We are a group of enthusiasts who come from all walks of life and share a common interest in astronomy, an interest that may be deep and intense or slight and casual. We welcome and cater for all. Whatever aspect of astronomy turns you on, be it that you are purely interested in appreciating the beauty of the cosmos or wish to contribute to the advancement of science. Whether you enjoy tinkering with gadgets, want to talk about cosmology, or whatever else - we welcome you. Some of us own telescopes, some binoculars and some only a pair of sharp eyes with which to view the heavens.

As with several similar centres scattered in and around South Africa, the Johannesburg Centre is independent of, but affiliated to, the Astronomical Society of Southern Africa, the "parent body" generally referred to as ASSA.

Membership of the Centre confers several benefits. Not least of these is the opportunity to have contact with friendly, knowledgeable individuals who share your interests in astronomy. We freely impart our knowledge, ideas, enthusiasm, advice and experience. We encourage you to do likewise. 

As a member, you would have access to our facilities, including a library dedicated to astronomy and related disciplines. Successful completion a simple “driver’s course” will allow you the use of our instruments.

Apart from this, you get to participate in our other events and activities. Our ties to the Planetarium are also advantageous. Have you just purchased a telescope? We can help you to learn to set it up and use it. Are you thinking of purchasing one? We can help you make the right choice. Want to know what’s up there? Need to discuss your theories? We are here!

Activities

In addition to the activities already mentioned above, our members - according to their individual needs and interests - are involved in a variety of activities including the following…  

Telescope Making

Classes are conducted on an ongoing basis. With the application of some effort and a really modest outlay in cash, you too can build a fully functional telescope that will keep you happily observing for years to come.

A large number of instruments have been completed under our guidance over the last several years. These range from the basic and plain to the sophisticated, beautiful and even computer-controlled: in this case, not even the sky is the limit.

By building it yourself, you can not only save substantial sums of money, but also tailor-make an instrument to your own specific needs.

The satisfaction of fashioning an optical surface to an accuracy of a fraction of the wavelength of light with your bare hands is matched only by the pride of accomplishment when you stand back to survey your personal creation, and the enjoyment of observing with something you have built yourself. The first glimpse of the heavens through your own home-built telescope is truly an experience without parallel.

Even if you are not interested in building a telescope, visiting us may be worthwhile - you can learn how a typical astronomical telescope works and be better prepared for making purchasing decisions. 

Group Activities and Excursions

These range from star parties (informal gatherings for deep-sky viewing, often at dark sites, through visits to observatories, impact craters and other places of scientific interest, to meteorite hunting and even eclipse viewing expeditions.  We take advantage of circumstances such as visiting scientific luminaries, or astronomical events such as meteor showers and the appearance of comets to hold extra-ordinary meetings, observing sessions and gatherings. Courses in constellation recognition, basic astronomy, use of instruments and so on are offered whenever there is sufficient demand. There are also purely social activities, exemplified by the end-of-year “solstice party”. Once a year, we host the ScopeX Telescope and Astronomy exposition. Browse our site for more information.

Why not involve yourself in contributing to our newsletter Canopus? Researching areas of interest to you and putting them forth for others to enjoy is a fulfilling and educational experience.

Astronomy is anything from a passive hobby to a devout passion that covers a very wide range of fields of interest that can keep anyone happily engaged for an entire lifetime – but, it depends on an individual's bias – what interests you in particular.

Our centre has members with diverse interests – groupings occur that pursue specific interests on their own bat from time to time – the monthly meetings help to socialise the groups – the amateur telescope making group is quite strong – there are other groups that arrange/enjoy outings from time-to-time – and there are near-professional members that do serious observing and contribute to the development of science.

How to get started?

• read widely for you own enjoyment and establish a deep connection with the universe;
  
• get a pair of binoculars and observe the objects in the sky with the help of a guiding book (e.g.: ASSA Sky Guide) or download a free package from the internet such as 'Cartes Du Ciel' or 'Stellarium' that will help identify the objects that are visible from a given location;
  
• buy a telescope, learn how to use it, observe the objects in the sky, take photos of objects such as the Moon, planets or of deep-sky objects and then do image processing on the images to bring out detail, do formal observations and submit these to international organizations for further processing or ratification;
  
• build a telescope;
  
• etc.

You have probably thought that astronomy is usually done under very dark skies where people try to preserve their dark–adaptation. Some branches of observing and imaging do not need very dark skies or much dark adaptation at all. The most obvious are lunar and planetary observing. Many observers call this "shallow space" which can become a life's entertainment.

