Ocmthlion3Newstelter
Volume II, Number 4 August, 1979
Occultation Newsletter is published by the international Occultation Timing Association. Editor and Compositor: H. F. DaBo11; 6 N 106 White Oak Lane; St. Charles, IL 60174; U.S.A. Please send editorial matters to the above, but send address changes, requests, matters of circulation, and other IOTA business to IOTA; P.0. Box 596; Tinley Park, IL 60477; U.S.A.
IOTA NEWS seem bound to be broken. There are several grazes by the 59% sunlit waning moon as it makes its favorable David hi. Dunham passage across the Hyades cluster, culminating in one of the best Aldebaran grazes of the series. Some Hans-joachim Bode reports that postal rate increases information about known expeditions for grazes of in the German Federal Republic make it necessary to the brighter stars is listed below. [Dated 8 Aug 79] raise annual IOTA/European Section dues to DM 12.--. Unfortunately, this change was not made in the no- Approximate Location Organizer Telephone tice to observers which is being distributed with USNO'S regular XZ predictions for 1980. Aldebaran (mag. 1.1) Arvin, CA David Hale 805,871-7116 Using Kukarkin's most recent catalogs, David Herald James Van Nuland 408,371-1307 has prepared a comprehensive list of variable star China Lake, CA James McMahon 7]4,446-3237 data in the zodiacal region. After it is crossrefer- southern Nevada Ed Grayzeck 702,739-3563 enced with the XZ catalog, it will be published by Colorado Paul Asmus 303,978-032] IOTA. It also will be put into machine-readable form Stockton, MN james H. Fox 612,436-5843 so that at some later date, fairly complete variable Black River Falls, WI John D. Phelps 312,532-2968 star data might be printed directly on predictions Vanderbilt, MI Homer F. DaBo11 312,584-1162 of total and grazing occultations. north of Ottawa Brian Burke north of Montreal David Brown 514,481-4153 FROM THE PUBLISHER Drumondvi11e, Quebec Andre Cou1ombe 819,472-2828 For subscription purposes, this is the second issue Thetal Tauri (mag. 3.6) of 1979. southeast Manitoba Richard Bochonko 204,474-9501
Coupons for reporting counts of occultation timings ' Theta2 Tauri (mag. 4.0) in 1978 probably will be included in the next issue. British Columbia Rich. Linkletter 206,479-1191 near Edmnton, Alta. john Howell 403,252-6360 o.n.'s price is $1/issue, or $4/year (4 issues) in- cluding first class surface mailing, and air mail to Z.C. 677 (mag. 4.8) Mexico. Air mail is extra outside the U.S.A., Cana- near Phoenix, AZ Frank Reed 602,945-4880 da, and Mexico: $1.20/year in the Americas as far near Albuquerque, NM james Theiler south as Colombia; $1.68/year elsewhere. Back is- n. of St. joseph, MO Robert Sandy 816,763-4606 sues also are priced at $1/issue. Please see the Milwaukee, HI Raymond Zit 414,342-4037 masthead for the correct ordering address. Roscomon, MI Homer F. DaBo11 312,584-1162
IOTA membership, subscription included, is $7/year Z.C. 659 (mag. 6.4, SAD 93925) for residents of North America (including Mexico) Frederick, MD Wayne Warren 30],474-0814 and $9/year for others, to cover costs of overseas northern New jersey Roger Tuthi11 201,232-1786 air mail. European (excluding Spain and Portugal) Stamford, CT Charles Scovi1 and U. K. observers should join IOTA/ES, sending northwest Rhode Island Wm. Penha11ow 401,322-7186 DM 12.-- to Hans J. Bode, Barto1d-knaust Str. 6, Boston, MA area Dennis DiCicco 617,926-2678 3000 Hannover 91, German Federal Republic. Spanish, Philadelphia, PA area Emil Volcheck 215,388-1581 Portuguese, and Latin American occultation observers New Haven, CT area Edward Wetherbee 203.389-1198 may have free membership in IOTA/LAS, including Oc- northeast Texas Don Stockbauer 713,488-6197 cultation Newsletter en Espaiiol; contact Sr. Fran- cisco Diego Q;. Ixpantenco 26-bis, Real dc Ids Z.C. 672 (mag. 6.6, SAD 93961) Reyes, Coyoacan, Mexico, D.F., Mexico. south of Dallas, TX Paul Newman 214,494-3973 northeast Texas Don Stockbauer 713,488-6197 HYADES GRAZE EXPEDITIONS Pittsburgh, PA area Robert Clyde 216,274-8882
David W. Dunham 115 Tauri (mag. 5.3, close double, Sept. 13 a.m.) betw. Dallas & Houston Don Stockbauer 7]3,488-6197 If clear skies prevail over most of North America Mississippi Ben Hudgens 601,924-4705 during the morning of September 12th, some records s. of Washington, DC Wayne Warren 301,474-0814 32
MORE OCCULTATIONS OF STARS BY CERES AND VESTA to monitor the event in any case; possible satel- lites could occult the star at any location shown on David hi. Dunham the regional map.
