group, which consist- May 25 ed of j. Dunham. C. Smith, D. Stock- begin 0 -30.26, A " 10.73. }6h 53m ET 17 July 1974 - Occultation of Venus by bauer, and T. Webber, attempted the e- end G -35.61, A "]65.80, 20h 25m ET a 6% sunlit moon. Another report has vent near Austin, IX. Dunham noted: been received concerning the total dc- Tantalizing views of the moon and Mer- Further infonnation may be obtained cultat'ion of Venus (See vol I, No. 2 cury were glimpsed by three observers, from Dr. David Dunham, University of for earlier reports). L. Nadeau, Bos- but no useful timings were obtained." Texas at Austin, Austin, iX 78712 USA. ton, m, reports that he easily ob- A detailed account of their expedition served Venus disappear and reappear will be given in the next issue of Qc;- Erratum: In Vol I, No. 2, page 13, with the naked eye, from Washington, cu1tation Newsletter for the benefi t colwm 2, the data given for 8 Ceti DC. of those attenpting the similar occul- are actually for the star 2 Ceti. My tation of Mercury in July 1975. apologies for this; I hope that not 12 October 1974 - Occultation of mag- too many observers were thrown off. I nitude 6.40 star 84 B. Cancri (Z.C. Upcomi ng Planetary 0ccu]tations don't know how I slipped in the data 1281) by the 12th magnitude minor for 2 Ceti instead of B Ceti. planet (]29) Antigone. Ib view of Da- 21 june 1975 - Occultation of Neptune vid Dunham's note, in this issue, to by a 97% sunlit moon. This occultation 1836 Birchwood Road the effect that probably over 100 ob- will occur for Antarctica and the Jacksonville Beach, FL 32250 servers were lnvoived, it would seem southem tip of South America, at ap- gratuitous to mention the few names proximately 23 hours ET. that have come to my attention. FROM THE PUBLISHER There are several other marginal dc- ]6 October 1974 - Occultation of Mer- cultations in the first half of 1975: UntiT now, we have provided copies cf cury by a 2% sunlit moon. The diffi- Vol. I, No. i to all requesters, at no cult observation of this daylight qc- Me rcury: charge. Thus, ail subscriptions, to cultation of Mercury was attempted by date, start with No. 2 or No. 3. Ef- several observers. R. Nolthenius and February )0 fective wIth publication of No. 3, S. Hale, Tucson, AZ, observed the to- begin 0 "39.25, A -151.85, 16h 39m ET back issues will be priced at one tal occultation from Tucson. Noltheni- end ¢) +72.77. A - 60, 36. jgh 48m ET fourth the current price of a oRe-year us reports: "The sight was rather im- $ubscript'len. In the interest of keep- pressive; the moon was a razor-thin, June 9 ing subscriptions current, we eventu- very pale arc extending about 150°, begin 0 "63.90, A " 89.46, 20h 54m ET ally will raise the price of back is- while Mercury could be seen es a end tb "64.54, a - 9.10, 22h 04" ET sues more than one year old sonewhat small, bright 20% crescent, g" in above that level. diameter, near the north Cusp of the Neptune: mom" They recorded timings of 1st The current subscription price is and 2nd contacts. D. Dunham, Austin, March 4 $2.00 (U.S.) per year, sent by first TX, reported on Texas observers at- begin t -45.24, A "102.02, ]5h :!: g class surface mail, or by air mail, teWting the CYCt)t. G. Hayster at- end tb -49.84, a - 70.52, jgh adding the difference in cost. Checks tempted to observe a shallow partial should be made payable to: Occu1tat1ori Newsletter. Address: 0ccultatlon News- occu1tation from the University of March 31 - April 1 Texas, but heat from surrounding beg in (l) -31.62, A - 34.14, 23h 30" EI letter; 6 N 106 ldhite Oak Lane; St. buildings prevented observattpns. Id. end ¢1 -36.44, A +122.33, 03h 02" ET Charles. IL 60174 U. S. A, 21

NEW DOUBLE STARS star have been obtained by sophisti- and brighter. cated modern techniques. The separa- David H. Dunham tion and position angle were determn- 1Ae recently received a cQz'ji of "Cbrior- ed by speckle interferometry by Stach- mcil Occultatioas Of stars by ne The table lists additions and correc- nik et al. and reported at the meeting Moon", Union Ob$ervator? Cl rcuiar No. tions to the University cif Texas dou- of the American Astmnomica1 Society 95., p. 1 92-191 ( 1935). ihis lists 28E ble star list gf 1974 May 9 not listed in Gainesville, Florida, in December, stars whose occultations appeared ab- in previous issues. All c(j®onent$ in- 1974. The magnitude difference was de- normal to South African observers ear- dicated were discovered during occul- termined to be 1.9 using the Austral- ly this century. Several mention step tations. Under column N (new double ian intensity interferometer (see p. events, while most involve gradual star code}, "I" designates a triple ID of the first issue). in agreement fades indicating possibie doubles. star, where orbital elements are a- with the speckle interferometer result Publication of thiS many stars would vailable fOr the two main stars while of 2. Analysis of the photoelectric overwhelm an issue of Occultation the third star is near the secondary. records of the September Dccuitation Newsletter, so they wit I be inciuded The third star's separation and p.a. at Lowell and Table Mountain Observa- in an updated full list to be distrib- are referred to the secondary. A prob- tories should contribute mre informa- uted separately later. we are also able faint star in the Z.C. 3015 sys- tion. waiting for some information on visual tem (A.D.S. 14099) is evident in the doubles from Paul Coteau, but the re- blue channel photoelectric record ob- SAD 76814, listed as a possible double cent French postal strike has delayed tained at Mcoonald Observatory in Aug- last time, is actually a possible this. A considerable effort will be ust. triple. Harold Povenmire notes that 'involved to integrate all of this Data the star has a 10.6-magnitude compan- iRto the University Of Texas list. Although the third star in the i5 Scor- ion 4?7 away in p.a. 62", according to Whether this can be done or not during pii (Z.C. 2290) system was discovered Aitken; the possible cowpanicm noted the next few months will depend in during occultaticms, details about the by D. Sharp was probably much closer part on our funding situation.

NEIA UNIVERSITY OF TEXAS SPECIAL DOUBLE STARS, DATE 1974 DECEMBER 20

SAD ZC M N m HAG2 SEt' PA NIAG3 SEP3 PA3 DATE, DISCOVERER, NOTES

78666 TK9.8 9.80.3 go 1974 Oct. 8, D. Dunham, Austin, TX 97148 TX9.0 9.40.03 341 1974 Oct. g, t. Campbell , Temple Terrace , FL 97168 TK8.8 8.8Ci.l 100 1974 Oct. 9, D. DCnham. Liberty HiTT, TX 97429 }198 T K 7.0 7.0 {}.2 130 1974 Dec. 3, hi. Eichhom, San Angelo, TX ?46239 3326 P V 6.7 7.8 0.065 254 1974 Sep. 29, D. Evans, McOonaid Observatory, TX ]63645 2995 G V 6.6 7.4 0.1 150 7974 Noy. 20, T. Campbell, Vema, FL 163688 TV9.510.20.3 236 1974 Nov. 20, R. Noithenius, Tucson, AZ 163771 3015 P I 5.8 6.3 0.257 9.3 .052 264 3rd* )974 Aug 30, J. Africano, Mc[bna1d Observatory, TX 184014 2290 V L 3.0 5.0 0.00001 4.9 0.18 ?70 3rd*: 1974, Stachnik, Gezari, et al.

