Monthly Notes of the Astronomical Society of Southern Africa

Home , Crab Pulsar, Union Observatory

ISSN 0024-8266 mnassa Monthly Notes of the Astronomical Society of Southern Africa Vol 72 Nos 5 & 6 June 2013 mmonthly notes n of the astronomical as society s of southern a africa JUNE 2013 Vol 72 Nos 5 & 6

Roy Smith (1930 – 2013) 89 G Roberts......

Synchronizing High-speed Optical Measurements with amateur equipment A van Staden...... 91

GRB130427A detected by Supersid monitor B Fraser...... 101

Moonwatch in South Africa: 1957–1958 J Hers...... 103

IGY Reminiscenes WS Finsen...... 117

Astronomical Colloquia...... 122

Deep-sky Delights Celestial Home of Stars Magda Streicher...... 127

• AmateurA high-speed photometry • Moonwatch in SA: 1957–1958 • mateu • GRB130427Ar high detected by Supersid monitor • IGY Reminiscenes • GRB -spee 1304 d ph 27A otome detec try • ted b Moo y Sup nwatc ersid h in S moni A: 1 tor • 957–1 IGY R 958 emin • Downloadable online from h� p://www.mnassa.org.za iscen es • monthly notes of the astronomical society of southern africa astronomical society of southern africa editorial board Mr Case Rijsdijk (Editor, MNASSA) The Astronomical Society of Southern Africa (ASSA) was formed in 1922 by the amalgama� on of the Cape Astronomical Associa� on (founded 1912) and the Johannesburg Astronomical Associa� on Mr Auke Slotegraaf (Editor, Sky Guide Africa South) (founded 1918). It is a body consis� ng of both amateur and professional astronomers. Mr Chris� an He� lage (Webmaster) Publica� ons: The Society publishes its own electronic journal, the Monthly Notes of the Astronomical Prof MW Feast (Board Member, Univ. of Cape Town) Society of Southern Africa (MNASSA) bimonthly and an annual printed Sky Guide Africa South. Prof B Warner (Board Member, Univ. of Cape Town) Membership: Membership of the Society is open to all. Poten� al members should consult the Mr Case Rijsdijk (Editor, MNASSA) Society’s web page assa.saao.org.za for details. Joining is possible via one of the Local Centres or as mnassa a Country Member. Dr Ian Glass (Assistant Editor) production Local Centres: Local Centres of the Society exist at Bloemfontein, Cape Town, Durban, Harare, Her- Mr Maciej Soltynski (Book Review Editor) manus, Johannesburg, Pietermaritzburg (Natal Midlands Centre), Pretoria and Sedgefi eld district Mr Willie Koorts (Layout Editor). (Garden Route Centre). 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Treasurer Adv AJ Nel [email protected] rates per inser� on: full page R400; half page R200; quar- Hon. Secretary L Cross [email protected] ter page R100; classifi ed R2.00 per word. Enquiries and Scholarships MG Soltynski [email protected] copy should be sent to the editor at [email protected]. Members C Stewart [email protected] G Els [email protected] contributions MNASSA mainly serves the Southern African astronomical J Smit johanchsmit@gmail community, professional and amateur. Ar� cles and papers L Labuschagne [email protected] may be submi� ed by members of this community and by J Saunders [email protected] those with strong Southern African connec� ons, or else the L Govender [email protected] C Rijsdijk par� [email protected] papers should deal with ma� ers of direct interest to this Hon. Auditor RG Glass (Horwath Zeller Karro) [email protected] community. Due dates for contribu� ons are: Vol 72 Nos 7 & 8 (Aug 2013 issue), 01 Jul 2013 Directors of Sec� ons Vol 72 Nos 9 & 10 (Oct 2013 issue), 01 Sep 2013 Comet and Meteor Sec� on TP Cooper [email protected] Cosmology Sec� on JFW de Bruyn Tel. 033 396 3624 [email protected] recognition Ar� cles in MNASSA appear in the NASA/ADS data system. Dark-sky Sec� on J Smit Tel. 011 790 4443 [email protected] Deep-sky Sec� on A Slotegraaf Tel. 074 100 7237 [email protected] Double Star Sec� on D Blane Tel. 072 693 7704 [email protected] Educa� on and Public CL Rijsdijk Tel. 044 877 1180 par� [email protected] Communica� on Sec� on Cover: M1, the Crab Nebula Historical Sec� on C de Coning Tel/Fax 021 423 4538 [email protected] [email protected] This Hubble Space Telescope image of the Crab Nebula, M1 or NGC 1952, shows the Occulta� on Sec� on B Fraser Tel. 016 366 0955 Solar Sec� on vacant remnants of SN1054. It is currently about 10 light years across and has a rapidly rota� ng Variable Star Sec� on C Middleton, Tel. 082 920 3107 wbrooke@netac� ve.co.za neutron star, or pulsar, at its centre. See ar� cle on High Speed Photometry, p.91. astronomical society of southern africa capricornus: celestial home of stars ment is intended as a bungling spu� er to about 5’ diameter, showing several for a mere appendage to the speck of a more cluster members sca� ered across world on which we dwell, to so� en the the background haze of unresolved darkness of its pe� y midnight.” stars. Two short rows of magnitude 12 mnassa stars, leading away from the compact Monthly Notes of the Astronomical Society of Southern Africa Closer to home, a very realis� c observa- nucleus, catch the eye: one poin� ng Vol 72 Nos 5 & 6 June 2013 � on of Messier 30 by Auke Slotegraaf north, the other to the north-west. indicates the posi� on as lying in south- Roy Smith (1930 – 2013) eastern Capricorn, outside of the large M30 is almost 13 gigayears (Gyr) old delta-wing shape of the Sea Goat, in and has a mass of about 80 000 suns. by Greg Roberts the direc� on of the star Fomalhaut. He It lies 26 000 light years away from our further indicates M30’s integrated mag- Sun and moves in an orbit around our Roy Duchesne Fairbridge Smith was born nitude as V=6.9, and it is plainly visible galaxy, which is opposite in direc� on on 26 April 1930 in Kraaipan, Mafi keng through binoculars as a bright round to the rota� on of the galaxy itself. This where he grew up on a farm. He cometary glow, with a � ght nucleus, suggests that M30 was not formed as matriculated from Pretoria Boys High accompanied by the pale yellow mag- part of our Milky Way, but was, instead, School and started work as a scien� fi c nitude 5 star 41 Cap. Just 4’ west-south- accreted (gravita� onally captured) assistant at the CSIR’s Na� onal Physical west of the nucleus of the cluster lies when its own parent galaxy had a close Laboratory (NPRL) in 1948. Here he was a magnitude 8 star. A small telescope encounter with our galaxy. involved (amongst other things) in the shows it as a 3’-diameter glow, grow- development and maintenance of the ing slowly brighter towards the centre, Allow me the opportunity to thank Dale Na� onal Measuring Standards (NMS) of where it becomes suddenly much Liebenberg for the excellent pictures he so Mass, Pressure and Length. brighter, forming a defi nite, strongly gratefully contributes to the ar� cles that condensed, nucleus. The brightest stars are constantly share with the readers. During the 1950s Roy became a familiar In early 1957 the CSIR approached in M30 - its red giants - are between face at the Radcliff e Observatory through the ASSA amateurs for op� cal satellite magnitude 12 and 13, so a small tel- Don’t avoid the fi sh-goat. Grab it by the ASSA mee� ngs. He used to store his 10- tracking. Thackeray gave Roy permission escope will show a few individual stars. horns and use them to penetrate the inch telescope (mirror made and signed, to set up a tracking sta� on at Radcliff e. Larger telescopes bring the cluster up objects within its realm. “Calver ‘02”) in Mike Feast’s garden. The He took three weeks leave to assemble Director of Radcliff e Observatory, Dr about 15 telescopes based on the Object Type RA (J2000.0) Dec Mag. Size Andrew D Thackeray, asked if he would Union Observatory design and spent a assist at Radcliff e, earning some extra lot of energy establishing the Radcliff e RT Capricorni Carbon Star 20h17m2 -21°20 7 - 11 * pocket-money. On occasions Roy assisted Moonwatch sta� on. When Sputnik 1 NGC 6908 Nebulosity 20 25 1 -24 48 14 0.5’x0.3’ Dr Wesselink, usually up to midnight and was launched in Oct 1957, some visual NGC 6907 Galaxy 20 25 6 -24 49 11 3.2’x2.3’ some� mes all night over weekends! Since observa� ons were made by Roy and Asterism Star Group 20 26 7 -24 57 8 10’ he could start-up and operate the 74-inch the Radcliff e astronomer, Joe Churms, NGC 7099, M 30 Globular Cluster 21 40 4 -23 11 6.9 9’ Radcliff e telescope, he was asked to help who took some photographs. In 1969 Palomar 12 Globular Cluster 21 46 6 -21 15 11.7 2.9’ American astronomer, Dr Tom Gehrels, Roy used a 12-inch refl ector, set up at NGC 7158 Unknown 21 57 4 -11 36 9.5 ‘x6’ during his 3-week visit to the observatory the Moonwatch site at Radcliff e by the in July 1956. Pretoria branch of ASSA, to track Apollo 11 mnassa vol 72 nos 5 & 6 132 june 2013 mnassa vol 72 nos 5 & 6 89 june 2013 obituary deep-sky delights out to a distance of 160 000 km, on its way In June 1961 Roy resigned from the CSIR to the Moon. and returned to work at the Baker-Nunn camera un� l May 1964. In June 1964 Early in 1958 Pretoria Moonwatch was he returned to work at the NMS a� er supplied with fi ve Apogee telescopes receiving a request/invita� on from the of which four were set-up in Jack CSIR/NPRL to do so. From July 1961 un� l Benne� ’s backyard, from where Pretoria 1964, the CSIR sta� on had been run by Moonwatch operated. They did very well, LN Mar� ns who had worked with Roy totalling about 190 observing sessions in the NPRL. On Roy’s return to the CSIR during the IGY (Interna� onal Geophysical this sta� on got closed as Louw Mar� ns Year). The fi � h Apogee was mounted by had moved to the Cape. Un� l the offi cial Roy on the Baker-Nunn camera to replace closure of the Moonwatch programme the very small 2-inch aperture fi nder in 1975, Jack Benne� and Roy con� nued telescope, enabling the observers to see visual tracking alone at Moonwatch the satellites they were tracking with the sta� ons Riviera and Murrayfi eld. Although camera. Roy offi cially re� red in 1990, he con� nued working under contract in the Light The CSIR had promised the Smithsonian Standards Sec� on un� l early 1994. Astrophysical Observatory a South African observer for the Baker-Nunn camera Roy did some car rallying in his younger M 30 Globular Cluster, or NGC 7099, is a comet-like cluster, that moves the opposite direc- which they operated at Olifans� ontein days, the old Lourenco Marques Rally. He � on to the rota� on of the galaxy, probably as the result of an intergalac� c gravita� onal during the IGY. They seconded Roy there also enjoyed motorbikes but gave it all up encounter. Dale Liebenberg in March 1958 where he worked with a� er his children were born. Dr RC Cameron (sta� on manager) and slightly longer, giving the impression of ually more compressed in the middle. Claude Knuckles who were the American Roy was a long term member of the a pair of fi refl y antennae. The south- John Herschel, son of William, observ- staff during the IGY. Roy usually observed Astronomical Society of Southern Africa eastern part of the globular is broken ing with the 18-inch f/3 speculum at the the evening passes, whilst Claude, who from about 1954 to 2007 and was a Fellow down in starlight and in a way cut off by Cape of Good Hope, records the object lived closer to the camera, did the early of the Royal Astronomical Society, elected a short string of four stars. Also to be as “a globular cluster, bright, 4’ long by morning ones un� l December 1958. in May 1974, proposed by Thackeray. seen is a double star towards the south- 3’ broad; all resolved into stars, gradu- ern part. Messier 30 is a large globular ally more compressed in the middle. At the end of the IGY, the CSIR requested Roy was married to Margaret Anwyl Smith cluster that can be easily spo� ed with In this accumula� on of stars, plainly Roy to set up a permanent sta� on to for 55 years. She passed away fi ve years binoculars and measures nearly 90 light see the exer� on of a central clustering ensure that op� cal tracking would before him. He passed away on 19 June years in diameter. It is a very special power, which may reside in a central con� nue. In 1959 a Moonwatch sta� on 2013 and is survived by two daughters, object – one to remember long a� er mass.” was set up on top of a building in the CSIR Moira Sellers and Gillian Fouche and three observed it. grounds from where they operated un� l grandchildren, Jus� n Chris� e (26), Kayla Admiral William Henry Smyth, an English about 1964. Chris� e (25) and Kieran Fouche (13). In Philosophical Transac� on 1814, Wil- amateur, was moved to wild specula� on ... con� nue on p. 126 liam Herschel described it as a brilliant about the object. “What an immensity cluster, the stars of which become grad- of space is indicated. Such an arrange- mnassa vol 72 nos 5 & 6 90 131 june 2013 capricornus: celestial home of stars observers page with a small, barely visible arc-like patch Milky Way. Tom Polakis’ mo� on studies embedded in the north-east listed as suggest that Palomar 12 may have origi- Synchronizing High-speed Optical NGC 6908 (see picture). nated in the Sagi� arius Dwarf Galaxy, Measurements with amateur equipment but was probably later captured by the Andre van Staden ([email protected]) Just 15’ east of NGC 6907 is a lovely Milky Way. Asterism contains six colourful stars in The purpose of this inves� ga� on is to is basically research related, associated a prominent north-south arrow shape, Capricornus is home to the dis� nc� ve demonstrate a low-cost method for with high cost and applied mostly by the with the brightest star (HD 194412) globular cluster NGC 7099, or Messier measuring weak, rapid variable stel- professional domain. Another method at magnitude 8. It is quite prominent 30, also known as Benne� 128, which lar fl ux with standard amateur class is to use a stroboscopic system and a against a sparse star fi eld. is situated about 3 degrees east of the telescopes and CCD cameras. The standard CCD and was thought to have magnitude 3.7 zeta Capriconi. Messier nature of the fl ux under discussion is poten� al for the amateur astronomer. An object that is ques� onable is NGC 30 were discovered by Charles Messier op� cal, periodic and in the millisecond 7158, which forms a triangle towards (1730–1817) on 3 August 1764 near the � me frame. Combining measure- A stroboscopic system in terms of astro- the north-east from the stars magni- star 41 Capricorni. He devoted much of ments spaced over a period of days to nomical observa� ons will periodically tude 5 mu and magnitude 5.5 lambda his life to searching the skies for comets improve signal to noise (S/N) ra� o is capture a � med frac� on of the emission Capricorni. This is one of those objects and his notes indicate the object to be possible, but requires unprecedented by means of a synchronizing shu� er in which is nowhere to be found, but round, containing no stars and seen � ming accuracy, not common to op� - front of the CCD. The shu� er may be which, on closer inves� ga� on, appears with diffi culty in a good Gregorian 3 1⁄2- cal astronomy (Eastman, J. et al. 2010). any controllable light interrupter but is as a very faint string of three close stars foot telescope. A typical related applica� on is meas- usually a rota� ng wheel with cut-outs, between magnitude 9 and 11. Steve uring signals from a pulsar in op� cal synchronized to the frequency of the Coe, using a 13” f/5.6, notes: “Is given With low power it might well resemble wavelengths. A low cost system will source. By controlling the frequency as a triple star in NGC 2000 catalogue. a comet, in line with the comment of be introduced to demonstrate this and phase of the shu� er wheel, it is Sure enough, there is a triple with two the Reverend Thomas William Webb, a technology, capable of resolving the possible to resolve the phase or light members about 9th magnitude and one Bri� sh astronomer, born 14 December light curve of the 16.5 magnitude pul- curve by means of accurate CCD photo- 11th at this loca� on. They are separat- 1807 and died 19 May 1885, though sar in the Crab Nebula, with a 20cm metric measurements. ed by about 30 arc seconds in a straight some sources give his year of birth as telescope. line at 100X. This mul� ple star system 1806. He was the only son of a clergy- Stroboscopic systems were success- must have been included in the NGC man, and was raised and educated by Introduc� on fully applied to op� cal pulsar meas- because of its appearance at low power his father, his mother’s having died High speed photometers (Straubmeier, urements in the past. A more recent this group is nebulous. It is marked as a while he was s� ll a li� le child. However, C. et al., 2001; Nilsson, R. 2005) on paper by Cadez, A., et al, (2003) dem- galaxy on Uranometria 2000.” the globular cluster grows gradually large telescopes are the most common onstrated resolving of the Crab pulsar brighter towards a � ny, very dense and method for measuring high speed fl ux light curve with a 2.12m telescope to The rare globular cluster Palomar 12 bright core. Careful observa� on reveals variability. Various Instruments and a high degree with 9 degree cut-out (named a� er the Palomar Observatory), an image resembling an elongated modes for using CCDs were also suc- widths on a chopper blade. The re- situated rela� vely close to the Pisces north-south honeycomb covered with cessfully applied for high-speed astro- mainder of this paper will focus on Austrinus border, is around 60 000 light bees (see picture). With higher magni- physics in op� cal wavelengths. A list of a low cost, amateur version of the years distant. This globular cluster is fi ca� on faint stars mingle asterism-like such CCD techniques was compiled by stroboscopic system with the necessary related tasks, capable of resolving es� mated to be much younger than at random, with two prominent strings Dhillon V.S. (2007). Unfortunately, this the light curve of the Crab pulsar. The most of the globular clusters in our extending north and north-west, one type instrumenta� on and technology mnassa vol 72 nos 5 & 6 130 91 june 2013 high-speed optical measurements deep-sky delights author believes that accurate � ming is an essen� al ingredient associated with almost all high-speed photometry. This strobing system will provide an ideal opportunity to challenge and test the stringent � ming accuracy.