Our advice is to play to your strengths and interests in order to maximise your enjoyment, but also continue doing the groundwork you have started; a good foundation is important. A sound binocular observing mode will stand you in good stead in the future – we urge you to continue pursuing that and to achieve a relatively high level of skill before moving on to more expensive instrumentation.
 
Modern instruments indeed have a lot of embedded computing power, for go-to operation, to work in alt-az instead of equatorial mode, for imaging and so on. But you do not need a high level of expenditure to start with. Join some of our gatherings and find out why people made the instrumentation choices they did, rather than rushing off to spend money on the first thing a salesman punts. You can build or buy a modest scope, and maybe implement a tracking system that will enable imaging. Even a humble webcam can give great results. In fact, for planetary imaging, it is now possible to get better images with a webcam and a modest scope than the best professional images of just a few decades ago.

More advanced techniques involve high speed imaging of satellites or long duration images of distant galaxies. Some ‘amateurs’ have photographed the space shuttle in flight and could resolve the windows easily, others routinely look back in time for hundreds of millions of years. Of course, the more advanced your programme, the more expertise you have to develop yourself – that's part of the learning process.

If you equip a telescope or binoculars with the right filters, it is even possible to observe the vagaries and nuances of the Sun. Many of the tutors at the telescope making class will be more than happy to show you how to make a set of solar filters but please don't observe the sun without them – you could loose your sight permanently!

If your main interest is deep-sky, I suppose you are like most of us in that we have the most perverse fascination with the very things to which we are denied access! Indeed, in the city especially, light pollution is a curse, hiding most deep-sky objects. However, through digital photography it is possible to "subtract out" the light pollution and extract stunning images of deep-sky objects that would be impossible to observe visually under the same conditions. Of course, this requires a serious investment in equipment, and an even larger investment in personal time, effort and dedication. Not for the faint hearted, but achievable by those who have the drive.
 
If you enjoy tinkering with electronic toys and software, you would probably enjoy the challenges of imaging. You could avoid a lot of the start-up costs by teaming up with someone who is already well down that road. Perhaps you could find someone who has made the investment in equipment, but does not really have the IT skills required to bring out the best. Alternatively, you can access a lot of data on the Internet, and do real science by assisting an established programme in the data analysis process.

So – there's a lot to do. What you put in, is generally what you get out. However, astronomy is an endeavour that has the potential for you to marvel at our daily lives in a fashion very few people are privileged to experience and participate in.

The appearance of Halley’s comet in 1910, together with the appearance of another bright, even more spectacular comet in the same year, was the catalyst in getting a number of people in Johannesburg together to share their interest in astronomy. However, due to the interruptions of the first World War, it was only in 1918 that some members finally got around to forming an "astronomical society" as such. There had been a similar movement taking place in Cape Town, and in 1922 the two societies got together and formed the Astronomical Society of Southern Africa. This society and its member centres had its ups and downs, and it was only in 1948, after the second World War, that an active and organized organization emerged.

In the 1950’s the Johannesburg centre of the society enjoyed facilities at the old Union observatory in Johannesburg and assisted the professional astronomers there in conducting open public evenings to inform visitors of the happenings in the night sky. Membership of the society has always been open to all, whatever the level of interest and expertise in astronomy. There have been a number of members who have excelled in the field of amateur astronomy; Chris Papadopoulos, who had a keen interest in photography, photographed the entire sky using special filters so as capture the true visual magnitudes of the stars in an atlas that was used by astronomers, amateur and professional, the world over. Then there was Jack Bennett, a devoted comet hunter, who discovered two comets and was the first amateur astronomer in the world to visually discover a supernova. Danie Overbeek, who died in 2001, was the most prolific variable star observer in the world, having contributed more than 287,000 observations in his lifetime.

When the space age began in 1957 with the launch of the Russian Sputnik satellite, a group of members of the society worked with the Union observatory to set up a "moonwatch" team to observe and time the passage of satellites as they passed overhead. This continued for many years.

The society has built two small observatories on the premises of the Johannesburg Observatory, both for the use of its members and, more importantly, to conduct star viewing evenings for the general public.These public viewing events continue whenever there is sufficient demand.

In 1986, when Halley’s comet made its most recent appearance, the public were entertained on 20 consecutive nights to talks and telescopic views of the comet. On some nights the group was more than 100 strong. In addition, various members gave talks to school groups, church groups, boy scouts and girl guides, and to various public gatherings.