HIGH ALTITUDE AIRCRAFT PHOTOS FOR RECONNAISSANCE USE

Karl Simms

Besides the space photos available MORE ON OBSERVING REAPPEARANCES SOME CONENTS ON OBSERVING from the EROS data center (see p. IB of' the last issue), the fdlowing a- In response tg our request in the last Amateur teiesctjpe makers ponder wheth- gencies supply aerial photcs that may issue, we have received the following er to build compact, close-to-the- be useful when only old edition topo- coments from Bruce Blunde11, Manhas- ground instruments which children can graphic maps are available: set, ny: use without ladders, or add a few in- ches, to gain better seeing. 0b$erva- 1. U, S. Dept. of Agriculture "I have found that, for reappearances ttjry designers debate puttMg the tel- Soil Conservation Service on the dark limb with the dark limb escope at second flOOr or higher lev- liyattsvi11e, MD 20782 invisible, I have a tendency to watch el. All of us would like muntaintop for the star too far out; it reappears seeing COnditions, with back yard Con- 2. (West coast) ASCS-USDA a little closer to the lighted portion venience. Edward C. Hetherbee, Hamden. 2505 Parley's Way than I had expected. Also, when esti- CT, gives emphasis to this theme: Salt Lake City, UT 84109 mating the C.A. of reappearance, I have a tendency to watch for the star "The article entitled 'The Remote Ocu- (East coast) ASCS-USDA at too high a cusp angle; it reappears lar Technique' especially interested 45 S. French Broad Ave. a little closer to the cusp than I had lie because I use ft most of the time, Asheville, NG 28801 expected. In the critical moments be- especially on the fainter stars. I fore reappearance, an observer should have an 8" f/6 reflector, and for most 3. Cartographic Archives Div. make sure that he does not fail victim occultations, I use a ]6.3 m eyepiece General Services Div. to either of these tendencies. (75X). I find that I can follow d star Katioria1 Archives arid RecOrds Serv. much more comfortably by using this Washington, DC 20408 "While waiting for a dark limb reap- technique. It is useful because the pearance with a crescent moon, with eye Is not subjected to the full light 4. Cartographic Division the crescent at the edge of the field, of the moon until it is necessary, USGS one Should not focus on the moon. This during the actual graze. Washington, DC 20242 is especia11y true if the eyepiece does not have a very flat field, sUch "At my home location, I am less than 2 When writing, specify what areas you as a wide-angle Ke11ner, While the miles from Long Island Sound, and at would like photos for. Coverage charts moon at the edge of the field may be 70 feet elevaticm Even with the best for each state are available. We have in focus, a star reappearing in the seeing conditions, I find that I can- found that the index photos available center will not. Thus the star might not see 8th munftude stars due to the for $3.00 a sheet are the most usefu7, reappear invisible. or at best, might glare surrounding the moon. I believe at the lowest price. These photos are not be noticed until too late. It is that thiS glare is caused by high hu- about one yard square, and cover from best to focus cm the moon (or better midity at my location, I have observed 4 to 10 7 1/2-minute quadrangles. A- yet, a star) while in the center of a grazing occultation of an 8.3 magni- gencies 1 to 3 supply index photos. A- the field, and ignore the (jut-of-focus tude star at a location 15 miles in- gency 3 oRly supplies photos taken be- crescent at the edge of the field land and at 300 feet elevation with no fore 1943, while waiting for reappearance." glare problem at all." 22