The Crab Pulsar in the geocentric centre of the Crab Nebula (M1) rotates at ap- proximately 30 revolu� ons per second and produces rapid fl uctua� ons in intensity as the E-M beam sweeps across Earth. At a mean op� cal magnitude of 16.5, it was es� mated to be a measur- able target with a 20cm telescope and a ST9e CCD camera. Timing ephemeris for the Crab pulsar is published monthly and available from Jodrell Bank monthly ephemeris (Lyne, A.G.). Fig.1 Crab Nebula also known as M1. This image was captured by Axel Mar� n from Concept Germany with a 30cm Newtonian Tel- NGC 6907 Its misty glow represents a miniature Large Magellanic Cloud. Dale Liebenberg In principle, the frequency of the shut- escope and ST8XME CCD + CLS-Filter. The ter has to be synchronized with the fre- unprocessed image is the sum total of 3.5 double star. In fact, four companions Another star, quite extraordinary in quency of the pulsar at the telescope. hours of exposure � me and shows the 16.5 are listed. Double star director Dave its own right, about halfway along Once the system is synchronized, it is Mag. pulsar (PSR 0534+2200) in the centre. Blane indicate that Alpha Capricorni the western boundary of the constel- possible to shi� the phase of the shut- is an op� cal double star with com- la� on, is RT Capricorni. It is a carbon ter rela� ve to the received signal and observe diff erent frac� ons of the emission ponents αlpha1 Cap and αlpha2 Cap star which glows with a lovely reddish period. The size of the frac� ons or samples is determined by the open-to-close having magnitudes 4.3 and 3.6 respec- colour that varies irregularly between ra� o of the shu� er wheel. If for instance an open-to-close ra� o of 1:2 is used, the � vely. They have a separa� on of 381” magnitude 7 and 11. measured fl ux will be an integral part of which the pulsar rotates an angle, 1/3 of its at a posi� on angle of 2920. αlpha1 is a rota� on period. The resolu� on of the pulsar light curve will be determined by the G type super-giant and αlpha2 is a giant Further towards the south-western open-to-close ra� o and the overall � ming precision of the shu� er phase over the star of the same spectral class. Each corner of the constella� on the galaxy accumula� on period of many cycles. component is in turn a mul� ple star, NGC 6907 displays a misty glow with with αlpha1 having a magnitude 9.6 an elongated shape in a north-east to In prac� ce, the instantaneous phase of the shu� er will always deviate from the companion with separa� on of 46.9” at south-west direc� on and strongly re- assumed phase due to systema� c errors. The shu� er phase at � me can be a posi� on angle of 2220, which is un- sembles a miniature Large Magellanic wri� en as: related, while αlpha2 has a magnitude Cloud. The centre area shows a small 10.5 companion with separa� on 153” star-like nucleus. Higher magnifi ca� on (1) at a PA of 1600. reveals kno� ed texture on the surface mnassa vol 72 nos 5 & 6 92 129 june 2013 capricornus: celestial home of stars observers page

Where isis thethe spin-downspin-down correctedcorrected phasephase ofof thethe pulsarpulsar atat � meme derivedderived from ephemeris, iiss thethe � mminging ccorrec�orrec� oonn aatt � mmee ttoo compensatecompensate fforor not observing from the Solar System Barycentre and other smaller � ming issues, aarere systema�systema� c errorserrors involveinvolve toto es�es� matemate aandnd aarere vari-various system errors, e.g. mechanical tolerances. Constant errors resul� ng in a bias of cancan bebe neglectedneglected forfor nownow butbut anyany varia�varia� onsons oror dri�dri� s fromfrom millisecondsmilliseconds toto daysdays must be dealt with and are discussed under Shu� er System and Timing Principals, see below.

The design criteria were to keep ( ) < 1/100 of the Crab pulsar rota� on period which relates to ~0.33 milliseconds � ming error of . If this crite- rion can be met, it will be a possible to have a high number of narrow sampling windows spread over one period to resolve the light curve in great detail. For fi rst trials a much lower sampling resolu� on was used with a shu� er open-to-close ra� o of only 1:2, but s� ll try to maintain the 0.33 milliseconds � ming precision.

In theory the design incorporates a closed-loop system that does not accumulate � ming errors (Fig. 2). The system starts with an es� mated shu� er frequency ( ) where isis thethe spin-downspin-down correctedcorrected periodperiod ofof thethe pulsarpulsar atat � me derivedderived fromfrom thethe ephemeris.ephemeris. TheThe shu�shu� erer op�op� calcal interrupterinterrupter producesproduces a

signal (Si) on each rota� on (i) of the disk that coincides with the mid-posi� on of one of the four windows. The exact universal � me, Ts(i) for the signal is derived from a GPS Clock (Van Staden, A., 2013) smoothed by a αβ - smoothing algorithm and the corresponding phase iiss calculated.calculated. ThisThis isis comparedcompared toto a pre-selectedpre-selected phasephase of interest, . The diff erence isis thethe correc�correc� onon phasephase neededneeded forfor toto maintain the shu� er synchroniza� on with the pulsar. To explore a new phase region simply means to dial-in a new reference phase, aandnd thethe closed-loopclosed-loop willwill auto-automa� c track on .

