BLAAI AF VIR AFRIKAANS

South Africa played a leading role in the development of astronomy in the Southern Hemisphere since earliest times, as result of the accessibility of Cape Town and the favourable observation conditions on the High veld, which made South Africa an ideal area for astronomers who wished to extend, continue and complete their observations made in the Northern Hemisphere in the Southern Hemisphere.

The earliest astronomical observations in South Africa were made by the earliest navigators to determine the lines of latitude and longitude. These were essential for correct shipping navigation. Obviously sporadic observations were made of spectacular astronomical phenomena such as comets. In his journal Jan van Riebeeck referred to a comet which appeared on 17 December 1652.

The first person with astronomical training who visited the Cape, was the Jesuit priest Father Guy Tachard in 1685. He had a temporary observatory at Cape Town on the site of the present Iziko Museum. He studied southern stars through a 3,8 meter long telescope and discovered many southern stars. 20 years after Tachard’s departure, the German Peter Kolbe arrived at the Cape to determine the distance to the moon by astronomical observations. His observatory was situated on the Buren bastion of the Castle of Good Hope.

The most successful astronomer was the French astronomer Abbé Nicolas Louis de la Caille who worked at the Cape from 1751 to 1753. In those two years he laid the foundations of astronomy in the southern hemisphere. He accurately identified 9766 stars and 42 nebulae and combined it with his European research. He then measured the meridian from Cape Town northwards to Klipfontein, Aurora, (see map) a distance of more than 140 kilometers to determine the shape of the earth in the Southern Hemisphere. The surrounding mountains caused a deviation in his observations. This deviation was corrected by Maclear 90 years later.

Constellations are chance arrangements of stars as seen from earth and have been defined differently by different cultures over millennia . The majority of constellations in the northern hemisphere have names from ancient Greek myths , but may have originated in Chaldean or Cretan society. Other constellation names were added in Europe in the late sixteenth century.

The first star atlas, published in 1603 by Johann Beyer had twelve additions to the forty eight ancient constellations listed by Ptolemy. 2000 years ago the Southern Cross was visible from Alexandria. Today it is not possible because of the precession of the earth’s axis. The twelve constellations new to the original list were invented by Dutch navigators Petrus Theodori of Emden and Freidrick Houtman, who sailed extensively in the southern seas. Their names for the constellations showed impressions that their travels had made on them: Apus (die Bee), Chameleon, Dorado (die Swordfish), Grus (the Crane), Hydrus (die Little Snake), Indus (the Indian), Musca Australis (Southern Fly), Pavo (the Peacock), Phoenix, Pisces Volans (Flying Fish), Triangulum Australe (Southern Triangle), Tucana (the Toucan). In 1676 het Halley compiled a catalogue of 341 southern stars. 70 years later Halley’s catalogue was still the only one in existence. The French Academy of Sciences sent the young Abbé Nicolas Louis de la Caille with suitable astronomical instruments on an expedition to the southern hemisphere in 1750. Le Caille arrived at Cape Town on 19 April 1751 and set up his instruments at Strand Street 7 where he resided for two years. Within a year he had measured the positions and estimated the brightness of nearly 10 000 stars. He found the existing southern constellations inadequate to give Greek alphabetic designations to all the bright stars, so he invented fourteen new constellations for this purpose. His catalogue had such authority that these constellations were all adopted and are used to this day.

He then determined the radius of earth.

In 1761, eight years after De la Caille’s departure, Mason and Dixon arrived at the Cape to observe the transit of Venus. Two astronomers A Mart and CM Stevens observed the transit of Venus on 6 December 1882 from a point behind the Douglas Hotel at Touws River (see map)where a historical monument was erected. These observations were done to determine the exact distance between the sun and the earth. The majority of northern constellations were named after figures in Greek mythology. De la Caille named the new constellations after objects from his own profession: Antlia Pneumatica (Air Pump), Apparatus Sculptoris (Sculptor’s tools), Caela Sculptoris (Sculptor’s chisel), Circinus (the compass), Equuleus Pictoris (Painter’s Easle), Fornax Chemica (Chemical Furnace), Horologium (Clock), Microscopium (Microscopde), Mons Mensa (Table Mountain) [the only constellation named after a landform], Telescopium (Telescope). Nowadays the Latin names are abbreviated, eg. Antla, Pictoris, Fornax.