1973 TOTAL OCC1)LTATI{)N TALLY Non Rank Observer VaTue Total R's ZC David "m Dunham 1 N. Wieth-knudsen, Tisvi7de7unde, Denmark 426.08 210 98 739 hie fn11owing tally of total occulta- 2 Robert Hays, Chicago, TL 365.68 240 57 163 tions for 1973 has heen compiled from 3 joe] Dubin, Skokie,lL 315.37 ISO 75 113 data reported in the returned observer 4 Harry Cochran, Brownwood, TX 263,81 169 43 120 iM'ormdticn forms distributed last 5 David Dunham. Austin, TX 229.?4 77 69 48 3uly aRd from copies of reports sent 6 M. D. Overbeek, Johannesburg, South Africa# 170.30 124 21 78 to the University of Texas. The com- 7 John phetps, Calumet Park, It- 165.5} )17 22 82 pleteness of the list can be judged by 8 JOhn Korirttus, Palm Bay, FL 152.15 86 30 0 the fact that the overall total is 9 A. Morrisby, Causeway, Rhodesia 748.97 74 34 52 3448, in comparison with about 6200 IQ Ernesto Calpo, Quezon City, philippines* 139.33 82 26 24 timings made during 1973 reported to ii clay Sherrod, North Little Rock, AR 114.46 88 12 29 H.M.N.A.O. at the Royal Greenwich Ob- 12 Richard Nolthenius, Tucson, AZ 109.30 63 21 37 servatory. About 300 of the timings 13 Nicholas Esyjsito, New Hyde Park, NY 103.30 57 21 0 reported here are known to have not 14 Steven Griffith, San Antonio, TX 99.48 62 17 38 yet been reported to H.E.N.A.O., while 15 H. F. DaBo71, St. Charles, IL 92.89 51 ]9 23 H.|'!.N.A.0. includes approximately ROD ]6 Bill Fisher, Colfax, CA 90.48 53 17 17 timings made during grazing occulta- 17 Robert Bailey, Houston, TX 90.10 46 20 29 lions excluded here. Hence, the list 18 Robert Sandy, Kansas City, MO 89.48 52 17 IS is about 3/4 complete. 1Jnfortunate?y, 19 j. Pogoda, Olomouc, Czechoslovakia 69.23 56 6 45 some observers, including a couple 20 James Fox, Cottage Grove, MN 57.64 40 8 27 with rather large totals, could not be 21 Charles Cobb, McOona1d Observatory, TX# 56.00 56 El) 48 included because they hadn't kept ac- 22 Clifford Bader, west Chester, PA 51.23 38 6 5 curate records Of what they had re- 23 Richard Van Etten, Brandon, FL 50.66 22 ]3 t) ported to H.M.N.A.O. 24 JosC OsOrio, Vi7a Nova [le Gala, Portuga? 50.61 44 3 26 25 Luciano Pazzi, Noycedaje, South Africa 48.84 29 g 7 Don Stockbauer wrote the computer pro- 26 Mike Reynolds, jacksonville Beach, FI. 48.43 33 7 19 gram which produced the list, and key- 27 Robert Germann, Wald, Switzerland 45.82 37 4 1 punched most of the data; Scott Kel- 28 Per Darnell, Rodovre, Denmark 42.82 34 4 18 be)} did some of the keypunchinp. The , 29 David Evans, McOonald Observatory, TX# 42.00 42 0 36 program coMjutes a "value" which is 30 Mike Lawson, Austin, IX 40.84 21 9 4 3.20 times the number of reappearances 31 Klaus Klebert, Stuttgart, West Germany 40.00 40 0 25 plus the number of disappearances; ob- 32 1AiT1iam Sandmann, McOonald Observatory, TX# 40.00 40 0 34 servers are ranked according to their 33 %ug?as Kali, Leicester, Eng7and 39.6} 33 3 10 "value". 3.20 is the ratio of the 34 Geoffrey Kirby, hleymuth, Dorset, England 39.02 28 5 11 total number of disappearances to the 35 John West, Bryan, TX 37.64 20 8 14 total number of reappearances, applied 36 John McGraw, Tonantzintla, Fkxico# 37.00 37 0 24 to reflect the increased value of re- 37 Francisco Diego, Mexico City, Mexico 35,43 20 7 9 appearances in anaiyses of occultation 38 James McMahon, China Lake, CA 35.41 31 2 18 observations due to the uneven distri- 39 Rick Binzei, Washington C. H., OH 33.43 IB 7 2 bution of observations. It has been 40 Donald Scott, Panama City, FI- 32.05 JO 10 3 suggested that this be carried further 4] Paul Goodwin, Shreveport, LA 31.20 29 1 15 by sunning the U.S.N.O. value codes 42 Harold povenmirm Indian Hdrbour Beach, FL 31.02 20 5 7 for each observed event, but this was 43 Haruki Abe, Yamakoshigun, japan 30.82 22 4 7 not done, due in part to the fact that 44 Vic Matchett, Indooroopiiy, QueerlslaRd, Australia 30.00 30 0 21 a few of the listed observers do not 45 Mickey Schmidt, Ira, TY 29.41 25 2 1 have U.S.N.O. predictions, but mainly 46 Mervyn Jones, Maryborough, Queensland, Australia 28.00 28 0 IQ because it would be a much biqger job. 47 Steve Vcigt, McOonald Observatory, TX# 28.00 28 0 24 48 Keith Home, Claremont, CA 27.61 2) 3 17 FO11owing the observer's name is the 48 Simon M¢Mi7?an. l!o71and Park, Queensland, Australia 27.00 27 0 13 city, then state (using the 2-tetter 50 William Westbrooke, San Francisco, CA 26.82 ?8 4 4 abbreviations), province, Or country, 51 Namer and Swasey Observatory, East Cleveland, OK 26.61 20 3 0 where most of the observations were 52 Harald Marx, Mijnchingen, West Germany 26.20 24 1 }8 made. An asterisk (*) indicates that 53 P, Hazucha, H?ohovec, Czechoslovakia 24.00 24 Q 7 rnore than one observer is included in 54 Roger Tuthill, Mountainside, NJ 23.82 15 4 0 the totals, while a space sign (#) in- 55 Bradley Timerson, Newark, Nj 23.82 15 4 8 dicates that at least some (usually 56 Thomas Canpbe11, Temp7e Terrace, Ft 23.61 17 3 9 all) of the observations were made 57 John Church, Princeton Junction, NJ 23.61 17 3 5 photoe}ectrica11y. After the "value" 58 dan Hers, Randburg, South Africa 23.20 21 1 7 and the total number of reported e- 59 Lee Mills, Austin, TX 23.00 23 0 7 vents is given the number of reappear- 60 S. Kochan, Ziar N. Hroriom, Czechos1ovakia 22.20 20 1 2 ances and the number of' the total 61 George Haysler, Austin, TX 21.61 15 3 g which are not Z.C. stars (the U.S.N.O. 62 Clyde Reid, Se?kirk, Nanitoba, Canada 20.00 20 0 0 reference number of Z.C, stars has no 63 Mary King, Amda)e, Nova Scotia, Canada 19.82 17 4 0 "2" prefixed in the U.5.N.0. predic- 64 Herbert Luft, Oakland Gardens, NY 19.41 15 2 2 tions). 65 P. Vozar, Banska Bystrica, Czechoslovakia 19.20 17 1 3 66 Michae7 Wilson, Milwaukee, HI }7.41 13 2 0 It is interesting to note that the top 67 H. j. kliddop, Pierrefonds, Cluebec, Canada 17.20 ]5 3 C· three observers live in areas which 68 Alfred Webber, Chadds Ford, 'PA 17.00 17 G 1 are not known for clear skies. It 69 Roy Bishop, Avonport, Nova Scotia, Canada 16.82 8 4 g shows what can be done with the de- 70 Jeri Jones, Salisbury, NG 16.61 10 3 0 tailed U.S.N.Q. predictions, experi- 71 George Fortier, Bale d'Urfe, Quebec, Canada 15.00 15 0 5 ence, aM persistence in taking advan- 72 Danie) Green, Boone, NG 14.61 8 3 4 tage of the clear nights which do oc- 73 Ronald Parmentier, Green Bay, Nl 14.20 12 i 2 cur. Roberts Hays uses a 20-cm Celes- 74 vojtisek, Prague, Czechoslovakia ]·4.00 14 t) 6 tron, while joel Dubin uses a IS-cm 75 Wayne Clark, St. Louis, MO 13,41 9 2 4 reflector. Nobody has come close, how- 76 T. Pertile, Ostrava, Czechoslovakia 13.00 13 D 0 ever, to the record 462 timiAgs made 77 Carroll Evans, China Lake, CA 12,00 12 0 8 by Robert Chew with a 32-cm reflector 78 Cliff Turk, Pinelands, South Africa 1].20 9 1 0 in California in 7966 (before 1'.S.N.O. 79 Timothy Chambers, Redding, CA ]0.61 4 3 0 predictions). 80 Alvin R. Flesher, Baltimore, MD 10.20 8 1 6 81 James Dominy, Austin, TX ]0.20 8 1 2 A coupon is enclosed to report the 82 J. Scilheim, Tromsoe, Norway }0.0(1 )0 0 0 ?3