Shu� er System The Shu� er disk, 170mm diameter was made of a piece of Closed-Cell PVC foam board, also known as Forex (Wikipedia, 2013). A brushless DC (BLDC) motor from look-alike double stars and is, famously, The lovely double star, alpha Capri- the hard drive of an old PC a close neighbour to the centre of the corni, also the star closest to the Sagit- was stripped for the shu� er Milky Way. tarius boundary, is a wide, naked-eye Fig.2 Concept diagram. mnassa vol 72 nos 5 & 6 128 93 june 2013 high-speed optical measurements deep-sky delights

Celestial Home of Stars Magda Streicher [email protected] Fig.3 Shu� er Housing and Shu� er disk. Fig.4 Drawing of the Shu� er disk with the CCD Chip in the background. In an� quity the Capricornus constella- � on was seen as a monster with the head motor. BLDC motors is a type of synchronous electric motor, small, lightweight, have and forelegs of a goat and the posterior high speed ranges are acous� cally quiet and can be controlled almost like a stepper mo- of a fi sh. The creature could almost be tor (Yedamale P., 2003). Image source: Stellarium.org compared to the so-called Mermaid but could also some� mes, in the case of Cap- The blade has four cut-outs equally spaced and translates to ~7.5 revolu� ons per second ricornus, refer to the Fishman. (~450 rpm) rota� on speed when synchronized to the Crab pulsar frequency of 30 Hz (30 served towards the east it indicates the Hz/4 = 7.5 Hz). A pulse is produced once per revolu� on when sensor, A inin thethe shu�shu� erer The name ‘Tropic of Capricornus’ origi- point of the winter sols� ce, this sols� ce housing coincident with a small hole B in the rota� ng disc. nates from the fact that when fi rst ob- at present being 33o to the west in the fi gure of Sagi� arius. In theory the centre of the pulse should refl ect the instant when the geometric centre of the shu� er window overlays the CCD and the image of the pulsar coincides with a line The constella� on is special to the au- between AB and C (Fig. 4). Assuming the CCD centre coincides with the telescope op� - thor for two good reasons. Not only cal axis then amount of phase error rresul�esul� ngng fromfrom thethe offoff ssetet ooff tthehe ppulsarulsar ccanan bbee does she live right inside the old Tropic approximate by: of Capricorn Circle, but the image also refl ects a par� cular shape: it looks very (2) much like a huge lopsided triangle, and special in the star composi� on. Heaven where, iiss tthehe periodperiod ofof thethe pulsar,pulsar, F isis thethe effeff eec�c� vvee ffocalocal llengthength ooff tthehe ttelescope,elescope, iiss alone knows how anyone could see a 52mm and iiss angularangular offoff ssetet ooff tthehe ppulsarulsar ffromrom tthehe CCCDCD ccentreentre iinn tthehe ddirec�irec� oonn ooff sea goat with horns in that par� cular rota� on. Depending on the CCD orienta� on, mechanical tracking errors in the telescope star pa� ern, but be that as it may … We drive system will modulate � ming errors onto . The same guide star at the same will carefully unravel the constella� on, CCD posi� on and orienta� on of the shu� er-CCD assembly were maintained during the which holds a large number of bright course of the measurement period to avoid phase errors. stars to pleasure the eye. Tolerances in the window dimensions (D) will also aff ect the expected and actual open- The constella� on occupies 414 square ing of the shu� er. At a radius distance, r ofof 52mm52mm ffromrom thethe centrecentre ofof thethe diskdisk andand inin thethe degrees of sky and is situated just east direc� on of rota� on, the es� mate � ming error, is:is: of Sagi� arius, but sadly it is not rich in Monument marking the tropic of Capricorn deep-sky objects. S� ll, it is an easily (3) outside Polokwane, Limpopo province. recognisable compila� on, with several mnassa vol 72 nos 5 & 6 94 127 june 2013 colloquia observers page mass of 4.6 ×108 M is derived, 40% AIMS more than what was detected by VLA where, iiss tthehe pperioderiod ofof thethe pulsar.pulsar. AllAll measurementsmeasurements andand cut-outscut-outs werewere mademade withwith tolerances kept in mind to agree with the design criteria of . observa� ons. The observa� onally Title: New Views of Mercury from mo� vated pseudo-isothermal dark MESSENGER Timing data Ts() (see Fig 1) were recorded and analyzed to measure random excita� ons ma� er (DM) halo model can reproduce Speaker: Prof Catherine Johnson, i of mechanical resonance in the motor-shu� er system. The RMS error over a period of very well the observed rota� on curve Par� cipa� ng Scien� st on the MESSENGER 30 minutes was 38.3 μsec. A frequency spectrum of the � ming noise shows most of the while the cosmologically mo� vated Venue: African Ins� tute for Mathema� cal power tends towards zero with a signifi cant resonance peak at 1.78Hz. NFW DM model gives a much poorer Sciences, 6 Melrose Road, Muizenberg fi t to the data. While having a more Date: 14 May 2013 It was assumed that the excita� ons of the mechanical resonance originated from the accurate gas distribu� on has reduced Time: 19:00 hand-made disk and slight fl exing of the disk. A laser-cut disk will probably be more suit- the discrepancy between the observed Abstract: In March 2011, MESSENGER able. The supply voltage on the BLDC motor also contributes to a constant phase off set RC and the MOdifi ed Newtonian became the fi rst spacecra� ever to orbit and was calibrated before each observa� on session. Dynamics (MOND) models, this is Mercury, the innermost planet in our done at the expense of having to use solar system. Over the past two years Timing Principles unrealis� c mass-to-light ra� os and/or the spacecra� has collected, and relayed Radio Observatories doing pulsar measurements are equipped with atomic � me stand- very large values for the universal to Earth, a wealth of new data about this ards and modelling of accurate � ming is a complex process. In support of this, the pulsar constant a0. Diff erent distances or HI planet including images of the surface, community has developed a state of the art (UNIX) program (over the past 40 years) content cannot reconcile MOND with and measurements of topography, gravity, called TEMPO II which models pulsar arrival � mes up to a accuracy of 1 ns. (Hobbs et al. the observed kinema� cs, in view of the magne� c fi eld and composi� on. I will 2006; Edwards et al. 2006). For this accuracy, the exact posi� ons of solar systems bodies small errors on those two quan� � es. summarize some of our fi ndings about must be known, only available through the online JPL Ephemeris system (Markwardt. C. This result for NGC 3109 con� nues to this enigma� c planet and some of the JPL HORIZONS). However, for the proposed demonstra� on the computed (much less pose a serious challenge to the MOND challenges of ge� ng to, and opera� ng at, accurate) � ming informa� on in real-� me with a program on a PC was used and only theory. Mercury. includes the most signifi cant � ming contribu� ons.

