ISSN 0024-8266 mnassa Monthly Notes of the Astronomical Society of Southern Africa Vol 72 Nos 5 & 6 June 2013 mmonthly notes nof the astronomicalas societys of southerna 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). Membership of any of these Centres automa� cally confers membership of the Society. editorial address MNASSA, PO Box 9, Observatory, 7935, South Africa e-mail: [email protected] Sky & Telescope: Members may subscribe to Sky & Telescope at a signifi cant discount (proof of Cen- tre membership required) . Please contact membership secretary for details. webpage: h� p://mnassa.saao.ac.za Internet contact details: e-mail: [email protected] homepage: h� p://assa.saao.ac.za MNASSA Download Page: www.mnassa.org.za subscriptions From January 2011 MNASSA is available free of charge on Council (2012–2013) the Internet. Paid subscrip� ons will no longer be available President Dr IS Glass [email protected] (see MNASSA, August 2010, p.113). Vice-president Prof MJH Hoff man Hoff [email protected] Membership Secretary Pat Booth [email protected] advertising rates Adver� sements may be placed in MNASSA at the following Hon. 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.