:iumher of 0ccu?tati'm timing', :7ac!c NCR durinc.i 197'1. 1\ list gf 1974 Lntal';. Rank Observer Value Tot.a1 R' S 2C ba'ied uonn returned c:nupnns, and any c(j[)jcs of cccn1tation titninq r{"ngrts m ,1. 1)c:enas. Hratislava Krasnany, Czechoslovakia 9.41 5 2 G rc'i:t'i vt·d, w'I 11 bp pnhl i",hrd, nr'nh,zh1v M Alain PorLrr, Narragansett, RI '9.20 7 I 3 ii, jt)(· .Iulv, |'J'7'; isSur Nr inuld 1J·,f' 8!x P. Na.i ';pr, Prmiut' , Czt'thos iovaki a g.m g t) 7 I'.M.N.AJ). ". n|r,rrv,jlinn 1ile·'. ('|3.1.N. 116 I el 1)uU:hlm'r, l¶c.Dnnald Qbservatorv, m Q.(K) ') (t / n , n'c' l' t Ur ': l op i c'r nrl Ina ([nr I. i l |.ijjl0' ) $1/ Charli'r Kapal . Part in. NJ 11.41 4 I) for i }jjq jwT"$)Dsc". btit t}:r',r ctn nnt. 88 ,1. Kl inlf'sova , Rrno , Czechos jovak la Et.7n (, I ¢;Q?1t,lin unique observer identifica- 89 Ft. Mckinnon, Panama City, FL 8.00 8 t) ? tion, although this is im:?uded on 90 M. Sedlacek, Uhersky Brod, Czechoslovakia 7.41 3 2 i) their repo"t forms (they may add this 91 William Dickinson, Norfolk, VA 7.41 3 ? 0 informatioR later) . Since most observ- 92 Jean Meeus, Erps-kwerps , Bel gi um 7.20 5 I 0 7 ers make timings from one place. where 93 Richard Sweetsir, Jacksonville, FL 7.20 5 } P others do nnt observe, someone could 94 Hilly Verhaegen, :'etteren, Belgium 7.00 7 0 I crass-reference H.M.N.A.O.'S fi7e for 95 Robert Pike, Mississauga, Ontario, canada 6.20 4 I 2 a year with U.S.N.O.'s records, to 96 J. Lacny, Ziar N. Hronom, Czechoslovakia 6.00 6 0 0 make a fairly comprehensive list, but 97 Ronald Cross, Christchurch, New Zealand 6.00 6 0 2 thiS would involve Quite a bit tjjf work 98 Edward Wetherbee, Hamden , CT 6.00 6 0 2 which could probably only be done by 99 Victor Slabinski, Arlington, VA 6.00 6 0 3 an amateur in the Washington, D.C. 100 ft Hartansky, Banska Bystrica, Czechoslovakia 5.20 3 1 1 area. For 1974, it will be most effi- 101 B. Shim, Winnipeg, Manitoba, Canada 5.00 5 0 0 cient to use the enclosed coupon. 102 J. Smudla, Gottwaldov, Czechoslovakia 5.00 5 0 0 193 Standovsky, Prague, Czechoslovakia :7 5.00 5 0 i 104 Luigi Baldine11i , Bo?ogna, Italy 5.00 5 0 105 Kevin Kane, Columbus , OH SOME MISCELLANEOUS ITEMS 5.00 5 0 0 106 Karl Simms, Jacksonville, FL 4.20 2 1 7 107 k. jehlicka, Brno, Czechoslovakia David H. DunhalR 4.00 ¢ 0 0 108 Chromek, Banska Bystri ca, Czechoslovakia a.ocl 4 0 4 109 Fabricus, Banska Bystrica, Czechoslovakia 4.00 4 a few observers who used to scAd cop- D 3 no Si rova, Prague , Czechoslovakia ies of graze reports to H.M.N,A.0. 4.00 4 0 1 III Roy Caputo, Howard Beach, NY have stopped doing so due to the an- 4.00 4 0 0 112 Richard Wade, salt Lake City, Utah 4.00 4 nounced intention of keypunching the 0 2 i] 3 Bohumii Malacek, Valasske Mezirici , Czechoslovakia 3.20 1 data at the University of Texas and i 0 114 F. Pavlas, Holesov, Czechoslovakia 3.20 I sending HJI.N.A.Q. data converted to } 1 V. Skodova, Valasske Mezirici, Czechoslovakia their format. Unfortunately, this pro- ]15 3.20 1 I 0 716 Byron Labadie, Tulsa, OK ject has been delayed, but hopefully, 3.20 1 7 T Hank Geerlof, Calgary, Alberta, Canada will be started during the next few 117 3.00 3 e 0 1[8 K. Vanek, ·01omouc, Czechoslovakia months. Even when it is begun, H.M.N. 3.00 3 0 2 119 J. Teply. Broumov, Czechoslovakia I} A.0. should still have a copy of the 3.00 3 0 120 0. Kolar, Gottwaldov, Czechoslovakia t) report, even though on a University of 3.00 3 Cl 12) Sed1 acek, Hlohovec. Czechoslovaki a t) Texas form, in order to check for pos- 3.00 3 0 122 j. Robert Andress , Hiram OK sible keypunch errors and observer 3.00 3 0 0 123 Robert C3 yde. Streetsboro, OK 3.00 3 0 0 coments. 124 Robert Yajko, West Leechburg. PA 3.00 3 0 0 725 m. Week, Ostrava, Czechoslovakia 2.00 2 2 \AdV is available by telephone at Berg- Q 126 Paika, Prague , Czechoslovakia 2.00 2 strom A.r.g., Austin, Texds. Call SR, 0 1 ]27 Krejci , Prague, Czechostovakia 2.QQ 2 0 1 385-4100 and ask for extension 3303. 128 M. Tonomura. Shizuoka-ken. Japan 2.00 2 0 As mentioned on p. 7 of 0,G.O.-VIII, 0 129 Michael Kazmierczak, Atlantic Beach, FL 2.00 2 0 7 accurate time is also available by 130 Bruce B]unde11, Manhasset, NY 2.00 2 0 0 telephone in New York City; Chicago; 131 Michael Blair, Washington C. H., OH 2.00 2 0 Fairbanks, Alaska; Boulder, Colorado; 0 132 M. '!0nasek, ?0kycany , Czechoslovakia 1.00 1 0 0 Kehaha, Hawaii; the United Kingdom; ]33 M. Neubauer, Valasske Mezirici , Czechoslovakia 7 ,00 I 0 and some European countries. WWV might 0 -134 S. Pinter, Hurbanovo , Czechoslovakia also be available b,y telephone at a T.00 1 0 Q 135 P. Kastovsky, Val asske Mezi ric'i , Czechoslovakia 1.00 I United States military installation 0 0 136 T. Metelka, l'hersky Brod, Czechoslovakia 1.00 I near you; if so, let me Know, and I'll JJ 0 137 B. Lukac, Kurbanovo, Czechoslovaki a 1.00 1 spread the word. D 0 138 P. Saroch, Slany, Czechosjovakia 1.00 I ·3 t) 139 Mudra, Prague, Czechoslovaki a According to the National Bureau of ].00 I t) 1 ]40 CsoTte, Hurbanovo, Czechoslovakia Standards Time and Frequency Service 1.00 1 S Q 141 pajt1 , Rokyany, Czechoslovakia Bulletin No. 204 (Nov. 1974), p. 7, 1.00 I 9 C the radiated power Of KMVH will remain 142 jezik, Hiohovec, Czechoslovaki a 1.00 I 0 C unchanged for the present, due to a 143 M. Jirku, Jindrichuv Hradec, Czechoslovakia 1.00 1 0 0 144 large number of responses objecting to DougTas Sharpe, Satellite Beach, FL 1.00 1 0 0 Claude Baines, Rest Monroe, LA the proposed reduction (see last is- 145 ).00 1 0 0 sue, p. 17). 146 James Bryan, Austin, TX ].00 1 0 0 147 Stan Harley, Austin, TX 1.00 1 0 I 57AL00 3448 T69 My fundinC situation, as described in RID value ratio = 3.20 m the last issue, p. 17, remains unchanged. The grants which will deter- mine my future (if any) at the Univer- Richard Nolthenius has recomended an forced agreement with timings made at sity of Texas will not be decided un- extension of the extended H.M.N.A.O. neighboring stations. For examo1e, If til january; at least, they have not timing method code described in O.G. an observer at station 2 recorded his been rejected yet (mid-'ecember). Two O.-VIII, p. 3. Add method number 16 - events, but the short wave time si'g- new computors have become operational, Estimated time with respect to art ac- naZs {even the minute marks, calls of and more win ]ike1y follow. The Janu- curately timed event. This might be , other observers, or passing automo- ary - March, 7975 cjraze credictions, needed, for example, when twO or more biles) were too weak to rec:md, and exceot for a few soecia1 requests, all events occur so quickly during a graze the observer at station 1 timed the have been cQwutM by others, at dis- that the observer can't record them first disappearance 2.9 seconds later tant institutions, fOr the "irst time. separately, but did call Out the first than the observer at station 3, the I? is 1ike?y that, dvring the next few event and can recalt essentially what time of first disappearance at scation months, we can comCmts ill of t'ne 1975 happened after that. I pmpcjse another 2 is known to ± 1.0 second, if the ob- predictions, and develop z yea"'5 lead method, number )7 - Relative timings servers were set up a1cmC a straight time. made absolute to the given accuracy by road. 24