The aim here is to determine the phase, ooff thethe pulsarpulsar atat a instanceinstance (t) related to the ... con� nued from p. 90 local UTC Clock. The phase of the pulsar can be determined from the monthly ephemeris Roy’s daughter Moira had this to say: but is only valid in the pulsar frame of reference (Lyne, A.G., et al.). An observer on Earth Besides my Dad’s astronomical hobby Jack Benne� was my godfather, although will measure a pulsar (close and his metrological career, there is not he passed away when I was s� ll young to the eclip� c) with a con- too much of interest as he led a very so I don’t remember too much besides stant change in frequency simple and humble life. His brilliant the excitement of looking at Comet due to the Doppler shi� mind and extensive general knowledge Benne� . caused by the Earth’s mo- is going to be sorely missed by us all. � on around the Sun and We will be very happy for him to be the spin of the Earth on He lived for his heaven and stars remembered and know that, as much as its axis. Keeping book of so it formed an integral part of our he hated a� en� on and drama, he would � mescales during observa- upbringing too! My sister and I have be immensely proud to be remembered � ons is also important, for many memories of being dragged out to in the astronomical world which was his Fig.5 FFT Frequency spectrum on logarithmic scales of example the most com- the telescope to observe something. love and passion. the “mechanical” � ming noise. mon � me standard, UTC mnassa vol 72 nos 5 & 6 126 95 june 2013 high-speed optical measurements colloquia is discon� nuous and dri� s with the addi� on of leap seconds (Eastman, J., et al., 2010). own Galaxy since the year 1604, the UWC Also clocks on Earth are subject to rela� vis� c eff ects and solar system gravita� onal infl u- Galaxy does contains many supernova ences will aff ect the � ming. remnants, and we see many supernovae Title: The Circumgalac� c Medium: occurring in external galaxies. I will New Fron� ers in Understanding Galaxy The general approach here is to transform the measurements to the barycenter of the give an overview of radio observa� ons Evolu� on Solar System (Eastman, J., et al., 2010). The apparent � me of an event has to be adjusted of supernovae and their remnants, Speaker: Professor Romeel Dave to be what it would be as if we were observing at the barycenter, which is the coordinate discussing interferometric observa� ons Venue: Room 1.35 of the Physics origin of all modern, precise astronomical posi� onal calcula� ons. If the source of the of Galac� c supernova remnants with Department, UWC events is sta� onary with respect to the barycenter, this gives us a steady clock with which telescopes such as the VLA (and, in Date: 27 March 2013 to measure when each event happened. future, MeeKAT) and also discussing Time: 13:00 Very Long Baseline observa� ons of Transforma� on to the rest frame of the pulsar is achieved by transforming TOA (Time extra-galac� c supernovae. I will show SKA of Arrival) pulses to the barycentre and is the sum of various � me correc� ons classically VLBI movies of supernovae 1986J and defi ned by 1993J showing there evolu� on. I will Title: KAT-7 Science Verifi ca� on: also discuss the connec� on between Hi Observa� ons of NGC 3109 - supernovae and gamma-ray bursts, and Understanding its Kinema� cs and what constraints radio observa� ons Mass Distribu� on Where ∆C contains various clock correc� ons, r iiss a vvectorector ffromrom tthehe bbarycentrearycentre toto thethe telescope, isis a unitunit vectorvector poin�poin� ngng fromfrom thethe barycentrebarycentre toto thethe pulsar,pulsar, c isis thethe speedspeed ofof can provide on gamma-ray burst Speaker: Claude Carignan light, d iiss tthehe ddistanceistance ttoo tthehe ppulsar,ulsar, D iiss tthehe iinterstellarnterstellar dispersiondispersion constant,constant, f iiss tthehe rradioadio mechanisms. Venue: Auditorium on the 2nd fl oor of the SKA South Africa offi ce frequency, ∆E� isis thethe EinsteinEinstein delaydelay comprisedcomprised ofof thethe gravita�gravita� onalonal redred shi�shi� andand � meme dila-dila- Title: A Brief History of the Coming Date: 2 May 2013 � on, ∆S� iiss tthehe ShapiroShapiro delaydelay characterisingcharacterising thethe curvaturecurvature ofof spacespace � meme nearnear thethe SunSun andand Revolu� ons: Who moved my galaxy? Time: 13:00 ∆A� isis thethe aberra�aberra� onon delaydelay asas a resultresult ofof thethe Earth’sEarth’s rota�rota� onon (Bell,(Bell, J.F.,J.F., 1996;1996; KaspiKaspi V.M;V.M; Lorimer D., 2008) Speaker: Dr Bruce Basse� , AIMS Abstract: HI observa� ons of the Venue: RW James Lecture Hall C Magellanic-type spiral NGC 3109, th Date: 15 May 2013 obtained with the seven dish Karoo Terms three and four together make up the Roemer delay ∆R� . The 4 term can be ig- nored for now which applies only to nearby sources. The Roemer delay is the classical Time: 13:00 Array Telescope (KAT-7), are used to light travel � me across the Earth’s orbit, with a magnitude of ~500 cosβ seconds, where Abstract: Astronomy, academia and analyse its mass distribu� on. Our β is the eclip� c la� tude of the pulsar (NRAO). With the Crab pulsar close to the eclip� c, Universi� es in general are facing a results are compared to what is obtained the Doppler Eff ect is signifi cant as the Earth passes through a couple of cycles during one tumultuous period which will see them using VLA data. KAT-7 is the precursor evening (depending on the season). It is also interes� ng to note that a 0.1 arc second di- revolu� onised. In 10 or 20 years they of the SKA pathfi nder MeerKAT, which rec� onal error can produce a � ming error as high as 240 microseconds and it is therefore may be almost unrecognisable with is under construc� on. The short important to keep the pulsar’s posi� on in the same coordinate frame as the ephemeris. the lenses of today. Being successful baselines and low system temperature The geometric � ming modula� on due to the Earth’s spin was compared between ob- researchers and academics in such of the telescope make it sensi� ve to serva� ons from the geocentric Earth and the (topocentric) observing site (Eastman, J., rapidly changing waters will require new large scale low surface brightness 2010). A por� on around zero Hour Angle was plo� ed (Fig. 6) and reveals a substan� al sets of skills. We will discuss the coming emission. The new observa� ons with � ming error if not corrected. changes - deep unsupervised machine KAT-7 allow the measurement of the learning, crowdsourcing, MOOCs and rota� on curve of NGC 3109 out to The dispersion delay, ccontributesontributes aatt llessess thanthan 1 μμss iinn thethe op�op� calcal bandband andand cancan alsoalso bebe more - and the strategies for adap� ng 32, doubling the angular extent of discardeddiscarded (Eastman,(Eastman, J.,J., etet al.,al., 2010).2010). TheThe ∆S� andand ∆A� termsterms hhaveave magnitudesmagnitudes belowbelow thethe to this brave new world. exis� ng measurements. A total HI mnassa vol 72 nos 5 & 6 96 125 june 2013 colloquia observers page Na� onal Research Founda� on (NRF). observa� onal viewpoint. A discussion resolu� on of the design criteria and The OAD is located at the South African of how to compare the DR with the can be omi� ed as well. The Einstein Astronomical Observatory (SAAO) in tradi� onal weak lensing approach will delay can contain correc� ons as large Cape Town. Its mission is to realise the also be addressed, based on the eff ects as 1.6 milliseconds and have to be IAU’s Strategic Plan, which aims to use in some cosmological consistency tests. included. astronomy as a tool for development. In 2012 the fi rst open Call for Proposals NASSP Having made the above transforma- was launched, focusing on three main � ons, the observed phase is calcu- areas: “Universi� es and Research”, Title: Gravita� onally Lensed Galaxies lated. The frequency of the pulsar “Children and Schools” and “Public Discovered by the Herschel Space changes since the the pulsar loses Outreach”. Eighteen projects worldwide Observatory energy through magne� c dipole ra- dia� on. By incorpora� ng the spin- have been approved for 2013 and are Speaker: Prof Lerothodi Leeuw Fig.6 Timing diff erence between topocentric down parameters from ephemeris of currently under way. The OAD is also Venue: RW James Lecture Hall C and geocentric observing. se� ng up regional nodes and language Date: 2 May 2013 one epoch, it is possible to calculate exper� se centres around the world. Time: 13:00 the phase φ(t) of the pulsar at a new This presenta� on will describe the Abstract: I will give context to the � me by the Taylor expansion ongoing ac� vi� es of the OAD and plans importance of the discovery and nature for the future. of dust- and gas-rich lensed galaxies (5) observed by the Herschel Space ACGC Observatory and a range of follow-up where = 1/P1/P isis thethe rota�rota� onalonal frequency,frequency, andand , areare thethe frequencyfrequency deriva�deriva� vesves cor-cor- observa� ons by the Southern African responding to the spin-down parameters available from the ephemeris (Bell, J.F., 1996; Title: The Dyer-Roeder Approxima� on Large Telescope and other telescopes Kaspi V.M; Lorimer D., 2008). Essen� ally, this formula calculates the integrated number and the Infl uence of the inhomo- around the world. The work that will be of cycles over period ( t - t0 ) fromfrom a arbitraryarbitrary referencereference t0 and phase φ(0) where the phase genei� es in the Cosmological Tests described is conducted in conjunc� on is refl ected in the frac� on of the cycles. Speaker: Dr Vinicius Bus� with the Herschel-ATLAS team. Venue: M111, Maths Building, UCT Measuring Results Date: 7 May 2013 Title: Exploding Stars and Their The concept was put to test on the Crab Pulsar during January and February 2013. Time: 13:00 A� ermath in Radio Observa� ons were made with the author’s SBIG ST9e CCD camera and 20cm LX200 Speaker: Dr Michael Bietenholz, telescope. (Fig.7) Abstract: The existence of HartRAO inhomogenei� es in the observed Venue: RW James Lecture Hall C The cut-out shu� er ra� o of 1:2 produced a much lower resolu� on curve compared Universe modifi es the distance-redshi� Date: 8 May 2013 to the well established reference profi le done with high speed photometers. The ex- rela� ons thereby aff ec� ng the results of Time: 13:00 pected smoothed curve was calculated by convolving the window func� on with a refer- cosmological tests in comparison to the Abstract: Supernovae are very important ence profi le of the Crab Pulsar, shown in Fig. 8. Photometric measurements at various ones derived assuming spa� ally uniform in wide range of astronomical contexts. phases of the pulsar period were performed and the resulted light curve was compared models. In this talk, I will discuss the In par� cular, both supernovae and against the calculated profi le. Dyer-Roeder (DR) approxima� on, supernova remnants are o� en bright phenomenologically characterized by in the radio. Although no supernova Due to limited sky, and bad weather, only a maximum of about 5 measurement the smoothness parameter, from an has been directly observed in our runs per evening was possible. A measurement run consists of 30 images with mnassa vol 72 nos 5 & 6 124 97 june 2013 high-speed optical measurements colloquia Date: 25 May 2013 measure distance and what is the current Time: 16:00 status of this technique. I’ll present Abstract: Stacking is a technique used some issues, ques� ons and results of in almost every fi eld in astronomy TRGB distance determina� on, based on whereby mul� ple noisy datasets Araucaria Project measurements (for example spectra or images) are co-added to improve the total signal- Title: Precise distance measurements Fig.8 The Op� cal Light curve of the Crab to-noise and allow average signals to within local Universe pulsar. The spa� al integra� on func� on of be pulled out of the data. However, Speaker: Piotr Konorski, Astronomical the strobing Windows will result in meas- tradi� onal stacking techniques can Observatory of the University of uring a smoothed light curve compare to Fig.7 The strobing assembly shown be infl exible (o� en requiring precise Warsaw (Poland) measurements by high speed photometers. mounted between the 20cm SCT and posi� on data, for example) and lose Venue: RW James lecture hall C The expected smoothed curve is based on a ST9eCCD. informa� on that could poten� ally be Date: 13 June 2013 1:2 window opening. extracted. In this talk, I will introduce Time: 15:30 30 second exposure each (total of a new approach to stacking using Abstract: Although very commonly 15 minutes) measuring a par� cular Bayesian sta� s� cs, explaining in detail used in many diff erent areas of modern phase of the pulsar. The pulsar and how one can poten� ally use hierarchical astrophysics, the great poten� al of the close companion star were not modelling to obtain informa� on about binary stars as distance indicators s� ll fully resolved in the 20-cm telescope: the underlying distribu� on from which remains underexploited. In the course consequently photometry was per- the data are drawn. I will illustrate the of Araucaria Project we are using this formed on the combina� on with the idea with some simple examples and tool to calibrate distances in our Galaxy pulsar periodically contribute to the explain the Mul� ple Block Metropolis and beyond. During my talk I will photometric fl ux. Fig.9 CCD showing pulsar OFF and ON: 15 Has� ngs algorithm I have implemented present details of the technique and try minute exposures with the stroboscope to solve the computa� onal challenges to prove that it serves as most precise All images were calibrated to standard and the author’s 20 cm / f10 telescope. that arise with this method. method for determining distances protocol without the use of fi lters. It Only 1/3 of the photons were collected within the local Universe. was found that images done above making the eff ec� ve exposure � me actu- Title: Distance measurements with Tip o -15 C and eff ec� ve exposures less ally 5 minutes. The le� -hand panel shows of the Red Giant Branch Title: The IAU Offi ce of Astronomy for than 900 seconds become unreliable the absence of the pulsar with about 9000 Speaker: Marek Gorski, Astronomical Development for photometric measurements with sample in its off -state. The pulsar, not fully Observatory of the University of Speaker: JC Maudit the current system. Evening tem- resolved but visible in the right-hand panel Warsaw (Poland) Date: 20 June 2013 o peratures were around 24 C and the resembles an accumula� on of about 9000 Venue: RW James lecture hall C Venue: SAAO Auditorium heat exchanging coolant had to be pulses from the main lobe. Note that the Date: 13 June 2013 Time: 16:00 fed con� nuously with ice. Photomet- pulsar is now almost the same magnitude Time: 15:00 Abstract: The Interna� onal ric measurements were performed as the close companion and disagree with Abstract: Infrared TRGB brightness Astronomical Union (IAU) is the largest with Astroart 5.0 (Nicolini,M., et al., other visual images of the pulsar. This is measurement enables accurate and body of professional astronomers in 2013) and the USNO-B1 Catalog. This due to the fact that most of the pulsar’s fl ux independent measurement of the the world and has set up the Offi ce method had the disadvantage that was captured while capturing only 1/3 of distance to the Local Group galaxies. I’ll of Astronomy for Development (OAD) the automa� c centroid calcula� on by the “background”. explain why and how we are using it to in partnership with the South African mnassa vol 72 nos 5 & 6 98 123 june 2013 colloquia observers page AstroArt 5.0 for the pul- Astronomical Colloquia sar companion, slightly These form an important part of a a reconfi gura� on of its circumstellar changed posi� on during research facility, o� en as a sort of pre- environment as a consequence of a the “on” and “off ” state publica� on discussion or a discussion recent fl y-by of its stellar companion, consequently overlays of an individual’s current research, RW Aur B. This interac� on stripped had diff erent background and as such it is virtually impossible away part of its circumstellar disk, areas on the nebula. A to “publish” this material. However leaving a � dally disrupted “arm” feature diff eren� al ensemble by recording the topics discussed in and a short truncated disk. We present photometry was also Fig.10 The Crab Pulsar light curve compiled from 12 the form below does indicate to those, photometric observa� ons of the performed where the hours of photometric measurements