Some occultations of faint stars, not included in My calculations of the 1980 Jan. 3rd occultation the list of 1979 planetary occultations on p. 17 of utilized the measured Lowell position of the star. the February issue, are given in If the star's SAD data are used, the list below. The format of the m, a) o?"" P- - list is similar to that of the " —1 g: ccjcjld ""· """"°~
Address inquiries to: Astronomical Division, Hydrographic Department, Tsukiji-5, Chuo-ku, Tokyo, 104 japan.
Occultation of BD -4° 217 by (I) Ceres, 1979 july 31 Diameter ]020 km = 0:57 Cp 0 ~ L,\j" 7":; J : " ,tf1,>,
<% O " %:zn L k a _ o" ¥ \ hr w| "e : " e & V\"g,, jh 30" t 0.° \ lb\u" : ~ \
E 0 ,,, , * I"
" \ " m © 9
b -O jh 32" jb z'r
'h:S t .5) sI ,s 1 6 16 46
LON611UOE Occultation of Lowell #15 by (I) Ceres, 1979 November 27 Diameter ]020 km " 0:62 GK " C' &f °.2 I S N ' ' ) ' '"
*
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Loorrm 34
DETERMINATION OF THE SUN'S RADIUS FROM the same star at both limits during a lunar eclipse. TOTAL SOLAR AND TOTAL LUNAR ECLIPSES The lunar polar radii needed for absolute calibra- tion of solar eclipse edge observations could be de- David Id. Dunham termined to an accuracy of perhaps 0'.'02 from such simultaneous graze data. During the September lunar A preliminary report of the successful observations eclipse, the moon will pass south of the center cjf of last February's solar eclipse from several loca- the umbral shadow, so that northern-limit grazes of tions near the edges of the path of totality was faint stars during totality will be relatively easy given in the last issue, p. 21. A study of the 2nd to observe. Four or five northern-limit grazes of and 3rd contact timings indicates a north shift from SAD stars might be seen from the U.S.A. But at cen- our predictions of 0!'3 and a correction to the solar tral eclipse, the southern limb of the moon will radius with respect to the lunar radius, of +0!'14. have an umbra1 distance of 92%, so that a star at The latter result is in almost exact agreement with least as bright as 8th magnitude probably will be David Herald's value determined from Australian ob- needed for reliable southern-limb observations. I servations near both edges of the path of totality computed the southern limits for the north-limb of the 1976 October 23rd solar eclipse. Workers at grazes which occur in the U.S.A. to see if there USNO and I plan to examine less extensive data ob- were any possibilities during the September eclipse. tained near both edges of the total solar eclipses The best prospect was 6th-magnitude 78 Aquarii = of 1970, 1972, and 1973. We also are working with Z.C. 3360 · SAD 146382, but its southern limit cros- Paul Muller in England to analyze data from the so- ses the Pacific Ocean, entering northern Peru at a lar eclipse of 1715 May 3rd which, thanks to the ef- time when the south limb will be a short distance forts of Sir Edmund Halley, was successfully ob- outside the umbra1 shadow, making reliable observa- served from near both edges of the path of totality tions impossible. After September, there won't be in England. From a comprehensive analysis of these another total lunar eclipse until 1982. observations, we should be able to examine possible small variations in the solar radius during much of The following expeditions probably will be undertak- a sunspot cycle and over a time span of 264 years. en for grazes during the eclipse in the U.S.A.: A Since the intensity drops rapidly by several orders Aquarii (mag. 3.8, in penumbra), near Norfolk, VA, of magnitude at the onset of' a total solar eclipse, led by David Dunham (phone 301,585-0989) and east these results are affected by irradiation and atmos- Texas, Don Stockbauer (713,488-6197); 78 Aquarii pheric seeing to a much smaller extent than direct (mag. 6.3), Boca Raton, FI, contact Tom Campbell transit