CRP.Zi:S 1)FiSf RVG) IK 19/4 Iii F01tT1)I TL) double or |||ulti|})e systems separately) frnm hi', !i,jc'k Yard tiljrirq Vic t"ast TIIF llNl'/['!tSl1Y (ii' ft :t,v: ill Uric night"? right Yr',1."s (mull ip1p events wert' tit"- ed during fwtl of thtm). f;ijviil Iii, |)ij|1'kii', Robert Candy points OUt that the ),jti- t.llriC libration increasM 3?3. rather Ths' iwterisk t*) in tho entrv for TKO '?:·;jnrt'. I,! 1'!74 c·XPr·'|i! inn'. ·1·,|. I iqted thim 2':5. as stated on line 32, col. (ktOf't'r ?1St Qraze qC Xi Saqi ttarii j'b prE'v);)|j': js4ljps arr' I i":!.cr1 ht·rr in I. i'. 15 of the last iSSijf. Incident- (7.(. .?759} fg mcrrlv tn ui11 atti'n- the 4a's8' fsr¶ld7. Thr 1ii;t 'rh' months ,i1ly, he observed the grazes of Octo- tiQR to the nnssil'ilitv t¶at the :jrn- have Seen very productive, ',ci; i) four ber Qth dhCj 23rd from his home, makim diction basis Mab' not hi? comarat'k exi'eC4icms obtaining more t.iminqs three arazes which he has observed with that used in the tlnited ¶!.atps. than any of the expeditions for grazes of distant stars listed in the previous two issues. September had the most expediticms, 23, not includinC twc successful expeditions for the Delta Scorpii Craze {unfortunately, clouds interfered considerabZy for the group a: Gila Bend, Arizona, and also partly for the Baja Caiiforjifa effort; five ether major attempts were c0mp)etetv 1974 Star % # g' C Ap couded out} . Ito. 2l Number Mag Sn1 .C.A. Location Sta ,T,m, G £m_ Organizer ,S.t, Wei, §