during Jan/Feb who are unable to a� end, what current RW Aur system from the Kilodegree centroid was only calcu- 2013. The Cycle was repeated for illustra� on. trends are and who has visited to do Extremely Li� le Telescope (KELT-North) lated once for the fi rst research: it keeps everyone ‘in the loop’ showing a long and deep eclipse that image of the range of images (Henden, The BLDC motor and shu� er disk performed so to speak. occurred from September of 2010 un� l A., et al. 2009; Nicolini,M., et al., 2013; above expecta� ons considering its cost. A March of 2011. The eclipse has a depth Romanishin, W., 2006). The instrumen- single desktop PC did all the � ming calcula- Also included in this sec� on are the of ~2 magnitudes and a dura� on of tal magnitudes were then further proc- � on tasks, CCD captures and telescope colloquia/seminars at the SAAO, NASSP, ~180 days. The eclipse was confi rmed essed and compared. control. The fast and accurate � ming of the UWC and the Astrophysics, Cosmology by archival observa� ons from American GPS clock played a key role in the system and and Gravity Centre at UCT, ACGC. Associa� on of Variable Star Observers About 50 photometric measurements were eff ec� vely simplifi es the concept. Also included are the SAAO Astro- (AAVSO). We suggest that this eclipse performed during January and February coff ees which are 15-20min informal is the result of a por� on of the � dally 2013 and plo� ed (Fig. 10). A best fi t through The measured light curve (Fig. 10) shows discussions on just about any topic disrupted disk occul� ng RW Aur A. The the data points was created and compared an acceptable correla� on and is therefore including but not limited to: recent astro- calculated transverse linear velocity of to the expected light curve. The expected considered to be proof of the concept as ph papers, seminal/classic publica� ons, the occulter is in excellent agreement light curve was scaled in the Y-Axis. The fl ux presented. Although there is s� ll room for educa� on/outreach ideas and ini� a� ves, with the measured rela� ve velocity of reading on the Y-Axis is not fully calibrated � ming improvements, it was shown that the preliminary results, student progress the � dally disrupted arm. Using simple and is only an approximate magnitude. (At � ming was accurate enough to synchronize reports, conference/workshop feedback kinema� c and geometric arguments, � me of wri� ng, there is s� ll an unresolved data over a two month period. It will be and skills-transfer. we show that the occulter cannot be issue where a correc� on for a 1 millisecond interes� ng if this period can be extending Editor a feature of the RW Aur A circumstellar per day � ming dri� is manually applied in to have light curve con� nuity on following SAAO disk, and we also discount other the light curve compila� on.) appari� ons. hypotheses. We also place constraints Title: Occulta� on of the T Tauri Star RW on the (projected) thickness and semi- Conclusion Addi� onally, the possibili� es of detec� ng Aurigae A by its Tidally Disrupted Disk major axis of the por� on of the arm Ini� al a� empts during 2011 and 2012 failed the pulsa� on of an object in par� cular star Speaker: Joseph Rodriguez, Vanderbilt that occulted the star. to converge in a light curve. This was mainly fi eld were inves� gated. A Flux map was Venue: SAAO Auditorium due to so� ware issues and too low photo- constructed for this purpose of 60 x 45 pixels, metric S/N ra� os. By further reducing the represen� ng the normalized photometric Date: 9 May 2013 Title: Improving Stacking Techniques o o Time: 16:00 with Bayesian Sta� s� cs CCD temperature from -5 C to -15 C with measurements of 60 selected stars in 45 im- a third stage cooling results in acceptable Abstract: RW Aur A is a classical T Speaker: Michelle Knights, AIMS ages of M1. The variability of the Crab pulsar S/N ra� os. Tauri star, believed to have undergone Venue: SAAO Auditorium shows up clearly as a ver� cal line in Fig. 11. mnassa vol 72 nos 5 & 6 122 99 june 2013 high-speed optical measurements satellite tracking Acknowledgments tried techniques in unfamiliar surround- be allowed to call on the observatory’s I would like to thank Axel Mar� n (Das Turtle ings in a foreign country. My personal astronomical specialists. Outside com- Star Observatory, Germany), for his long rela� ons with him were always of the mitments always tend to take priority standing support, especially when it comes most pleasant nature. over domes� c ac� vi� es, and I was not to photometric measurements. Thanks also prepared to see the Observatory turned to Ude Hertel, Hertel Precision Engineering For the record and as a tes� monial to into a satellite sta� on. My views were ([email protected]) for his excellent job on his ability, I would like to men� on his not sympathe� cally received, but sub- the shu� er housing and couplings. Fig.11 Flux Map. By scaling Flux values notable contribu� ons to conven� onal sequent events have only reinforced my it is easy to detect star fl uctua� ons. The astronomy since severing his connec- a� tude and I have never regre� ed the References map consists of 45 images and 65 meas- � on with ar� fi cial satellite work, e.g. his stand I took up. Bell, JF, 1996. “Radio Pulsar Timing”, e-Print: ured stars/image. The Crab pulsar is in me� culous edi� ng of the published pro- arXiv:astro-ph/9610145v1, 4-5. star posi� on 31. ceedings of the symposium on Magne� c Returning to Astronomy Cadez, A, et al, 2003, “CCD based phase resolved and Related Stars (1965) and his chapter We entered into whole-hearted coop- stroboscopic photometry of pulsars”, e-Print: arXiv:astro-ph/0303368v1, 1-4. on Stellar Evolu� on in Introduc� on to era� on with the IGY ac� vi� es with the Dhillon, VS, et al, 2007, “ULTRACAM: an ultrafast, triple-beam CCD camera for high-speed Space Science (Ed. Wilmot N. Hess), one understanding that it was limited to the Astrophysics”, MNRAS(2007), 378, 2. Eastman, J, et al, 2010, “Achieving Better Than 1 Minute Accuracy in the Heliocentric and of the most lucid surveys at the present period 1957-1958 and that therea� er Barycentric Julian Dates”, e-Print: arXiv:1005.4415v3, 1, 2-7, 6, 7. � me (1959 -1960). we would revert to our normal astro- Henden, A, et al, 2009, “The AAVSO CCD Observing Manual”, e-Print: AAVSO(2009), 23. nomical ac� vi� es. This a� tude also met Hobbs, GB, et al, 2006, “TEMPO 2, a new pulsar-timing package”, MNRAS (2006),(2006), 369, 1, The Baker-Nunn sta� on with some cri� cism. At one of the last Kaspi VM, 1994, “High-Precision timing of millisecond pulsars and precision astrometry”, http: Shortly before the beginning of the IGY, mee� ngs of the Satellite Commi� ee I //hdl.handle.net/2014/33528, 3, 4. great pressure was brought on me to expressed the view that a� er the IGY sat- Lorimer D, 2008, “Binary and Millisecond Pulsars”, Living Rev. Relativity(2008) - ISSN 1433- agree to the Union Observatory under- ellite work should be the responsibility of 8351, 11, 36, 37. Lyne, AG, et al, 1993, “Jodrell Bank Crab Pulsar Timing Results, Monthly Ephemeris”, MNRAS, taking the management of the Baker- specialists and proposed that a small sat- 265, 1003, http://www.jb.man.ac.uk/~pulsar/crab.html. Nunn sta� on. The inducement was even ellite bureau should be created to retain Straubmeier, C, et al, 2001, “OPTIMA: A Photon Counting High-Speed Photometer”, Experimental held out of the Observatory acquiring the services of one or two people who Astronomy, 11, 4, 5. the camera at the end of the IGY and had shown special ap� tude. This pro- Yedamale, P, 2003, “Brushless DC (BLDC) Motor Fundamentals”, Microchip Technology Inc, using it for purely astronomical purposes, posal was received almost with horror. AN885, 1. (as I once remarked at a mee� ng of the Satellite Commi� ee, the belief seemed When Dr Hynek expressed his surprise Related online sources: to be prevalent that all ar� fi cial satellites at the decision to disband “the world’s Barycentric Julian Date, http://astroutils.astronomy.ohio-state.edu/time/bjd_explanation.html Closed-cell PVC, http://en.wikipedia.org/wiki/Closed-cell_PVC_foamboard would obediently tumble to Earth on 31 foremost Moonwatch team” I countered How to read the JPL Ephemeris and Perform Barycentering, http://asd.gsfc.nasa.gov/ December1958 – failure to realize that by telling him that the sugges� on that Craig.Markwardt/bary/ we were witnessing the birth of a new we should carry on indefi nitely, was like Jodrell Bank Crab Pulsar Timing Results, Monthly Ephemeris, http://www.jb.man.ac.uk/~pulsar/ era.) I insisted that the proposal would shou� ng to a hundred yard sprinter as crab.html be acceptable only on condi� on that he breasted the tape “now carry on for JPL HORIZONS - solar system data and ephemeris service, http://ssd.jpl.nasa.gov/?horizons the camera sta� on had its own Offi cer- a mile!” We had exerted ourselves to Nicolini,M, Astroart MSB So� ware, h� p://www.msb-astroart.com/ in-Charge as a branch of the Observa- the utmost and given of our best as loyal Nilsson, R, High-Speed Astrophysics: Chasing Neutron-Star Oscilla� ons, tory, recruited its own staff , and in the members of an interna� onal team, but http://www.scribd.com/doc/44046701/High-Speed-Astrophysics-Chasing-Neutron-Star- event of unfi llable vacancies, would not we had had enough. mnassa vol 72 nos 5 & 6 100 121 june 2013 IGY reminiscences observers page Oscilla� ons with three axes, one NRAO, Pulsar Timing Tutorial, www.cv.nrao.edu/course/astr534/PulsarTiming.html of which permi� ed Romanishin, W, 2006, An Introduc� on to Astronomical Photometry Using CCDs, h� p:// tracking along the www.physics.csbsju.edu/370/.../OU.edu_CCD_photometry_wrccd06.pdf plane of the orbit. The AAVSO CCD Observing Manual, h� p://www.aavso.org/ccd-observing-manual The Sputnik was Van Staden, A, GPS E2 Clock, h� p://www.e� ming.co.za then followed � ll it passed between two suitable stars. The GRB130427A detected by Supersid monitor binoculars were then le� in posi� on and Brian Fraser, Henley on Klip the stars iden� fi ed at leisure. For many years amateur astronomers Solar Flares have been using simple radio receivers Solar fl ares are classifi ed using the let- Fainter American to monitor the eff ects that solar fl ares ters B, C, M and X with the B class being satellites have on the Earth’s ionosphere and rela� vely mild and quite common during The three-dimen- The Johannesburg Moonwatch team set up their Apogee telescopes the knock-on eff ect that this has on the � mes of high solar ac� vity. Conversely, the sional slide-rule was on the grounds of the Union Observatory next to the Innes dome. propaga� on characteris� cs of low fre- X class fl ares are the rarer and much more adequate for naked Note the model or three-dimensional slide-rule in the background. quency radio sta� ons. These systems energe� c variety. In order for a fl are to be eye Sputniks, but (CSIR Archives) are variously known as SES recorders picked up by a small SID receiver it needs was not suffi ciently accurate for faint South African Witchdoctor (Sudden Enhancement of Signal) or to be around class C5 or brighter. M class American satellites, although even in It was at the braaivleis to celebrate the SID recorders (Sudden Ionosphere Dis- fl ares show up very nicely. NASA publishes these cases it was useful for showing opening of the Baker-Nunn sta� on that turbance) and operate at frequencies a daily summary of all sorts of events hap- the general situa� on, and for rough a set of predic� ons for SAO cla� ered out around 20 kHz. Stanford university pening on the sun and these can be seen checking. For the American satellites it of the telex, ending with the greatly ap- have developed a system that does not at h� p://www.swpc.noaa.gov/� pmenu/ was necessary to use quite sophis� cated preciated compliments: “but rely heavily require a radio receiver and u� lizes indices/events.html computa� onal methods for reducing on Finsen’s predic� ons”. Also appreciated the power of a sound card in a small observa� ons, correc� ng the orbits, and was Cameron’s generous acknowledge- computer, which they call the Supersid. As we approach solar maximum, predicted compu� ng the predic� ons. Though they ment of the value of my predic� ons. On So� ware supplied monitors up to ten to occur in 2013 or 2014, the number and were based on well-known dynamical at least one occasion, so he told me, he transmi� ng sta� ons on a con� nuous intensity of solar fl ares is increasing. Dur- procedures (certainly well-known to a ended a telexed report to SAO of success- basis. The radio sta� ons that are moni- ing May 2013 there were a number of M double star specialist!) it was necessary ful observa� ons with the words “Predic- tored are used by the military to com- class fl ares and even one X class fl are asso- to invent and improvise, and look for all � ons by South African Witchdoctor” and municate with submarines out at sea. ciated with a very ac� ve sunspot group. possible shortcuts. It was very heavy he even presented me with a plaque with It is only the carrier wave strength that work, at the crack of dawn, day-in and the legend “South African Witchdoctor”. these receivers are interested in. SID re- Gamma Ray Bursts day-out. The accuracy of the predic� ons corders run 24 hours a day, require very There had been a long running debate was quite pleasing: the error in � me was I always felt that the diffi cul� es under li� le maintenance and work whether it about whether SID sta� ons would be a ma� er of seconds rather than minutes, which Cameron had to work were not is rainy or clear. All they require is an able to detect Gamma Ray Bursts (GRB’s) and in al� tude of minutes of arc rather understood: beginning a whole new antenna, a small amplifi er circuit and an and this argument was se� led in 2001 than degrees. project involving sophis� cated but un- old computer with a sound card. when Danie Overbeek and Dominic Toldo mnassa vol 72 nos 5 & 6 120 101 june 2013 observers page satellite tracking reported the detec� on of a gamma ray On 27 May 2013 the most violent GRB The public demand for informa� on was asked why they did not let us have the burst (GRB010222) on a receiving sta� on ever detected, at 94 billion eV (94 GeV), so insa� able and the resul� ng phone conven� onal parameters that they must that they were running in Edenvale. This was picked up and monitored by the GRB calls from press and public for predic- be using – we could turn them into regu- was the fi rst recording of a GRB by any network. An amateur astronomer, Patrick � ons so con� nuous and disrup� ng that lar orbital elements ourselves. No, they amateurs anywhere in the world. Wiggins, photographed it from Utah, USA. the only remedy was to phone predic- couldn’t do it. It was keenly studied � ons for the next day (or days, when by many professional weekends followed) to SAPA before 10 Sputnik fatality! observatories. It was am. I therefore had to be in the offi ce It may not be remembered that the also picked up by a SID as early as 5 or 6 am every day to reduce Sputniks resulted in at least one fatality recording sta� on in the observa� ons of the night before, in South Africa. This happened because Henley on Klip, RSA, and correct the orbit, and prepare predic- newspapers some� mes did a li� le shows up very strongly � ons for the major centres. This a� er predic� ng on their own – they no� ced on graphs from two two or even three observing sessions that o� en there were two passes in the diff erent radio sta� ons. during the night: I o� en had to set my evening separated by 100 minutes or so. Because the transmit- alarm twice during the night. I think I am What they did no realize was that their � ng sta� ons are located right in saying that I took part in every predicted second pass was invisible as in diff erent geographic observing session – except of course the satellite was then in the Earth’s loca� ons the signals when I went to Moscow for the IGY and shadow. On one such occasion a man pa� erns received look IAU mee� ngs. on the roof or balcony of a block of fl ats diff erent. However they leaned over too far in his a� empt to both show the event, I think the observing methods and the see the invisible spectacle, and fell to albeit in diff erent ways, ve� ng of observa� ons must have been his death. around 9 UT. rather sound, for in Moscow I was inter- viewed by a member of the Russian or- I found then that the easier and most suc- ganiza� on who wanted to know exactly cessful way of observing a Sputnik was to how we made such accurate observa- mount a pair of binoculars on a tripod � ons.