Le Caille was so impressed by Table Mountain and its cloth, that he permanently united Mons Mensa and the Large Magellanic Cloud as Table Mountain and its cloud ! The only constellation without bright stars named after a landform. A unique name of a famous and beloved South African landmark !

The first official permanent observatory in RSA was established at Cape Town on 20 October 1820 as ordered by the Royal Observatory by Orders in Council. Official astronomy and observatory in South Africa is 200 years old this year.

This was initiated by the Board of Longitude in Britain which wanted to extend the astronomical research of the Royal Observatory at Greenwich, London, to the Southern Hemisphere. The first astronomer was Rev. Fearon Fallows who arrived at Cape Town in Augustus 1820. He established a temporary observatory in Cape Town in 1825. The present observatory building was built between February 1825 and June 1827 in Observatory Road, Observatory [see map]. Fallows then moved there. The instruments were installed there in 1828. Fallows and his successors Henderson, Maclear, Stone, Gill, Hough Jones and Jackson all greatly contributed to the advancement of astronomy and general science in South Africa.

The famous British astronomer sir John FW Herschel came to the Cape in January 1834 to make astronomical observations. He brought a reflecting telescope of six meters focal length which he set up in the suburb of Claremont where he stayed until March 1838. During his stay he charted the Argo nebula, placing 1203 stars in it; catalogued 1 163 objects in the Magellanic clouds; discovered 1202 pairs of double stars and observed Halley’s comet from 28 October 1835 to 5 May 1836. On his departure in 1838, he placed a small granite cylinder on the spot where the six meter telescope had stood and on the 5th February 1841, an obelisk of Craigleith stone was erected on top of this cylinder. The inscription reads: “Here stood from MDCCCXXXIV to MDCCCXXXVIII the reflecting telescope of sir John FW Herschel, Baronet, who during a residence of four years in this colony contributed largely by his benevolent exertions to the cause of education and humanity as by his eminent talents to the discovery of scientific truth.”

The site of the obelisk has recently been incorporated in the grounds of the Grove Primary School. It was proclaimed as historical monument in 1936.

STERREKUNDE IN RSA 1820 – 2020: 200 jaar

Suid-Afrika het sedert vroegste tye reeds ’n leidende rol in die ontwikkeling van sterekunde in die Suidelike Halfrond gespeel as gevolg van die bereikbaarheid van Kaapstad en die gunstige waarnemingsomstandighede op die Hoëveld, wat Suid-Afrika ’n natuurlike ideale gebied gemaak het vir sterrekundiges wat hul werk in die Noordelike Halfrond hier in die suidelike Halfrond wou voortsit, uitbrei en voltooi.

Die vroegste sterrekundige waarnemings in Suid-Afrika is deur die vroegste navigators gemaak om die lengte- en breedtelyne te bepaal. Daar was natuurlik sporadiese waarnemings van opvallende sterrekundige verskynsels soos komete. Jan van Riebeeck verwys in sy Joernaal na die verskyning van ’n komeet op 17 Desember 1652.

Die eerste persoon met sterrekundige opleiding wat die Kaap besoek het, was die Jesuïete priester Vader Guy Tachard in 1685. Hy het’n tydelike sterrewag in Kaapstad ingerig op die terrein van die huidige Iziko Museum. Hy het suidelike sterre deur ’n 3,8 meter lange teleskoop bestudeer en talle suidelike sterre ontdek. 20 jaar na Tachard se besoek, kom die Duitser Peter Kolbe in die Kaap aan om die afstand na die maan deur waarneming te bepaal. Sy sterrewag was op die Buren bastion van die Kasteel Goeie Hoop.