circle observations of the sun. (813,985-1842); SAD 146387 (mag. 8.4), Fresno, CA, contact james Van Nuland (408,371-1307) or Garret During all total solar eclipses, the latitude 1ibra- ldimer (209,264-9771); and SAD 146395 (mag. 9.2), Po- tion is always near zero, while the longitude 1ibra- mona, CA, Robert Fischer (714,598-3476) and south of tion can have a wide range of values. Hence, virtu- Colorado Springs, CO, Paul Asmus (303,978-0321). ally the same lunar features determine the contacts for observers near the path edges for every eclipse, Observers interested in timing the 1980 February while this is not the case for observers near the 16th solar eclipse from near the path edges should center of the path. Consequently, detemination of coordinate plans with Hans-joachim Bode, 3 Hannover, the solar radius from timings of the contacts near Bartold-knaust Str. 6, German Federal Republic. He the center of a solar eclipse path is more subject plans to observe near the southern edge, near Mom- to individual and 1ibration-dependent errors in basa, Kenya. I hope that some observers in India, Watts' lunar limb correction data than when edge ob- where weather prospects are quite favorable, also servations are used. will attempt timings near the edges of the path of totality. Analysis of solar eclipse observations can determine the sun's radius with respect to that of the moon to SATELLITES OF (9) METIS? an accuracy of about O:'OS. It would be useful to calibrate the results in an absolute sense for com- David Id. Dunham and Toshio Hi'"ose parison with other techniques, such as transit ob- servations. This would be possible from an accurate IOTA Special Bulletin #5 gave prcdicti,ni information determination of the lunar radius at 1ibrations sim- for two asteroidal occultations. E'esides the now fa- ilar to those during solar eclipses. The 1ibrations mous occultation by Herculina, data were given for are similar during total lunar eclipses, which also the occultation of SAD 165132 by|qetis on 1978 july provide virtually the only times when emersions can 12. Metis was near a stationary point, so that the be timed about as easily as imersions, and when occultation shadow swept more from north to south grazes can be observed at both the north and south than from east to west, just off the east coas': of limbs. Consequently, observers should make a special Asia. Penha11ow obtained a plate on July 6 when, due effort to obtain occultation timings, including re- to the slow motion, Metis was only about T from the appearances, during lunar eclipses. Lunar eclipse star. Dunham's predicted path using these data grazes are especially valuable for defining the lu- shifted west, so that Korea and/or western Japan, nar limb in the areas where solar eclipse contacts and the northern Philippines, would likely have an occur when observed near the edges of the path of occultation. Brian Marsden relayed the prediction totality, which give the best results for the solar to Dr. Sinzi, who notified Hirose and others. IOTA radius, as noted above. Information about this Sep- sent a telegram to the Philippine Atmospheric, Geo- tember's lunar eclipse is given on p. 37. The moon's physical and Astronomical Services Administration position in the sky, and its librations, during the (PAGASA) urging observation. Gordon Taylor also rack September lunar eclipse will be similar to those astrometric observations and computed a similar pre- during last February's total solar eclipse. diction. He notified potential observers in j"pati, PAGASA, and Boscha Observatory, Indonesia. Ernesto Of utmost value would be observations of grazes of Calpo of PAGASA made plans to observe from Manila 35
and from another site 140 km to the southwest, but shift from astrometric data of which I am aware), rain foiled this effort. just off the earth's surface above Antarctica.