Incidentally, the Russians at the IGY mee� ng were very cagey about releasing the conven� onal orbital elements of their Sputniks. They claimed that their computers were not capable of doing this, and that all they could supply were predic� ons. This led to rather GRB 130427A as recorded at Sta� on NAA (top) and NPM heated protests from foreign- (bo� om) on 27 April 2013. ers present, including myself. I Ar� sts impression of Sputnik-1 in orbit. mnassa vol 72 nos 5 & 6 102 119 june 2013 IGY reminiscences satellite tracking Naude did a na� onal broadcast on the Sputnik Moonwatch in in the course of which he read my statement South Africa: – without acknowledging its source! 1957-1958

I shall not easily forget the relief I felt when Jan Hers we fi rst saw Sputnik 1 shoo� ng across the This posthumous pub- sky in good agreement lica� on of an ar� cle by The author explaining the behaviour of orbi� ng satellites to J with my predic� on. For Jan Hers (see obituary Churms (le� ) and JA Bruwer using the model or three-dimen- some days therea� er in MNASSA Vol. 69 nos sional slide-rule which he constructed. (CSIR Archives) The Pretoria Moonwatch team manning Apogee SAPA phoned the TASS 9 & 10) recounts South telescopes, observing from the CSIR roo� op. to sit down and sort things out. No hard predic� ons through to me, which was a Africa’s involvement in informa� on from overseas – only the great help. what can be called the beginning of the three methods were proposed: TASS predic� ons that at such and such Space Age. The launch of Sputnik 1 on � mes the Sputnik would be “over” such Quest for accurate predic� ons 4 October, 1957, during the Interna� onal 1 by radio, and such ci� es (none of which were in For the three-dimensional slide-rule Geophysics Year (IGY) caught most of the 2 photographic, South Africa). And of course the whole I bought the largest terrestrial globe world by surprise, primarily because the 3 visual. of South Africa wanted to know when it obtainable locally, and converted it in United States was planning to put about would be visible here. Over the week- my workshop. It was calibrated with six satellites into orbit during IGY. Africa Radio tracking would obviously depend end I locked myself in my workshop and care so that one could set it with con- was the fi rst land mass crossed a� er a on whether usable radio signals could be made a small and rough model of Earth ven� onal astronomical orbital param- rocket was launched from the US and obtained from the satellites. As this would and satellite orbit. With the help of this eters, and there was even provision for this was the mo� va� on for South Africa’s depend on many factors which were as and the TASS predic� ons I was soon determining the � me of entry into the involvement. Jan Hers’ detailed memo- yet unknown, much emphasis was placed able to see the general nature of the Earth’s shadow. This model gave � mes, ries of these � mes makes for interes� ng on photographic and visual tracking. This orbit (period inclina� on, etc.) and with a al� tudes and direc� ons with suffi cient reading. would in any case be necessary in the case rough guess at the rate of precession of accuracy for naked eye Sputniks, correct of satellites without radio transmi� ers, or the node, I was able to forecast fairly ac- to a minute or so in � me, and about 5° Around 1956 it became known that the with transmi� ers which had failed, rocket curately when the Sputnik would fi rst be or so in al� tude when fairly high in the United States of America, as part of its casings, etc. It was an� cipated that visual visible from South Africa. I accordingly sky, and be� er when near the horizon. I contribu� on to the Interna� onal Geo- observing methods would probably be the wrote a short statement, and I think it remember occasions when we observed physical Year, would a� empt to put a only ones fl exible enough to observe the was on the next day that Prof SP Jackson (and photographed) a Sputnik over number of ar� fi cial satellites (possibly very early stages of a satellite’s journey, came to the offi ce to see if we could tell Tristan da Cunha and Madagascar. The a maximum of six) in orbit around the and the only ones available to observe a him anything defi nite. I showed him my model was also helpful for correc� ng the Earth. If these were to serve a useful sci- dying satellite. They might be essen� al statement and he asked if he could take orbital elements using the observa� ons en� fi c purpose, accurate tracking would for determining the preliminary orbits it away, which he did. On that night Dr of the night before. be necessary, and in order to do this and ephemeredes necessary for aiming mnassa vol 72 nos 5 & 6 118 103 june 2013 moonwatch: 1957 - 1958 satellite tracking how to build the small telescopes which were considered most suitable, were pub- IGY Reminiscences lished in the Bulle� n for Visual Observers of Satellites, which was issued as a sup- WS Finsen plement to Sky and Telescope from July 1956 onwards. Numerous teams were registered in the U.S.A. and eff orts were Dr William Stephen Finsen was Chief As- made to recruit as many as possible in sistant of the then Union Observatory in other countries. Johannesburg. In 1956 he became Un- ion Astronomer and eventually the one First Observing Teams in South Africa and only Republic Astronomer when In South Africa it was realized that this South Africa became a Republic in 1961. country would be the fi rst land mass to These reminiscences are interes� ng be crossed by a satellite launched from for the background detail he gives, see The IGY logo shows a satellite orbi� ng Earth Florida in a south-easterly direc� on, and ar� cle in this issue on “Moonwatch in - very few people recognized the signifi cance of this. The author busy checking on the � me observa� ons made in South Africa would South Africa”. His remark that he “. . . service which he developed at the Union therefore be par� cularly important. The was not prepared to see the Observa- (Director of the Weather Bureau), and Observatory in Johannesburg. project was disclosed at an early stage at tory turned into a satellite sta� on . . .” there was visible surprise on the part of the Union Observatory in Johannesburg came a� er the Interna� onal Geophysi- those present at my urging that “sputnik- the more accurate photographic Schmidt with some of the observatory’s amateur cal Year (IGY) was over. His feelings ery” was to be taken seriously. Dr Schu- (“Baker-Nunn”) telescopes (see MNASSA associates, all of whom were ac� ve and were almost prescient, echoing those of mann even suggested that as I appeared Vol. 71 Nos. 5 & 6 p. 103). experienced observers. It was felt that many of the astronomical community to know so much about the subject I Johannesburg and Pretoria would prove today, who don’t see astronomy being should give a lecture on it! I replied by Amateur Observers to be ideal observing sites because of: a “space science”! Editor saying that I had already exhausted my It was felt that this work could best be knowledge of the subject. Dr Schumann: done by teams of amateur observers in 1 the very good climate, Although the symbol or badge of the “You are very honest!” various parts of the world, who would 2 their large popula� ons, from which Interna� onal Geophysical Year (on let- be asked to provide themselves with a suffi cient number of good observers terheads, etc.) was a satellite orbi� ng At a later mee� ng I warned of the im- small, inexpensive, portable telescopes, might be drawn, the Earth (Fig. 1), the South African IGY minent launching of Russian satellites. It just powerful enough to observe the kind 3 the close proximity to astronomical Commi� ee had apparently not taken this was Major Cockbain, of Defence Intelli- of satellite ini� ally contemplated, viz. a observatories, almost essen� al for or- very seriously and had perhaps regarded gence, who told me a� erwards that they 20-inch diameter (0.5 m) sphere. The ganiza� onal and scien� fi c guidance and the successful launching of satellites as a had also got wind of it. project which was given the code name support. fl ight of fancy. At any rate, no funds had MOONWATCH, was organized and coor- been set aside for possible par� cipa� on Sputnik 1 launched dinated by the Smithsonian Astrophysical Shortly a� erwards Moonwatch teams by South Africa. As far as I know, I was As I remember, it was on a Saturday Observatory in Cambridge, Mass., which were formed in both Johannesburg and the fi rst to draw a� en� on to the serious morning that the news broke of the was also responsible for the precision Pretoria, under the respec� ve leadership prepara� ons that were being made for launching of Sputnik 1. The offi ce was photographic tracking programme. De- of Dr Charles N Williams and Mr Roy FN this project overseas. This was at a small bedlam – phone ringing con� nuously tails on how to start observing teams, and Smith, and these were registered with mee� ng convened by Dr TEW Schumann (almost), reporters etc. No � me at all mnassa vol 72 nos 5 & 6 104 117 june 2013 moonwatch: 1957 - 1958 satellite tracking It was recognized, however, that profes- End of IGY Moonwatch Headquarters in February submission to the S.A. Na� onal Commit- sional and amateur astronomers who On 13 January 1959 the leader of the Jo- 1957. These two teams, together with tee for the Interna� onal Geophysical Year, were interested might, in special cir- hannesburg Moonwatch team informed one in Hawaii, were the fi rst ones regis- IGY. cumstances, be willing to make certain the Secretary of the S.A. Na� onal Commit- tered outside con� nental associates. observa� ons on request. For this reason tee that the team terminated its ac� vi� es Dr Evans, who by now was taking an it would be desirable to leave some equip- as from 31December 1958, and was now Meanwhile, in Cape Town, Dr David Evans increasingly ac� ve part, was invited to ment at each centre. completely disbanded. All members of had been inves� ga� ng the possibility of a� end a mee� ng of the Steering Com- the team had been sounded and the deci- organizing, through the Astronomical So- mi� ee of the SANC on 26 March 1957, sion was unanimous. ciety of Southern Africa, a suitable team where the ma� er was discussed further. of amateur astronomers, to be sta� oned Unfortunately details of the new space At the Union Observatory the policy be- at the Cape Observatory, but he had de- developments had only reached offi cial came that normal astronomical func� ons layed further ac� on un� l more was known circles at a late stage, when prepara� ons would once again enjoy priority. Satellite regarding the availability of op� cal equip- for other ac� vi� es in connec� on with the observa� ons would s� ll be made in all cas- ment. IGY had already been in progress for a es of genuine emergency, not as a “Moon- considerable � me, so that it was diffi cult watch” team, but with the help of half a Op� cal Instruments to fi nd addi� onal funds. Nevertheless, a dozen or so experienced amateurs per- In Johannesburg, however, Dr Williams sum of £500 was made available to the manently associated with the observatory. and the Moonwatch Commi� ee members three Moonwatch teams in Johannesburg, However, when a request was received for were busy making inves� ga� ons regarding Pretoria and Cape Town, to buy compo- the return of the Apogee telescopes, this supplies of op� cal components, and had nents according to schedule (2). It was ac� vity of necessity had to cease. drawn up a schedule of three alterna� ve agreed that Dr Evans should be invited to possibili� es. serve as Coordinator for the Moonwatch The Bloemfontein team was disbanded programme with the assistance of Mr J but at Pretoria and Cape Town small 1 15 complete instruments, wide angle: Churms of the Union observatory as As- teams con� nued to func� on on a limited £400 approx. sistant coordinator for the Transvaal. The basis, in a manner which has proved to be 2 Components for 15 instruments, wide Coordinator was to supply specifi ca� ons a striking vindica� on of the predic� on that angle: £100 of the op� cal components to the CSIR, Honourary ASSA member Cliff Turk at future observing would be done by very 3 Components for 20 simpler instruments, who would take responsibility for ordering the Cederberg Observatory with the small, closely integrated, teams of profes- narrow angle: £36 them from overseas. Apogee telescope used by Dr W Hirst. sional or semi-professional observers. The following addi� onal comment was Visit of Dr Karl Henize Table 2: Total number of Visual Satellite Observa� ons made in South Africa as reported to made: “We have commi� ed ourselves to Dr Karl Henize of the SAO