The Kovember 20th graze of 27 G. Cap- 8 1 2797 3.0 96+ 7S Key Largo, EL 1 5 15 Harold Povenmi re C ric.:jrni (Z.C. 2995) Ohserwd in Flori- 8 ID Z02028 7.7 57- 7N Scottsmoor, Ft 2 9 ]5 Harold Povenmim da is now the sixth most successfully 8 23 Z13928 8.4 37" N Micheiago,Austr1. 'I 4 6 10 David Herald C observed graze, with a total of 136 8 30 3015 5.3 94+ 23S Jupiter, FL 1 }0 15 Harold Povenmire timings. A good profile and the star's @cxpected duplicity helped. Since the 9 8 Z02960 7. 8 66- N Salisbury, Rhod. I 5 7 13 A. Morrisby qraze occurred a couple (if minutes 9 10 ZQ5183 9.0 40- 3N Sabino Can., AZ 1 i 6 15 R. Nolthenius 9N358 2CJ Ear"7ier at Verna than at CKna, Camp- g ii 206694 8.0 29- 4N Hinter Beach, FL I 1 15 Harold Povenmire bell was the fi rst to see the coman- g 11 Z06883 8.3 27- -3N Tucson, AZ 2 2 9 }5 R. Nolthenius C20N 1 35 tor.. .However, Pqvenmire's res'jlts were g )2 Z08055 8.7 18- 4S Satellite Bch, PL 1 1 41 Harold povenmire meded ir: Order to estimate the sepa- 9 12 Z08070 7.7 18- 3N Tucson, AZ 3 19 8 ]5 R. Nolthenius C16N359 48 ration. 9 21 2419 8.[ 37+ S Racepond, GA 1 7 4 20 Richard Sweetsir 9 22 2430 7.0 38" 9S Rose Cmek, 1¶\1 2 7 7 11 james Fox 55167 6 Another "tau dozen" graze which should 9 23 217340 8.3 48+ 13S Rossvi11e, KS 3 9 4 20 Richard Wilds 166 -S have been included on last issue's g 23 Z17340 8.3 48+ 13S POrt Wash., WI 16 56 8 IS Robert James 55166 -8 list was one which tied For 7th (now 9 25 2854 7. 3 67+ 18S Arcadia, FL i 8 6 20 Thomas Campbell 15162-36 8th) place wi th ) 34 timings. It occur- 9 27 Z22769 8.5 85+ 18S Sahuarita, AZ I 11 5 ]5 R. Nijlthenius 8N?66-56 red on 1971 September 24 involving 153 9 29 3320 5.3 95+ ?65 Leon Smngs, tx 1 3 7 ?5 Steven Griffith 173-59 B. Librae at Arthur's View, South Af- 9 29 3320 5.3 95+ 16S Creedmore, TX ii 33 7 25 David Dunham 10N173-59 rica; the expedition was organized by 9 29 3340 7.5 95+ 165 Liberty Hill, TX 1 i 4 25 David Dunham 35172-65 jan Hers. Multiple events involving 9 30 3453 4.9 98+ 3QS Daytona Beach, FL 3 6 8 15 Michael Reynolds a}] three components helped make it 9 30 3455 6.4 98+ 31S Liberty Hill, TX 3 6 6 25 Don Stockbauer 6N]64-61 the most successful expedi tion outside the United States. The November 18th IQ 9 Z07678 9.0 43- 35 Kansas City, MO I 1715 Robert Sandy 783 48 expedition for 36 Sagittarii (Z.C. JO 9 Z07710 8.8 43- 3S Liberty Hill, TX 2 5 4 25 Don Stockbauer 15187 46 2757) is now the I4th most successful. IQ 10 Z08803 8.7 31- 8S Williams Bay, WI 1 4 6 ]5 Homer DaBo}1 15187 59 The largest number of successfu? sta- 10 13 1410 5.3 23- N Maytown, FI. 2 8 815 Richard Sweetsir Z'Qns for a graze this year, at POrt 10 IT 209719 7,8 2?- 6S AtO1 id, CA 4 ?6 10 Robert Fischer 15183 65 Hashington on September 23rd, used the ]0 12 Z10378 8.1 12- 8S Cooper City, FL 3 16 ]5 Harold Povenmire Mwaukee Astronomical Society's tim- 10 20 26}4 6.2 29+ S B1oemfontein,$.Af. 2 ]9 S 8 Graeme Walker inq cable arid many of their special 10 21 Z18492 8.0 31+ 13S Four Comers, CA 110 7 25 Keith Home 10:1Rch graze telescopes. 10 2? 2759 3,6 36" 9S Hayiing, Hants, UK 3 10 9 5 G. J. Kirby 75*'69-27 10 23 Z21199 8.3 50+ I3S Kansas City, MO 3 14825 Robert Sandy 9'1165-¢3 The September 29th graze of Situla to 23 3008 6.9 55+ ]1S Little Bredy, UK 2 1511 G. J. Kirby - 169-48 (Kappa Aquarii , Z.C. 3320) helped de- to 27 224663 8.8 85+ 175 Tucson, AZ 1 14]5 Richard Nolthenius ]69-E? fine the unusually low area cjf the mon at negative 1ibrations in the I] 3 0847 3.0 86- IDS Rice Lake, FN 1 1 8 20 Janes Fox 793 22 range 165' - 175° of Watts amie (this 11 4 0969 7.1 80- 5N Picacho, AZ 7 i 6 15 R. Nolthenius 23N353 32 area, incidentally, is one of the f& 11 5 1}24 6.9 69- 4S Shreveport, LA 3 IQ 15 Paul GOOdwin ' dreas not photoqraohed by lunar Orbit- )7 8Z10))7 8.136- S Qrmnd Beach, FI. 2107 75 Karl Sinmns ers). Apjjropri ate correcti ons were ii 9 Z10861 8.2 24- 9S Hart1and, TL 2 )1 715 Homer DaBoT1 85185 71 "sent to all profile plotters. As a }1 9 Z1086] 8.2 24- 9S Goshen, IN i 2 8]5 Rick Binze1 consequence, the large shifts observed 11 10 ]743 6.8 }5- N Cat Mountain, AZ I 2 8 75 Richard Nolthenius in this area elf the mon were rather 13 18 2757 5.1 16+ RS 01ancha, CA 15 86 Janes McMahon $uccessfu71y prEdicted. A notable ex- 11 20 2995 6.2 32+ 14S Verna, FI 2 25 9 20 Thomas Campbell )63-53 atmle was Z.C. 2995, where a south 11 20 2995 6.2 32+ 145 Cocoa. EL 14 Ill Harold Povenmire shift of 0:9, due to a calculated star I] 22 Z23698 7.9 SI" llS Garnett, KS 1 14 JO Richard Wilds DositioR error ccmplicated the predic- I] 22 Z23698 7.9 51+ 115 Freeman , K) 417 715 Robert Sandy 12N170-64 tion. I} 23 3340 7.5 60+ 165 Edgevi1 le, FL Ill 820 Thomas Campbe17 11 23 3453 4.9 68+ 5S Hayling, Hants, UK 2 4 9 5 G. Nash C 176-62 Texans observed two grazes in one ]1 23 3453 4,9 68+ 5S Bournemouth , UK 3 4 5 9 D. Miles C 776-62 night twice, on 'September 29th and ""DecCmber 6th. The 1¶ter pal r was most 12 4 1359 5.1 72- 95 Cass, MO 112 720 John phelps 0 193 C: interesting, since 2 40" and 100 " }2 6 1582 6.3 SO- IS Tubae, AZ 2 2 8 15 Richard Nolthenius miles of interstate highway separated 12 6 1582 6.3 50- 4S Turnersvi11e, TX 315820 David Dunham 3N186 70 the events. A correction to the pre- R 6 1590 6.9 49- IDS Eddy, TX 319820 David Dunham 4N189 71 diction 'fOr the 2nd graze was computed R 7 Z11388 8.5 38- Tis F]ag1er Beach, FL 1 2 15 Harold Povenmire enroute, besed on results for the lst 12 11 2212 6.1 4- -N Phejan , CA 2 4 913 Keith Home one, Has anyone tried to observe three 72 17 3070 6.6 16+ 95 Hug% NN 1 3 5 20 James Fox 25}67-55 grazes (not counting components of 12 18 Z22541 8.8 17" 9S Austin, IX 4]1531 Don Stockbauer 5166 t