Hirose coordinated attempts by Japanese amateurs, AUREOLE AROUND (224) OCEANA canceling an expedition to Hokkaido (favored by the nominal prediction) and encouraging observers in Eduardo V. Przyby1 and David w. Dunham western Jakan upon learning about the newly predict- ed path 14 before the event. Unfortunately, rain In his Spanish-language book, Astronomia, Editia1 and clouds prevented observation from Tokyo and far- RamOn Sopena, Barcelona, Spain, 1957, jqsC Comas ther west, but six observers north of Tokyo did have Sola states on p. 340 (translated into English): "in clear skies at the critical time. Yoshihiro Musashi, some cases, for example Occam, the minor planet ap- Kawasaki City, found Metis' visual magnitude to be pears to be enveloped in an aureole when photograph- about 0.6 mag. brighter than the predicted V mag., ed." Could this effect be related to the "turbid im- so the drop in case of an occultation would be only age" or "somewhat diffuse" observations of stars a little more than 1 mag. Haruhiko Ono saw such a around the times of recently observed asteroidal oc- drop, of only 052 duration. Other possible dimnings cultations, caused by a cloud of small orbiting sat- were seen by two others, but they were uncertain; ellites? (224) Oceana is an M-type asteroid expected atmospheric scintillation was reported. Apparently, to have a diameter of 59 km. Unfortunately, orbital an occultation by Metis itself was not observed. elements accurate enough for comparison with star catalogs to predict possible occultations are not UNSUCCESSFUL ATTEMPTS FOR OTHER currently available for this minor planet. Elizabeth 1978 JULY-AUGUST OCCULTATIONS Roemer reports that observers sometimes claim to see aureoles when guiding for photographs of asteroids. David Id. Dunham LUNAR OCCULTATIONS OF PLANETS On july 29, Penha11ow made astrometric observations to try to improve the prediction for the occultation The maps showing the regions of visibility of lunar of SAD 93064 by (65) Cybele on August 1. My analysis occultations of planets are reprinted by permission of his results indicated that the path would be 0!'8 from the Japanese Ephemeris for 1979, published by south of the nominal prediction, so that the event the Hydrographic Department of japan. Region 1, only might be observed from the north central United R visible; Region 3, only D visible. States (see map on page 158 of o.n. I, #15). Observ- ers near St. Paul, MN; Denver, CO; Sioux City and -90' ' A0· 'L "-30" Marion, IA; and St. Charles and Lemont, IL, effec- I"J tively bracketing the predicted path, all reported R ' no occultation. Unfortunately, this spread of ob- servers was too small to catch the event; the occul- tation would have been missed if the shift from the "jS,, ' 0!'8 south line was as small as 0:'2 in either direc- tion. Lemont was at 0!'90 south; many attempts by ob- servers farther south and/or east were foiled by . d - clouds. In this case, the minor planet was 5 magni- 71'q)· tS' tudes fainter than the star, so that a magnitude "
there were a sizeable south shift. I have received · "3h ' " ii:'-8 \." no reports about this event, probably due to unfav- '— 1 IBO' orable weather. ,· : ·t--R_2_b—s.-g.A='g - : ' iaj ""' ' " Penha11ow's astrometry for the occultation of SAD , ]40167 by (45) Eugenia on July 19 indicated that the \ '.t rE paturn path would shift about 4" south (the largest path -- \ -30 . -60" -90' , -120' I -ISO' 36
PLANETARY OCCULTATIONS / /' * . '
-k : ~ '-" ,,Eg=?«e".":-7 I /1 R"// i, /" \ . - ~ -V" T "'7Nb ' " " · '. ' ". The world maps are produced by ' .h ' .i va C"C\ ·, :-., . Mitsuru SOma, the regional maps by ty4:": z:" """ ':8 ,, David Dunham. 'g' i'i='- " :)i", Q m )Q DO go H m PP PP ,/r',/' '"AA|,:\. III L h I |,1 ,,,"' 'i ':: ': AJ'j ")),"'jji'