visited South Moonwatch Headquarters during 1957-1958 the programme, and it is our inten� on to Africa at the beginning of April 1957 and proceed with the plans in any event. Fail- a mee� ng was held at the Union Ob- ing outside fi nancial support, this will limit servatory on 2 April, to discuss the various us to schedule (c)” Moonwatch aspects. Present were Dr WS Finsen, Dr SP Jackson, Dr Karl Henize, Dr This memorandum was forwarded to Mr DS Evans, Messrs J Churms, J Hers, DG DG Kingwill at the CSIR on 11 March, for Kingwill and RFN Smith. mnassa vol 72 nos 5 & 6 116 105 june 2013 moonwatch: 1957 - 1958 satellite tracking In the memorandum drawn up a� er the for two sta� ons, having higher magnifi ca- especially at meal-� mes or in early morn- assistance will be discouraged – prac� cally mee� ng it was stated that the South Afri- � on and a smaller fi eld (and hence requir- ings in winter. No long-term reliance can every observatory can count on the help can amateur astronomers, both individu- ing more observers). This would defi nitely be placed on such assistance. of seasoned, experienced helpers who are ally and as members of the Astronomical not cons� tute a means of equipping an professionals in all but the name. Society of Southern Africa, were willing ordinary sta� on, and must be regarded On the other hand, the importance of to assist in making visual observa� ons on as a supplement. Decision was to accept visual observa� ons to keep day-to-day The very clear implica� on, therefore, was the lines of the MOONWATCH system pro- such equipment if and when it should ar- track of satellites has exceeded all ex- that in future the visual observa� on of posed by the USA authori� es. The Direc- rive, but not to vary the se� led policy on pecta� ons, especially when carried out satellites should be a recognized profes- tors of the Observatories at Johannesburg, that account. in in� mate associa� on with the camera sional ac� vity, which should not be le� Pretoria and Cape Town were willing to sta� on. The emphasis is no longer on ini- to a group of amateurs or to the nearest grant site facili� es and technical advice in On 20 May a further mee� ng of the � al “acquisi� on” of satellites followed by astronomical observatory. However, in general to assist the eff orts of the South Satellite Management Commi� ee was long rus� ca� on � ll they “spiral to Earth” many circles this point was not well un- African amateur astronomers. held at Dr Finsen’s house, where it was but on day to day monitoring with the derstood. Dr J Allen Hynek, the Associate agreed that a Moonwatch team would highest possible precision. Predic� ons Director of Op� cal Tracking, during his It was also stated that “all correspondence must therefore be as accurate as pos- visit to South Africa and to the Union ob- with the USA authori� es will pass through sible, but on the other hand only a few servatory at the beginning of September Dr Evans to the U.S. Coordinator for observers will be required, as a complete 1958, expressed shocked surprise when Moonwatch, Dr Leon Campbell junior – a “fence” is no longer necessary. In short, it told that the Johannesburg Moonwatch decision rapidly overtaken by later events. will be a professional, as dis� nct from an team intended to disband at the end amateur ac� vity. of the year, and that the Observatory Ini� ally three Moonwatch teams were to intended to go back to some astronomy. be organized as shown in Table 1 below. In this connec� on it is signifi cant that in a “The world’s foremost Moonwatch team recent Smithsonian compila� on of satel- qui� ng? Never!” It was not considered desirable to try to lite observa� ons, the work of established encourage the forma� on of Moonwatch observatories tends to overshadow that On the other hand, at the mee� ng of the groups in other South African centres, as of amateur Moonwatch teams. The no- South African Satellite Management Com- it seemed probable that the best results table success of South African Moonwatch mi� ee on 30 October 1958, there seemed would be obtained by concentra� ng on teams is only apparently an excep� on, our to be a strong feeling that op� cal observa- three teams. Dr Henize reported that the An example of an early Moonwatch teams have been built round a solid pro- � ons were of rela� vely li� le use, and that U.S. Navy might supply op� cal equipment telescope. fessional core. in future whatever funds were available should be used for radio tracking only. In Table 1: The ini� al Moonwatch teams. The conclusion seems inescapable that spite of the fact that cables cos� ng some “Moonwatch”, as originally visualized, is £1800 per month were s� ll being sent to Johannesburg Team leader: Dr CN Williams Deputy: Mr J Churms moribund. The team should be dropped. the Union Observatory, no further funds Loca� on: Grounds of the Union Observatory Visual observa� on, rendered more effi - would be available for outgoing cables Pretoria Team leader: Mr RF Smith cient by improved predic� on and methods, repor� ng observa� ons, and the South Deputy: Mr N van der Vlist Loca� on: Grounds of the Radcliff e Observatory will be largely a professional ac� vity cen- African Na� onal Commi� ee could not be Cape Town Team leader: Dr DS EvansEvans tred at the satellite ins� tu� on or camera responsible for any further charges relat- Deputy: Mr WP Hirst Loca� on: Grounds of the Royal Observatory sta� on. This does not mean that amateur ing to the Moonwatch programme. mnassa vol 72 nos 5 & 6 106 115 june 2013 moonwatch: 1957 - 1958 satellite tracking predic� ons – produced the hard way, for the next day diff ered by more that 10° were received on 21 May, and this made without the aid of electronic computers in al� tude. This was too much to cover it possible for prototype telescopes to – had shown that this was en� rely possi- by either of the two groups of apogee be built at both Johannesburg and Cape ble. Good predic� ons would lead to good telescopes and diffi cult for both groups Town. Unfortunately the others which observa� ons, which in turn would lead to since the distance was also uncertain. A were to be shipped by air freight were be� er predic� ons. posi� on was therefore computed on the very slow in coming, and it was not un� l basis of a rough Minitrack observa� on September that it was learned that they Last words to Mr Robert Cameron, As- made the previous day (which gave � me had in fact been shipped. However, it tronomer-in-Charge at the Olifantsfontein only). The possible range in al� tude was was fi rmly believed that no satellite Satellite Tracking Sta� on , in a le� er to divided between the two teams, Pretoria would go up before 1958. At a mee� ng Dr CN Williams: “Recent correspond- taking the northern and Johannesburg of the Satellite Management Commit- ence from the Smithsonian Astrophysical the southern half, in the expecta� on that tee held on 24 September it was noted Observatory indicates that in addi� on to one of the teams might be able to see the that components had not been received, being the fi rst in the world to photograph satellite. And so it happened that when and it was agreed that as soon as they An early Moonwatch telescope, made at 1958 Alpha, our telescope at Olifantsfon- the satellite passed very nearly through were to hand a mee� ng of team leaders the Union Observatory for about 15 shil- tein was the fi rst to get the Delta 2 a� er the centre of the northern half, Roy Smith, lings! (CSIR Archives) should be arranged in Bloemfontein – a it had separated from Delta 1. Further- of the Pretoria team (which by then con- mee� ng which never took place. more, we had more Delta 1 photographs sisted of four observers) became the fi rst be set up at Bloemfontein, under Dr than any other sta� on by a considerable in the world to see Explorer lV. J Stock, who was at that � me at the It was at this same commi� ee mee� ng margin. In a� aining these successes, we Boyden observatory. Regre� ably a that Dr Finsen men� oned that he had were loca� ng the satellites almost en� rely New ideas on Moonwatch request from Port Elizabeth had to be received informa� on that the Russians, on predic� ons made by Dr Finsen using The methods which had been developed turned down as no funds for further too, were planning to launch a satellite. the Johannesburg-Pretoria Moonwatch in Johannesburg were clearly stated in equipment were available. Since the This was greeted with some incredulity observa� ons. The amazing world record a memorandum by Dr Finsen, dated 2 cost of eyepieces had gone up by 50%, by the other members present, but a� er number of turnouts for Moonwatch ses- July 1958, of which the following is an the number would have to be reduced the mee� ng one of the other persons sions held by the Johannesburg team, extract: from 80 to 60, i.e. each team would be present admi� ed privately that he had combined with the large number and high en� tled to 15. In the mean� me a simple received similar informa� on. reliability of the observa� ons deserves “Moonwatch may be regarded as in the Moonwatch type telescope had been the highest commenda� on as a very im- mel� ng pot. In its original concep� on as built at the Union Observatory at a cost Sputnik l and ll (1957 Alpha and Beta) portant contribu� on to the Interna� onal a technique for “acquiring” faint satellites of about 15 shillings. The fi rst Russian satellite burst upon an Geophysical Year.” out of the blue, it must be regarded as unsuspec� ng world on 4 October 1957, almost an out-and-out failure. The dura- The Johannesburg team leader reported upse� ng most of the carefully made 1958 Epsilon – Explorer IV � on of a “watch” is too long and the large that by May 1957, 16 observers had plans. None of the special tracking sta- Launched on 26 July 1958, Explorer IV number of observers required compels been recruited, while on 12 June Cape � ons planned for South Africa were as seemed to be temporarily lost. The Jo- one to rely on raw inexperienced amateurs, Town had recruited 40, and Bloemfon- yet in opera� on, and even the Moon- hannesburg and Pretoria teams combined incapable of making reliable observa� ons, tein as many as 75. watch teams were unequipped. What all their telescopes to cover an arc of ap- or dis� nguishing between meteors and they could do was to bring out every proximately 50° on 27 July, but nothing satellites. Their enthusiasm is short-lived Two sets of telescope components which available pair of binoculars or small tel- could be seen. Predic� ons from overseas and is not resistant to frequent call-outs, had been ordered to be sent by air freight escope, and to start observing the satel- mnassa vol 72 nos 5 & 6 114 107 june 2013 moonwatch: 1957 - 1958 satellite tracking Stresses and Strains did not seem to be speaking the same lan- It was now becoming clear that the pro- guage. The Johannesburg team, having cedures for visual observing had strayed produced a far greater number of good a considerable distance from the Moon- observa� ons that all the other sta� ons watch scheme as originally conceived. combined, felt that it was hardly fair that Instead of observing a satellite for a few it could only get, a� er a great deal of argu- nights only, at the beginning and at the ment, one tenth of the instruments which end of its life, the demand was now for al- had been freely allocated to Cape town most con� nuous night by night observing, and Bloemfontein. The Cape Town team apparently not much diminished by the was justly proud of its achievement of be- Sputnik 2 was launched on 2 November fact that the precision tracking sta� ons ing the fi rst to observe 1958 Alpha, against Sputnik 1, launched on 4 October 1957, 1957 and carried the fi rst living creature were now fully opera� onal. Observers great odds, but Johannesburg replied that was the fi rst satellite placed in Earth orbit. into space, a dog named Laika. In 2002 it were beginning to get � red, o� en discour- with similar instruments, and with Dr Fin- was revealed that Laika died several hours aged, and were star� ng to withdraw. Tem- sen’s predic� ons, they would have done as a� er launch, from stress. lites whenever and wherever they could pers were wearing thin. This must have well, if not be� er. be seen. The author was on his way Early Predic� ons been par� cularly frustra� ng to the Moon- to Cape Town at the � me, and found Accurate predic� ons became an urgent watch Coordinator in Cape Town who was Furthermore, many of the Johannesburg himself at the Royal Observatory on necessity almost immediately, because trying to maintain some semblance of the observa� ons had not been made at the the evening of 7 October. As there was informa� on from abroad was mainly in original