Die suksesvolste sterrekundige was die Franse sterrekundige Abbé Nicolas Louis de la Caille wat van 1751 tot 1753 aan die Kaap gewerk het. In dié twee jaar het hy die grondslag van sterrekunde van die Suidelike Halfrond gelê. Hy het 9766 sterre en 42 newels met noukeurigheid geïdentifiseer en gekombineer met sy Europese navorsing. Hy het die merdidiaan noordwaartsvan Kaapstad na Klipfontein, Aurora, (sien kaart) oor 140 kilometer bepaal en opgemeet om die vorm van die aarde in die Suidelike Halfrond te bepaal. Die omliggende berge het egter ’n afwyking in sy waarnemings veroorsaak. Hierdie afwyking is eers 90 jaar later deur Maclear reggestel.

Sterrebeelde is toevallige rangskikking van sterre soos waargeneem vanaf die aarde. Deur millennia het verskillende kulture dit verskillend beskryf. Die meerderheid, veral in die noordelike halfrond, dra name uit die Griekse mitologie, maar kon dalk reeds so vroeg as die Chaldeese of Kretense tydperke dateer. Ander name is gedurende die 16de eeu in Europa bygevoeg. Die oudste steratlas is in 1603 deur Johann Beyer gepubliseer en het 12 sterrebeelde bygevoeg by Ptolemeus se oorspronklike 48. Ptolemeus kon 2000 jaar gelede die Suiderkruis uit Alexandria waarneem. Vandag is dit onmoontlik weens die aardaswenteling. Die twaalf nuwe sterrebeelde is deur Nederlandse navigators Petrus Theodori van Emden en Freidrick Houtman wat oor die suidelike oseane geseil het, ontdek. Die name wat hul vir die sterrebeelde gegee het, weerspieël hul reiswaarnemings: Apus (die By), Chameleon, Dorado (die Swaardvis), Grus (die Kraanvoël), Hydrus (die Klein Slang), Indus (die Indiër), Musca Australis (Suidelike vlieg), Pavo (die Pou), Phoenix, Pisces Volans (Vlieënde Vis), Triangulum Australe (Suidelike Driehoek), Tucuma (die Toekan). In 1676 het Halley ’n katalogus van 341 suidelike sterre opgestel. 70 jaar later was Halley se katalogus steeds die enigste van suidelike sterre. Die Franse Akademie van Wetenskap het Abbé Nicolas Louis de la Caille met sterrekundige instrumente in 1750 op ‘n ekspedisie na die suidelike halfrond gestuur. Le Caille het Kaapstad op 19 April 1751 bereik en sy instrumente by Strandstraat 7 opgestel waar hy twee jaar gewoon het. Binne ’n jaar het hy die posisies en geskatte helderheid van sowat 10 000 sterre aangeteken. Hy het die aantal suidelike sterrebeelde te min gevind om Griekse alfabetiese benamings te gee. Daarom het hy 14 nuwe sterrebeelde geïdentifiseer. Sy katalogus was so gesaghebbend dat dit net so aanvaar is en tot vandag nog gebruik word.

Daarna het hy die straal van die aarde bepaal.