Use a tracing of the cosine scale above to estimate star altitude ' ,h,'t ". ", Ld ""' '\ \ L! '' " h ' r ^,[j—t—/ -r--l jt' t from the world maps: place the 90° \ ' ' t' -4 /;/7" \ I' I ¶ — % N 0 ' \ . 4 mark at the center of the circular == "" ' L _4 A ' arc, and read the star altitude at the observing site. Lowell #8 by Ceres 1979 Aug 25 SAD 97988 by Antigone 1979 Sep 19 m
e' *' . "'" ""'z'j':- I . .A Baa'R.\ ) ,\ P ,y '":"Z:)ZG-'q¶'"-fu " ·'+:'\*., A ' 'r)'j'j)'"":|of· ,P:' - ')i)-; ·,." '"Zx i" .t7, r,:U-'"Fj' 'j]','!,
? !;-y-- i. "!""' ) 'ur%^- ' SIn V ""·'E'L:i""|'""",:KQT, '- )",gijtjl.p': \ \\ \T1, 7 ~ _m ~' : , ,,/ \ SAD 114497 by Juno 1979 Sep 27 SAD 98024 by Mars 1979 Oct 6 +19°1399 by Cybele 1979 Oct 17
Occultation of BD +19° 1399 by (65) Cybele, 1979 October ]7 Diameter 309 km = 0!'12 m ,0' Fir' i:· '
0m~
"~
"_ O: N " ""~.. "~ m _" , _Ao4 ±97 'C9 q » " _ O: N
~ L " """ — A dv M " T " : :ri — _ _2cj 38^ ~
U * "^ " 0.1 N" D % ~ E — 'i,
m. " "- , 0 \ 'qj — 0
" 0: 3 " 99 ' \ \ m I II I , J lCj aj 3J 40 m * LONGIW 37
EXTENDED-COVERAGE U.S.N.O. TOTAL OCCULTATION but I have not had time to do it yet this year. PREDICTIONS FOR 1979 Hopefully, it can be done for the 1980 predictions. The affected stars in the Hyades region have J-num- David hi. Dunham bers 4-389, 399, 404, 419, 426, 430, 441, and 454. '
Magnetic tapes have been prepared only recently to A new catalog (M) was created for the 1979 September compute extended-coverage total occultation predic- 6th lunar eclipse star field from San Fernando A.C. tions for the remainder of 1979 similar to those data supplied by David Herald; see below. The A.C. distributed for ]978, described in o.n., i (13), data were merged with, and when appropriate, re- 138-140. The 1979 predictions are similar to those placed by nore accurate XZ data. In the DM field, for 1978, with some differences explained below. Z.C. numbers are given for Z.C. stars and X-numbers Computer time is currently very limited at USNO, so are given for non-ZC SAD stars. B.D. numbers are that fewer observers will receive extended-coverage given for non-SAO B.D. stars, whose magnitudes have predictions for 1979 than for 1978. Observers might been taken from the B.D. in many cases, the B.D. be able to increase their chances of receiving ex- visual magnitudes being preferred to the photograph- tended-coverage predictions for 1979 by requesting ic A.C. magnitudes. The DM zone identifies the A.C. them from me at P.0. Box 488, Silver Spring, MD zone with a letter B denoting southern declinations, 20907. Many will have to be content with the more as has been done for non-B.D. A.C. stars in the j- quickly produced but less accurate standard-coverage catalog. The first two digits of the DM number are version of the predictions using standard station the minutes of 1900 R.A. to be added to 22h for the data quite distant from the desired location. The center of the A.C. plate, while the last three dig- computer time situation is expected to worsen during its are the number oR the plate. Hence, M103 = B 8 the next several months, making it virtually certain 48172 is A.C. -8° 22 48m 172, and M378, whose DM is that extended-coverage predictions will not be com- given as B 7 60058, is A.C. -7° 23ho(y' 58. Only pre- puted for 1980 until sometime after USNO receives dictions for September 6th, to give coverage for the the new computer which they've ordered, delaying lunar eclipse, were computed and merged with the distribution perhaps until about the middle of 1980. 1979 J-catalog occultation tape.