SUME RECENT P1JBLISHLI) This can't compete with U.S.N.O. limb, a reasonable assunption for 'id'E RS ABOL'1 9CCULTATJONS predictions, but the procedure is such a star. instructive and might be of interest comiled :;y i)avid kl Dunham tc those with access to HP-65 calcu- G. E. Taylor, "Planetary Occultations: lators. A Review of the Methods of Predic- T. E. P.e11, "Fireworbr in Your [.ye- tion, the Results of Astrometric A- piece" , in The Great EBCc7pc , edi ted j. 1. 14cGraw, D. 4L Dunham, D. S. Ev- nalysis and the Future Prospects", by M. S. Veils?. t). 11? (Bantam, ?974). ans, and T. J. Moffett, "Occulta- N.A.O. Technical Note No. 34. Occu)- For rtovicEs, this i'. a good brief tions of the PIeiades; 7hotoelectric tations of stars by planets, minor description of the basics of "graz- observations at Tcmantzintla with a planets, and natural satellites are inC' which coRvcys the excitement discussioE of the duplicity of At- predicted since observations can irwcWed. J.S.N.3. is incorrectly las", Astron. J. 79., 1299. Twenty- provide valuable information about gib'en as the address to write for three photoelectric traces, among the sizes, shapes, and atmospheres graze informatim, but any requests the best ever made in visible (if any) of these bodies. Observa- will Sc forwarded to the proper ad- light, were recorded using the 40- tions which have been made to date cress. inch reflector of the National Ob- are sunnarized. He explains that the servatory of Mexico and portable diameter of Ganymede determined by I). bt Dunham, S. It Killen, and T, L. electronic equipment on 1973 Febru- Ristenpart from observatiops of an 3oone, "The Diameter of (I) Ceres ary 11. Close com)onents of SAD occultation in 1911 are ermnecus from a Lunar Occultation", Bull. Am. 76103, 76192, 76225, and Atlas were since the star was too faint rela- Astron. Soc. 6, 432. The first known resolved. The spectroscopic orbit of tive to Ganymede for reliable visual observations Of an occultation of a Atlas is discussed in light of this observations. minor planet by the moon were re- and other photoelectric occultation corded by five visual observers in records of the star. T. C. Van F]andem, "An Investigation Australia on 1973 Sept. 4. The diam- of Possible Systematit Error in the eter calculated from the observed C. L. Mcjrbey, "Distortion Mechanisms Observed Rate of Change of G", gujj, durations of fading is 1200 ± 250 for Lunar Occultation Diffraction Am. Astron . Soc. 6 , 431 . Enprove: km, consistent with modem poTari- Patterns", Astron. J. 79, 1304. Rel- ments resulting from the removal of metric and radiometric results and ative magnitudes of thC"factors problems with a numerical integra- disagrcciM with micrometer measure- causing distortion of photoe?ectric tion, rEcent]y measured systematic ments. Uncertainties in visual lunar occultation observations are corrections to the FK4 system, re- thresholds and lunar slopes are the conpaned on theoretical grounds. moval of periodic terms in the re- train error sources. These could have siduals whose causes could be deter- been reduced by photoelectric obser- G. Ricker, A. Scheepmaker, S. Ryckman, mined, and additiona7 observations vations, but such attempts for this P. Downey, j. Doty, J. Bd11intine. (mostly recent, through 1974 Oct., event were all defected by clouds. and \L Lewin, "High Energy X-Ray Ob- photoelectric data from XcDonald Ob- servation of a Lunar Occultation of servatory) have nsulted in a value 3. L. Elliot, k. Rages, and J. Veverka, the Crab Nebula from a Ba1]oon-Bome of Gig " (-7.5 ± 2.7) X10""/yr. "The Angular Separation of the Spec- Telescope", Bull. Am. Astrun. Soc. Other astrophysical and geological troscopic Binary B Scorpii A", Bu,1.j, 6, 437. The observation was made in data, most of which tends to favor a Am. ,astron. Soc. 6, 460. The sharp a range Of 20 - 150 KeV over Sas- decreasing gravi tationa1 constant, spikes in the 1ight curves of the katchewan On 1974 August 13. The e- were entmerated. See p. 9 - IQ of 797T May 13 occuitdtion by Jupiter mitting region was elliptical, with the first issue. are shown to be well-focussed one- a 20" long axis perpendicular to the dimensional images of this spectro- long axis of the optical crab. N. M. White, "Angular Diameter of µ scopic binary. Using both imersion NP0532 was about 9" from the center Gemi norwr', Astron. ,;. 79, 1076. and emersion data, the p.a. and sep- of the emitting region. The observa- Four photoelectric obseFations made aration (O:OOO7) were determi ned, as tion was planned so that both inner- with V or y fi1ters with 24·, 31, and well as the angular diameters of the sioh and emersion took place at flat 42-inch telescopes at Lowell Obser- stars (O:'OO0198 and cr;ooo117). Using areas of the moon. vatory during occultations on 1973 the estimated distance to $ Scorpii Oct. 17 and 1974 Feb. 4 result in an and the spectroscopic orbital data, S. T. Ridgway, D. C. Wells, and D. F. angular diameter of 0!'0121 ± O:'OO01 the stellar radii are found to be Carbon, "Diameter of 11 Geminorum M3 for a uniform disk. If a disk dark- 8-0 ± 3 and 5.0 ± 2 times that of III from Lunar Oecultation", Astron. ened to the limb were assumed, the the sun, and the mass ranges are J. 79, 1079. From photoelectric ob- diaeter would be slightly larger. 24 - 40 and 13 - 23 solar masses. SCrWtions made in three colors with Infrared magnitudes were used for an the ]5(}-cm McMath solar telescope at inproved b01oetric correction which g. uta11Cn, "XP-65 Occultation Predic- Kitt Peak on 1974 Feb. 4, a diameter was used to calculate an effective tion Program", unpublished, Mexico of 0!'0137 ± 0!'0010 was determined temperature of 3880" ± 'tO" K at the City (address in 1974 July roster). for a disk darkened by gCl% at the surface of the star.

FLORIDA GRAZE OBSERVERS MEET observers as well as some so new that Favorable and marginal conditions were they are not included in the latest also simulated. PUshbutton and voice Thomas H. Campbell, Jr. roster of ubservers, new conputors, signal reactions were measured. Re- expedition leaders and profile plot- sults of tests are row beigg analyzed, As Joan and David Dunham planned to ters. It was a very useful meeting. and I am preparing a paper, which will be in Tanpa for the Sixth Annual Meet- with Dr. Dunham giving us much insight be available to anyone who sends me a ing of the Division of Dynamical As- as to haw our data are handled and re- self-addressed envelope bearing the trononqy, at U.S.F. , he and I arranged duced. There was a long question and appropriate postage for 2 ounces. Pre- a special meeting at my hoe in Temple answer period. liminary results show personal equa- Terrace, for the evening of Decenber tion averages to be OS3 by pushbutton 8th. Several gra2e observers, from An electronic digital reaction time and OS4 by voice, un&r highly favor- different cities in the central Flori- tester was constructed in time fOr the able conditions, and about 054 and da area, attended; Wayne Green, Joe meeting, and was successfully used. A 055, respectively, under marginal con- Ruertas, Harold Povermi re, Bryan Sic- light emitting diode was used as an ditions. buhr, Rita Fairman, Dan Bricker and artificial star. It was possible to 5405 98th Avenue Lee Ford. The group included long-time simulate D's, R's, blinks and flashes. Tenple Terrace, FL 336]7 26

SFPARATIAN n F T H E TERMINATOR FROM T H F 3ARK LIMR

Tahle prepared usimz n. Id. Dunham's O.R.0,-VITT fnrmulac'. For each value of E1onciation (unper nart of table) or Percent qllnl it (lower part), there are ? rows of fiaures, omitting all hut the first value above 10 seconds for each Cusp Ande, ,ind"aT1 negative values. lfnpc'r row is separatinn, in seconds of arc, nf the mean 1imh theoretical terminator from the dar"k mean I imb. Lower rnw is fnr the "worst" tpmrfnator (2-mile-hicih mountains) . Al low for irradiation! H. F. DaBo11

F1ong. C tl S P A N G L E or % Snit 1" 2° 3° 4° 5° 6° 7° 8° q° 10° 12° 14° 16° 18° 20° 25° 30° 40° 50° 60° 70° 80° 90°

179 .000 .000 .000 .001 .001 .902 ..Sc)2 .C()3 .003 .004 .006 J)08 .011 .014 .m 7 .025 .036 .059 .083 .107 .126 .138 .142