In 1761, agt jaar na De la Caille se vertrek, het Mason en Dixon die Kaap besoek om die deurgang van Venus waar te neem. Twee sterrekundiges, A Mart en CM Stevens het op 6 Desember 1882 ook die deurgang van Venus waarge-neem vanaf ’n punt agter die Douglas Hotel op Touwrivier (sien kaart) waar ’n historiese gedenksteen opgerig is. Hierdie waarnemings is gedoen om die presiese afstand tussen die son en die aarde te bepaal. Die meerderheid noordelike sterrebeelde is na figure uit die Griekse mitologie benoem. La Caille vernoem die nuwe beelde na voor-werpe uit sy professie: Antlia Pneumatica (Lugpomp), Apparatus Sculptoris (beeldhouer se gereedskap), Caela Sculptoris (Beeldhouer se beitel), Circinus (die passer), Equuleus Pictoris (Skilder se Esel), Fornax Chemica (Chemiese Oond), Horologium (Horlosie), Microscopium (Mikroskoop), Mons Mensa (Tafelberg) [die enigste sterrebeeld wat na ’n landvorm vernoem is], Telescopium (Teleskoop). Deesdsdae word die Latynse name verkort, bv. Antla, Pictoris, Fornax.

Só beïndruk was Le Caille met Tafelberg en sy kleed, dat hy Mons Mensa en die Groot Magellaanse Wolk permanent verenig het as Tafelberg met sy kleed ! Die enigste sterrebeeld sonder werklik helder sterre. ‘n Unieke benoeming van ‘n bekende en geliefde Suid-Afrikaanse landmerk !

Die eerste amptelike permanente sterrewag in RSA is op 20 Oktober 1820 te Kaapstad deur Orders in Council in opdrag van Royal Observatory gestig. Amptelike sterrekunde en sterrewag in Suid-afrika is dus vanjaar 200 jaar oud. Die inisiatief was afkomstig van die Board of Longitude in Brittanje wat die sterrekundige navorsing van die Royal Observatory te Greenwich, Londen, na die Suidelike Halfrond wou uitbrei. Die eerste sterrekundige was Rev. Fearon Fallows wat in Augustus 1820 in Kaapstad aangekom het. Hy het voorlopig tot 1825 ’n tydelike sterrewag in Kaapstad gehad en het daarna na die huidige terrein getrek. Die huidige gebou van die sterrewag in die suidelike voorstede is eers tussen Februarie 1825 tot Junie 1927 in Observatory Road, Observatory, opgerig. Die instrumente is eers in 1828 geïnstalleer. Fallows se opvolgers Henderson, Maclear, Stone, Gill, Hough, Jones en Jackson het almal grootliks bygedra tot bevordering van sterrekunde en algemene wetenskap in Suid-Afrika.

Sir John Herschel, die beroemde Britse sterrekundige het in Januarie 1834 na die Kaap gekom om sterrekundige waarnemings te doen. Hy het sy ses meter teleskoop in die voorstad Claremont opgestel. Hy het 1203 sterre in die Argo newel geïdentifiseer, 1163 voorwerpe in die Magellaanse wolke gekatalogiseer, bykans 2000 ander newels ontdek, 1202 pare dubbel sterre ontdek en Halley se komeet van 28 Oktober 1835 tot 5 Mei 1836 waargeneem.

By sy vertrek in 1838 het hy ’n klein granietsilinder op die plek geplaas waar sy teleskoop gestaan het. Op 15 Februarie 1841 is ’n obelisk van Craigleith klip bo-op die silinder gemonteer met die inskripsie: “Here stood from MDCCCXXXIV TO MDCCCXXXVIII the reflecting telescope of sir John FW Herschel, Baronet, who during a residence of four years in this colony contributed largely by his benevolent exertions to the cause of education and humanity as by his eminent talents to the discovery of scientific truth.”

Die perseel van die obelisk is onlangs ingeskakel by die terrein van die Grove Primary School. Dit is in 1936 as historiese monument geproklameer.

Bronnelys

• AA Touring Guide to Southern Africa
• Athiros, G & L: The best of The Cape Odyssey
• Athiros, G & N: The Cape Odyssey
• Boëseken. AJ: Die Nuusbode; Kruger, DW: SABW, Dl 3
• Map studio: Street Guide, Cape Town
• Oberholster, JJ: The Historical Monuments of South Africa
• Potgieter, DJ: SESA 1, 3. 7, 8, 10: Rosenthal, E: Encyclopedia of Southern Africa