The 1979 K-catalog predictions cover the interval OCCULTATIONS DURING THE LUNAR ECLIPSE OF 1979 SEPT 6 from late August until late November and include on- 1Y those stars which are not in the XZ catalog, David W. Dunham and David Herald about 1000 stars; details will be provided in an ar- ticle, "Errors in USNO'S XZ Catalog," in a forthcom- The charts and information presented here are simi- ing issue of o.n. Most of these are the Yale stars lar to those published in o.n. for previous lunar with no proper motions near jgh right ascension; oc- eclipses, such as the one last September (o.n., i cultations of them will not be visible during Decem- (16), 170). The two charts, one giving stellar iden- ber due to proximity of the sun. The K numbers for tifications and the other showing the tracks for 22 1979 are the same as those for 1978. cities in the area of visibility of the eclipse, were prepared by John phelps, jr., using computer No changes have been made to the J-catalog for the plots and data generated by Dunham at the U. S. Na- · 1979 predictions. However, in order to save computer val Observatory. The coordinates of the numerous time, all occultations with the moon more than 70% non-SAO stars were calculated by Herald using data sunlit were omitted from the final tape used for the from the San Fernando zones of the Astrographic Cat- predictions. This is because few occul.tations of alog (A.C.). non-XZ and non-k stars are observable at highly gib- bous lunar phases. An error on a magnetic tape made Tick marks along the paths of the moon's center it necessary to prepare the final 1979 J-catalog oc- shown for various locations on the-second chart mark cultation tape from two tapes. The concatenation was integral hours of U.T. from gh to 13h; the motion is not entirely.successfuL resulting in duplicates for from right to left (the moon's right ascension is most of the occultations during October 26th. The always increasing). If less than"five ticks are error was corrected, but only after. predictions for shown, the path begins or ends at 4° moon altitude, several stations in North America and the western the low end being identifiable by the abSence of a Pacific Ocean area had already been computed. Anoth- tick at that end. Times of umbra1 eclipse events are er error was uncovered by Keith Horne when he ob- as follows: First contact, 9h17|!|9 U.T.; start of to- served the 1978 September 22nd Hyades passage from tality, 10h31'!'3; mid-eclipse, 10h54n2; end of total- Mt. Wilson Observatory, California. He noticed that ity, 11h]7'!11; and last umbral contact, 12h3®5. The the predictions for many of the.fainter stars were cities corresponding to the numbers'given at the off by several seconds. The reason for the error is ends of the plotted tracks are listed in Table 1. that the positions for the non-SAO and non-AGK3 The lunar radius varies from 16:75 when the moon is stars were taken from the A.C. with epoch near the on the horizon to 1tOS when it is in the zenith. turn of the century, and an average Hyades proper The position angle of the lunar equator will be motion was applied to all of these stars. The cur- 246°, to help in locating reappearing stars using rent positions of these fainter stars which are not lunar features if Watts angles are not included in Hyades members, for which it would have been better your predictions. The star field can also be used to to use no proper motions, are consequently about 8" locate emerging stars. The Leningrad Ephemerides of from the positions which I have used, on the aver- Minor Planets shows that there will be no occulta- age, in P.A. 285°. This means that the actual occul- tions of asteroids during this eclipse. tations of these stars will occur about 20S earlier than the times given in my predictions. Only a few On the map identifying the stars, the Zodiacal Cata- of these fainter stars actually are Hyades members. log number is given for Z.C. stars. Add 146000 to I hope to identify them from published Hyades mem- the three-digit numbers given for non-Z.C. stars to bership lists and correct the J-catalog accordingly, obtain the star's SAD number. The USNO rctference 38
number (in the special M-catalog created for this stars noted as B.D. or A.C. stars. The M-numbers are eclipse from Herald's list) is given for non-SAO given in the extended-coverage USNO total occulta- CO W
O So e '. k 9 Z .2 LG) :' , I t , &; E: ia 'S, +2 S 3? 3 L? S O = + 'A S m D U) r + ' LO , " U, ,4" * ¶ 8 S "U) " N r U)° " ""> 6 X U "S \J % 0 r& IS) 0 k °· "- "i ii,9 N, ' k P° n' N ¥U- R° KKD ' A, ' L SU C'J e! ! " ~" ?8 %k n ;,:!S; 'I? 'H;^ ", , : "' LC)
E ! "' $ , 7 y',S, '" ' :;:k ? ad e }!Nk ;i
" 'I!m TI!! 20 tO ??° F?D M0 Q, W aV tF S' ?' N",N ?*U,:zjt? :q m'! "':??s"uP" uj " d- LA " ' ° m k : , ? gZ " Eb? '2" S 7 · " t : ? d s!,N:i'!E ' u; ;s,e,s ,§ !" ;qs " , K ! I ii , :" ! ;j !; t::!:l!i}j'°f'!§o| d!il,! ,t|!:iij{?,|§!ji t! , 8 s,q" , ? "? zi"f j" ? ,7 ES 8 °";q !Eg,m2.F!":3E'F?: ? !