178 ,000 .001 .002 .003 .004 .006 .008 ,011 .014 .01 7 .025 .033 .043 .054 .066 .101 .142 .235 .333 .426 .502 .702 .568 . _ . 177 .000 .002 .003 .006 .01 0 .014 .019 .025 .031 .039 .055 .075 .Oq7 .122 .150 .229 .320 .529 .751 .960 1.'3 1.24 1.28 - ~ . - . 176 .001 .003 .006 .OIl .017 .02S .034 .044 .056 .069 .098 .133 .173 .278 .267 .407 .570 .942 1.34 1 .71 2.01 2.21 2.28 m - .003 .007 175 .001 .004 .010 .01 7 .027 .039 .053 .069 .087 .108 .154 .209 .271 .341 .417 .637 .892 |.47 2.09 2.68 3.15 3.46 3.57 .119 .185 .210 - - .000 .042 774 .002 .006 .014 .025 .03q .056 .076 .100 .126 .155 .222 .301 .391 .4Q1 .602 .919 1.29 2.13 3.02 3.86 4.55 4.99 5.15 m . .001 .093 .283 .489 .643 .699 173 .002 .009 .01 9 .034 .053 .077 .104 .136 ,172 .212 .3()4 .41 1 .534 .671 .822 1.25 1.76 2.90 4.12 5.27 6.20 6.81 7.03 ~ e + .072 .354 .740 ).11 1.38 1.48 172 .003 .mi .025 .045 .070 .101 .137 .178 .225 .278 .3Q8 .539 .699 .87q 1.08 1.64 2.30 3.80 5.40 6.90 8.13 8.93 9.20 + - .006 .2($1 .784 1.41 1.99 2.40 2.54 171 .004 .014 .032 .057 .089 .128 .174 .226 .286 .352 .505 .684 .888 1.12 1.37 2.09 2.92 4.83 6.86 8.77 10.3 11.3 11.7 ~ m .000 .071 .570 1.38 2.31 3.13 3.70 3.91 170 .004 .018 .040 .071 .110 .158 .215 .281 .355 .437 .626 .848 7.10 1.38 7 .6q 2.59 3.62 5.99 8.50 10.9 + ~ . .026 .208 1.00 2.16 3.42 4.54 5.30 5.57 168 .006 .026 .058 .102 .160 .230 .313 .408 .515 .635 .910 1.23 1.60 2.01 2.46 3.76 5.26 8.70 12.4 m ~ .013 .233 .7(R 2.23 4.24 6.34 8.15 9.38 9.81 166 .009 .035 .079 .141 .220 .317 .430 .561 .7Oq .874 1.25 7.717 2.20 2.77 3.39 5.17 7.24 12.0 m 7.0510.2 12.9 14.7 15.3 + .000 .038 .139 .650 7.50 3.97 164 .OR .047 .105 .186 .29) .419 .569 .742 .Q38 1.01 1.66 2.24 2.91 3.66 4.48 6.84 9.58 m + ~ + + .000 .050 .186 .403 1.29 2.60 6.23 10.6 162 .015 .060 .i35 .239 .374 .538 .731 .953 1.20 1.48 2.13 2.88 3.74 4.68 5.75 8.79 12.3 - e + + .040 .18Q .448 .812 2.15 4.04 9.06 160 .019 .075 .169 .300 .469 .674 .917 1.20 ].51 1.86 2.67 3.61 4.69 5.90 7.22 11.0 ELG % Snit ~ + - .014 .148 .422 .831 1.37 3.26 5.82 12.5 96 .026 .103 .232 .412 .642 .924 1.26 1.64 2.07 2.55 3.66 4.qS 6.43 8,n8 9,89 180 100.00 2.55 . . . .OM .132 .457 .972 1.67 5.47 9.30 )79 99.99 95 .033 .133 .299 .532 .831) }.19 7.62 2.11 2.68 3.30 4.73 6.40 8.31 10.4 12.8 178 99.97 m ~ . ~ ~ .003 .054 .34Q .8Q6 1.69 2. 72 3,97 8.04 13.3 177 99.93 94 .041 .165 .372 .661 1.03 ].48 2.02 2.63 3.32 4.09 5.87 7.95 10.3 176 99.88 — ~ ~ . . .000 .047 .]63 .646 1.44 2.54 3.93 5.60 10.9 175 99.81 93 .050 .200 .449 .798 1.25 1.79 2.44 3.18 4.02 4.95 7.09 9.60 174 99.73 — m . . . .016 .120 .322 1.01 2.08 3.51 5.30 7.42 173 99.63 92 · .059 .237 .533 .946 1.48 2.12 2.89 3.77 4.76 5.86 8.40 11.4 172 99.51

+ + 1.45 . .000 .060 .235 .526 2.81 4.61 6.83 9.44 171 99.38 91 .069 .277 .622 1.10 1.73 2.48 3. 37 4.41) 5.56 6.85 9.81 170 99.24

m ~ 1.% ~ . . .010 .129 .384 .773 3.64 5.84 8.52 11 .7 169 99.08 90 .080 .319 .718 1.28 1.99 2.86 3.89 5.08 6.41 7.'in 11.3 168 98.91 . . . . .037 .223 .565 1.06 2.51 4.56 7.1? 10.4 767 98.72 89 .091 .365 .822 1.46 2.28 3.28 4.45 5.81 7.34 9.04 166 98.52

+ 3.i5 5.58 8.69 . . . . .081 .341 ,77a 1.39 165 98.30 88 .104 .415 .934 1.66 2.59 3.72 5.06 6.60 8.34 1f).3 164 98.06 - - .003 .141 .482 1.03 1 .77 3.86 6.71 10.3 163 97.82 87 .117 .469 1.05 1.87 2.92 4.21 5.72 7.46 9.42 162 97.55 . . . W .016 .217 .649 ].31 2.20 4.64 7.96 161 97.28 86 .132 .527 1.19 2.11 3.29 4.73 6.43 8.39 10.6 160 96.98 . . - .038 .310 .841 1.63 2.67 5.51 9.33 85 .148 .591 1.33 2.36 3.69 5.31 7.21 9.41 156.93 96 m . . .072 .422 1.06 1.99 3.21 6.48 jn.g 154.16 95 84 .165 .660 1.48 2.64 4.12 5.92 8.OS 10.5 151.64 94 m m . .114 .550 1.31 2.3Q 3.79 7.53 149.32 93 83 .184 .735 1.65 2.94 4.59 6.60 8.97 147.14 92 . . .168 .699 1.59 2.84 4.44 8.7() 145.08 91 82 .205 .818 1 .84 3.27 5.10 7.34 Q.98 143.13 90 ~ W .om .233 .869 1.91 3.34 5.17 10.0 141.26 89 81 .227 .909 ?.04 3.63 '5.67 8.15 11.1 139.46 88 . . .007 .311 1.06 2.26 3.9n 5.98 137.73 87 80 .252 1.01 2.27 4.03 6.29 9.05 136.05 86 + + .0?8 .402 1.28 2.66 4.53 6.88 134.43 85 79 .280 1.12 2.52 4.47 6.98 10.0 132.84 84 + .OS . . . .508 1.53 3.11 5.23 7.8q 131.30 83 78 .311 1.24 2. 79 4.96 7.75 129.79 82 m m . .057 .631 1 .82 3. 61 6.01 9. 01 128.32 81 77 .345 1.38 3.10 5.51 8.60 126.87 80 . .087 .772 2.14 4.18 6.8q 1').3 125.45 79 76 ,383 1.53 3.44 6.12 9.55 124.06 78 .935 2.50 4.82 7.88 . . .123 122.68 77 75 .426 1.70 3.83 6.80 10.6 121.33 76 m . .168 1 .12 2.92 5.54 9.M 120.00 75