organiza� on. Observatory, but at the homes of enthu- no one else ready to help with this task, the form of Russian press handouts, vague sias� c amateurs, or wherever a suitable he was asked to man the telephone, and o� en unreliable. It proved impos- However, this was no easy ma� er, for instrument was available. In the view of to spend the next hour or so trying to sible to obtain orbital elements and the Cape Town was rather out on a limb, and Dr Evans such observa� ons, which had answer and uninterrupted stream of Russian news would merely state that at far removed from the centre of ac� vi� es. not been made at the central, registered, reports and enquiries from all over the such and such a � me the satellite would O� en the northern and southern teams observing site, were more or less a waste peninsula. be over, say, Delhi or Tokyo. Radio signals Apogee tel- of � me. However, experience had shown were received from the satellite, but it escopes in Cape that this was by no means the case. Very In Johannesburg a small model was con- was soon realized that what was seen was Town. The Apo- o� en such an observa� on had turned structed in great haste, to help explain not the satellite itself, but the much larger gee telescope was out to be the only one available from the mo� on of a satellite to the press rocket casing. Predic� ons for the visual a great asset to anywhere in the world. In such cases any and the general public. Also as an aid object would therefore have to be made the Moonwatch observa� ons became a key observa� on. programme for in determining the mo� on of the satel- from visual observa� ons, and the ini� a- several reasons, lite around the Earth, and for predic� ng � ve to do this was immediately taken by one of which was The tendency at Johannesburg was, in where and when it might be visible. Dr Finsen. From 9 October onwards the that it had a hori- fact, to move away from the idea of a long Some � me later this idea was further de- predic� on of satellite posi� ons, from lo- zontal eyepiece “fence” of telescopes, with a large number veloped by Dr Finsen into a larger Earth cal observa� ons and from any other data which enabled of observers watching small sec� ons of and satellite model which became in which might be available, became a full long periods of the meridian almost at random, but to eff ect a kind of three-dimensional slide � me ac� vity. Daylight hours were spent uninterrupted rely on a small dedicated group of skilled observation. Im- rule, of suffi cient accuracy to provide compu� ng (using an electro-mechanical age: Peter Smits observers and – very important – accurate predic� ons for visual observers. calculator: this was long before the days predic� ons. Experience with Dr Finsen’s mnassa vol 72 nos 5 & 6 108 113 june 2013 moonwatch: 1957 - 1958 satellite tracking at the Union Observatory diff ered from the was needed if the satellite was to be pho- of electronic calculators) and evenings being forwarded to Dr Evans in Cape locally computed value by 23.5 seconds in tographed. Errors in the predic� ons from – and later, early morning hours – were Town, where they were combined with � me and only 1 minute of arc in al� tude, a the U.S.A. o� en exceeded the maximum spent looking for satellites and, as accu- the Cape observa� ons and then transmit- quite astonishing achievement. allowed. When the fi rst successful pho- racy increased, also fi nding them. ted to Cambridge, U.S.A., but no useful tograph was obtained on 18 March – the predic� ons were received in return. It Apogee Telescopes for Johannesburg and fi rst in the world – this was due en� rely It was already becoming obvious that the seemed clear that the day when each new Pretoria to the computa� ons made at the Union observing procedure diff ered consider- observa� on would be fed into a computer, Representa� ons made through the Na- Observatory. ably from what had been visualized in the to produce a corrected orbit and a new � onal Commi� ee of the IGY fi nally bore original “Moonwatch” programme, for predic� on, was s� ll very far off . Was there fruit. Around the middle of February The number of observa� ons of 1958 of which the instruments were in any case anyone who really needed the results? approval was given for some of the Apo- Alpha, reported to the Satellite Manage- not yet available. In the fi rst place, the gee Telescopes, which had been sent to ment Commi� ee in the associates by 16 objects now seen were much brighter “Spacetrack” Predic� ons Bloemfontein but not yet installed, to be April 1958 was as follows: than had been predicted for the very It soon became apparent that these ob- transferred: fi ve to Johannesburg and fi ve small American satellites, and could usu- serva� ons were indeed urgently needed to Pretoria. United States 45 ally be spo� ed with the naked eye. The in some places. As from 13 December South Africa 33 procedure became, therefore, to obtain a 1957, the Union Observatory started to The Johannesburg instruments were re- Japan 5 large number of � mings of satellite posi- receive copies of cabled predic� ons with ceived on 1 March. The fi rst successful Australia 2 � ons in rela� on to whatever bright stars the code name “Harvest Moon” (later observa� on was obtained by HC Lagerwey could be iden� fi ed. These posi� ons were changed to “Space Track”) which had on 3 March, even before the instruments Amalgama� on of Johannesburg and Pre- then plo� ed, and a� er possible discrepan- been prepared by the Air Force Cam- were suitably mounted. At Bloemfontein toria teams cies had been removed, an accurate mean bridge Research Center, and which were the fi rst observa� on was made on 20 The proximity of the Johannesburg and posi� on obtained. Alterna� vely, the sat- being forwarded through the American March. Pretoria teams, both with a rather small ellite was photographed, with a 9x12cm Embassy in Pretoria. These proved to be number of instruments, and the la� er camera on Royal-X Pan sheet fi lm, using the fi rst predic� ons from elsewhere which The fi ve Pretoria instruments were almost en� rely dependent on the former a rudimentary hand-operated shu� er to agreed well with local observa� ons. From erected at a new observing site at the CSIR, for predic� ons, made it desirable that the obtain � ming marks on the trail. this � me onwards local observa� ons were which was likely to be more prac� cal, and two teams should amalgamate – at any regularly telephoned to the American Em- where the fi rst observa� on was made by rate for administra� ve purposes. On 23 Reports of Sputnik Observa� ons bassy for onward transmission. N van der Vlist on 22 March. From this February a combined mee� ng was held to When the ini� al excitement had begun to � me onward observa� ons of 1958 were give eff ect to this. die down, a new ques� on arose. It was all The Observatory was told that the visual made on a fairly regular basis un� l the end very well to observe Russian satellites, but observa� ons and predic� on data, as very of the year. Dr CN Williams was to be the Team Leader, what was to be done with observa� ons? kindly provided by Dr Finsen, had been with Mr RF Smith Deputy Team Leader in Were they really required by anyone? forwarded by telephone, cable and airmail Dr Finsen’s predic� ons proved to be Pretoria, and Mr JH Botham Deputy Team The Moonwatch project was started in to the associates. These communica� on invaluable for another purpose. Very Leader in Johannesburg. As the Assistant the fi rst place to observe American satel- arrangements having been developed great diffi culty was being experienced Coordinator, Mr J Churms, had resigned lites, and to observe them mainly at the in advance of the regular IGY repor� ng at the new photographic tracking sta� on from the Union Observatory at the end very beginning and near the end of their system envisioned by repor� ng satellites at Olifantsfontein, where very precise of 1957 and Mr J Hers was appointed in life. Observa� ons made in Johannesburg to be launched in the associates. The orienta� on of the Baker-Nunn Telescope his place. and Pretoria of Russian satellites were observa� ons furnished by the Union ob- mnassa vol 72 nos 5 & 6 112 109 june 2013 moonwatch: 1957 - 1958 satellite tracking servatory had proved to be were simply not capable extremely valuable: many of making such a faint of them were made at � mes object visible. It was, in when no sigh� ngs from oth- Dr Finsen’s words, like er parts of the world could be looking for a needle in obtained. It was felt it would the wrong haystack. be desirable if the South African Moonwatch observa- Pension of Opera� ons � ons from other sources (viz. in Johannesburg Pretoria, Bloemfontein and Immediately a� er Cape Town) could also be another unsuccessful forwarded. observing session in the very early hours of 9 Feb- The Cape Town Moonwatch team with Apogee telescopes. This interest proved to be a ruary, when it became (Image: Cape Times) The Explorer 1 Team, from L to R: William H Pickering, director of very great source of encour- the Jet Propulsion Laboratory, which designed and built Explorer, clear that the satellite agement to the amateur astronomers, Apogee Telescopes James A van Allen, University of Iowa physicist who directed the must have passed unob- and removed the last shreds of doubt Towards the end of 1957 Dr Evans was ap- design and crea� on of Explorer’s instruments and Wernher von served through the fi eld which there might have been as to the proached by Moonwatch Headquarters, Braun, head of the U.S. Army Ballis� c Missile Agency team that of several telescopes, a designed and built the Jupiter-C rocket. value of the observa� ons. asking whether he could use a number mee� ng was held of the of the so-called “Apogee Telescopes” (the 1958 Alpha – Explorer 1 Johannesburg Moonwatch Commi� ee, “Cosmos” Predic� ons high power small fi eld instruments origi- When the fi rst American satellite was which passed the following resolu� on: Very shortly a� erwards, on 10 January nally men� oned by Karl Henize) at each of launched on 1 February 1958, very de- “The Johannesburg Moonwatch Team has 1958, a communica� on was received the four South African sta� ons. The origi- termined eff orts were made to observe it, decided temporarily to suspend opera- from the IGY coordinator, Vice-Admiral A nal proposal was for 20 instruments for but these were wholly unsuccessful un� l � ons on the American satellite pending re- Day, conveying an off er from the IGY Com- each sta� on, but this was later changed 8 February when 1958 Alpha was seen ceipt of their Apogee telescopes.” mi� ee in the USSR, that ephemerides by the U.S. Naval Research Labora- by the Cape Town team using the newly should be transmi� ed direct to the tory, which had organized the project, to installed Apogee Telescopes. It was decided, however, to con� nue with various Moonwatch centres. This was a larger number of instruments for Cape a� empts to observe the satellite with gratefully accepted and “Cosmos” cables Town and Bloemfontein only, since it was Meanwhile in Johannesburg, Dr Finsen conven� onal narrow fi eld astronomical started to arrive in due course. For vari- felt that Johannesburg and Pretoria were had been making daily analyses and telescopes, as a purely observatory ac� v- ous reasons it was felt to be undesirable too far north to observe the American preparing predic� ons based on local Mini- ity, with the help of some of the more that individual teams should commu- “Vanguard” satellites for which the instru- track observa� ons and the rather infre- enthusias� c voluntary assistants, Dr Finsen nicate their observa� ons direct to the ments were intended. At Cape Town the quent orbit data received from overseas. con� nued his daily computa� on of predic- Soviet World Data Centre, and as funds instruments were installed at the Royal At the Observatory the regular Moon- � ons, using the Cape observa� ons to cor- were in any case not available at the Un- Observatory during January 1958, and a watch telescopes were supplemented by rect the orbital elements. His work was ion Observatory, the observa� ons were large number of observers were trained conven� onal astronomical telescopes, up rewarded in February when MD Overbeek communicated by telephone to Mr Hide’s to use them, but at Bloemfontein some to 12 inches (30 cm) in aperture, but the observed the satellite from his home using offi ce at the CSIR from where they were diffi culty was experienced in fi nding Cape Town observa� ons made it clear a 12-inch (30 cm) refl ector. The mean of cabled to Moscow. enough observers. that the regular Moonwatch Telescopes three observa� ons made on 20 February mnassa vol 72 nos 5 & 6 110 111 june 2013