t m R ¢*j - · * ·S,", "¶ d " \' ' ib { - CD y" ! , j;'.' "ii'!z?S!! k,ZS! %9! f£° ;a:, ! ' ;q LA
,')"")1/jijj':!;)))'::'.)'J):j!)))i|t' i))" G) 'YJ C\J i ' ?"E |ti@;'j :!s-!'|::;g"! '"i!! t ! :!i C'J
0 P · 0 = LG)
a 0 a0 aN e. ,!2 ~0 ? < 3m 3m m. _ ,3 ?: ? ~ ~ ~G m ¢U bj Z: Zz: i3 * W a CD (D m (JO CD t I I 39 tion predictions for the eclipse, which might be ob- from Dunham at P.0. Box 488, Silver Spring, MD 20907 tained (depending on time and computer availability) (phone 301,585-0989). Observations of occultations *
* // K} I?'"m / g© K N // )K / k CJ LG) , N '7 W H 4- + I ,/ //
, ,W , e , / , " //' NG ° W 0 / , Q " d "+ - r " " ° : O ° ° L ° ,j: · f ," /j°, , C'J D LI) + qW Q" , ° + B / "" , , : ' ,^ r ") · ° " %/ 0' gl
D O N m ?- -+ " d p Q N + m 4 O ° d YIf 0, . % ' , ,," / M'0 d- O "F 6 e 0 B. 'F + D D 0 e- 0 q 6 (Si m 0 0 + 0 b N D + D t D ' ' -( + a iP "+ + 0 % B Q D Ch / 0 u B * O + H 6 · + " " (I rD m , ± :°m , ,1 ", 7 N C , 0 Lin ' 0 0 e °0I +Q e + m 0 0
B O , B 0 O ej ' -+ + q Q uj O + + D m 0 4 0 un D . / ,0 + Q. + L..
0 O Ln O-fV) :+ * + D t : D m / BE' " ® 2.Q :t I + = t n DO qcj C " CO W + 0 'C> · T7 0 0 P m LG) aj H O m / = + I b ' - a} + $1 B + S H 0 ¥ + ,+ % ' Ub = cn H O 0 EE a 2 D 0 D CL S + =- D)- Wk
E , S?, a d + · , —O ~O 4^
0 + u ' ° H 0 D " 0 0 ""4-pFO O-p"KJ S.L " : " · " ° ,, ,¶/. W ," ° " : : S a U O ¥ + t / B + CJ + "4+,r Ck 4- , at2a 2 st7 q ' , m '"1 D + 0 + Cn C7¶ ~ CC) , 0 e , + m · ""2 2 2b a D 0 q q 0 0 cn Gn DD 0 S C %C ·L = C'J 0 e a Q e'j D Q Q 0 0 + L Q W + Q 0 ,P p QQ D QO " B qC N W ° W V D ¢J 'D — B + 0 0 D-J C\J NJ 0 Gb O D Q :3
W ° k , + L e · " ° " IK IK 2,,S "% 0 ' O Q D m LS7 uj :8 0 · © Q m LO W
m D S WW · P 0 0 LE)
+ aa aB O " § S 1- ·T 3 3 . 3 3 S 4U © q +J C.. 'J" S S 8 2 CO ZZ 2 a * N( e (D (D + CD DJ I I I 40 timed during the eclipse should be sent to Herald at ->·with an amplitude of 0.8 magnitude. It is not in the P.0. Box 254, 1doden, A.C.T. 2606, Australia; we will A.C. nor is it shown on our map. It is about 2s of prepare and publish a sunnary of all observations RA. west and 2:9 north of the llth-mag. star M00431 received in a future issue of o.n. or at the approximate 1950 coordinates, RA. 23h01m19s, Dec1. -6°26:6. Double stars in the field Z.C. 3353 = A Aquarii is a long-period variable, but are listed in Table 2; Z.C. 3389'S duplicity is in- with an amplitude of only 0.1 magnitude. The only ferred from spectroscopic data. other known variable star in the eclipse star field is EF Aquarii, a 10.6-magnitude eclipsing variable Table 2: Doubles in 1979 September 6 Eclipse Field
Table I: 1979 Sept. 6 Eclipse Tracks for 22 Cities Star(s) MAGI MAG2 SEP. PA. Code
1 Auckland 8 Manila IB Miami M00097 = BD -6°6098 8.9 9.3 1':2 136° M 2 Dunedin 9 Nanking 19 Kansas City SAD 146419 9.3 9.5 0.04 69 X 3 Brisbane 10 Perth 20 Mexico City ZC 3372 and M00222 8.7 10.1 20.2 201 D&E 4 Melbourne 11 Lembang, 21 Los Angeles SAD 146439 9.5 10.7 1.0 196 C 5 Tokyo java 22 Vancouver ZC 3388 6.2 6.3 0.18 192 0 6 Khabarovsk, 15 Anchorage 23 Bogota SAD 146499 9.0 13.1 3.3 77 C Siberia 16 Honolulu 24 Lima 3rd star 13.7 4.0 320 C 7 Taifiei 17 Montreal 25 Santiago ZC 3389 8.4 8.4 0.05? ? V
OCCULTATION TALLY AND PRELIMINARY ANALYSIS ers at the convention. Since most observers were lo- OF THE 1978 MARCH 24 LUNAR ECLIPSE cated at different sites, it is illustrative to plot the individual residuals against the Watts angles David Herald for each event, and compare this with the profile derived from Watts' charts. As can be seen from Fig. All reports of the eclipse so far received have come 2, there is a substantial difference in detail, from observers in Australia, and most of those were which, as any graze observer is aware, is not sur- ' from people attending the 8th National Australian prising. However, it does illustrate, yet again, the Convention of Amateur Astronomers, where the observ- limitations of Watts' charts, and the corresponding ers were extremely lucky; after a week of continuous uncertainties in residuals, after having been cor- cloud, seven hours of clear skies permitted most of rected on the basis of the charts. the eclipse to be observed. In all, 86 occultation timings have been reported so far, distributed as follows: ,,,. , " S " · Rank Observer Total # R's # SAD # 'K' # 'J' J " ~ Ii \ \" 1 D. Herald 17 5 5 6 6 I 2 M. Ashley 15 5 7 5 3 + 3 j. Stevenson 7 2 4 3 - / '\ 4 J. Elso 7 2 4 2 1 I \ , 5 N. Loveday 7 '- "3 2 2 6 G. Searle · 5 1 3 2 - , 270·{ 7 B. Jarvis 5 1 3 1 1 8 B. Soulsby 5 1 2 1 2 <6 i;",%. 9 F. Baker 5 - } 2 2 10 R. Price 3 1 3 - - ]1 R. Lanigan-O'keefe' 3 - I 2 12 B. Tregaskis 3 - 1 1 1 ' ""P " 13 I. Grant 1 - 1 - - * ,* " 7 14 G. Ke11ock ' 1 - 1 - - 4 / 15 L. Metcalf 1 - 1 -- * SAD \* ~ i 16 G. Spencer 1 - 1 - - + "K" ~ j ^ ^ "J" — " Totals 86 18 41 27 18 I a I' RADIAL SCALE I have reduced all the observations using the pub- N lished (1=2) lunar ephemeris assuming ET - UTC = Fig. 2 49518, and plotted the residuals on a polar diagram (Fig. I). On the plot, only the average residual for 0 KEAN LIMB u% FRN VAil" Char's _~~—-""""" all those observers attending the convention was plotted for each star, and SAD, AGK3 (K), and j cat- alogue stars are distinguished. As can be seen from LjNB FRQN RESIDKN-S the plot, there is good consistency between the re- .0!!5 _ siduals of stars in the different catalogues. The dashed curve corresponds to a least squares best fit to the residuals; it corresponds to a shift in the position of the moon of -0526 in R.A., and -0!'52 in declination. -i:o - b I I II 66?2 66?4 66?6 66?8 67?0 One star was observed to disappear by twelve observ- wins angle