When comet Shoemaker-Levy 9 crashed into Jupiter in July 1994 the society again opened its doors to the public, who enjoyed seeing the Earth-sized scars on Jupiter left by the pieces of the comet. The society holds a meeting once a month, which normally takes the form of a lecture on some astronomical or related matter. However they also hold "star parties" and observing evenings, where members are invited to take along their telescopes and share their expertise. Visits to interesting sites are also arranged at suitable times.

A number of members have built their own telescopes. Classes started in about 1960 and were held sporadically when demand was sufficient. However the society has now conducted a prolific telescope making class continuously since 1993, where the craft of making telescopes is passed on to interested parties. Many fine instruments have been built in these sessions and their owners have enjoyed many pleasurable hours using superb instruments that they themselves have built. Instruments which have in turn inspired a whole new generation of telescope makers and amature astronomers alike.

The keener, more serious observers have been encouraged in the observation of variable stars, lunar occultations of stars and planets, occultations of stars by minor planets (asteroids), and of the monitoring of sunspots. Some members have also undertaken the observation of comets and meteor showers.

Today the Johannesburg centre is driven by a dynamic committee of enthusiasts who try their best to cater for the interests of all of its members.

Brian Fraser

One of the earliest references to the possible erection of a large telescope in Johannesburg is contained in a letter written on 1903 August 12 by Sir David Gill:

“Mr Innes (recently my secretary) has been appointed in charge of the Observatory there. At present his work is officially that of a meteorologist, but I have great hopes that, having regard to his proficiency as a double star observer, his enthusiasm and his power of exciting scientific sympathy, and the number of wealthy and large minded residents there, he will ere long be provided with a first class equatorial fitted for research on double stars.”

As Innes was now fully engaged in organizing the new Meteorological Department, as year passed without anything further happening, but on 1905 April 17 he again mentioned the subject to Gill:

“Telescope for Johannesburg: I hope you will not think me a worry re this. Kapteyn evidently thinks I could carry out some of his programme if the telescope was available, and I am willing to do my utmost, provided I have the telescope to do it with. I recently asked Grubb for his price for a telescope, and he quoted:
O.G. 24 inch: £ 2090
Equatorial: £ 2200
Floor: £ 1200
Dome 38 feet: £ 1400
TOTAL: £ 6800
So that the complete thing should cost about £10 000.

It is just possible that we may find one donor for the whole £10 000…”

[A subsequent exchange of correspondence followed.]

Unfortunately, in spite of all high hopes and declarations of support, no money was forthcoming from local sources. On 1906 August 17 Innes wrote to Gill:
“As to the big telescope for the Transvaal, I got Mr. Reyersbach (one of the partners at Ecksteins) interested in this, and he said that when he went home he would ask Mr. Beit for the money and felt pretty sure that Mr. Beit would give it. Mr. Beit died while Mr. Reyersbach was on his way home. This is a bit discouraging, and I have lost heart for the moment. Perhaps Mr. Reyersbach will ask Mr. Wehner…”

Plans for the large telescope where temporarily shelved, but they were suddenly given new life in 1909. One important reason for this seems to have been that at this time, shortly before the union of the four colonies, Transvaal was in a far better financial position than the others, and was aiming to keep some of this money within the province. This led to the almost immediate authorization by the Minister of Lands, the Hon. J.B. Rissik, early in 1909 of the purchase of a 26-inch refracting telescope.

It is related that Innes was asked to state in case at a meeting where both Smuts and Rissik were present. Smuts wanted to know whether such a big telescope was really necessary, to which Innes replied: “Well, no sir, but it will be such fun.” He was then asked what size telescope he needed, and thinking that it would be best to aim rather high, asked for a 26-inch telescope. Much to his surprise this was immediately agreed to, and Innes was left wondering ever after why he had not opted for a thirty or even a thirty-six-inch telescope.

A quotation for a 26-inch refractor was obtained from Sir Howard Grubb, which was accepted, and an order was placed on 1909 July 15. Sir David Gill was appointed scientific advisor for the project.

An endevour was made to fix a time limit for the completion of the whole telescope, but Sir Howard Grubb pointed out that this would be subject to the delivery by the manufacturers of suitable discs of optical glass, and that he could accept no responsibility for any delays due to their non-success in producing suitable glass. He promised that the object glass would be ready about 14 months after receipt of suitable discs.

[Glass manufacturers] Chance Bros. reported rather favorably, and they kept on doing so at intervals until all operations ceased at the outbreak of the War in August 1914. Sir David Gill died shortly afterwards, in December 1914.

When work was resumed after the end of the War, much was still to be done. On 1920 December 11 Grubb reported, “We estimate that quite 80% of the mechanical portion is completed”. The old orders for glass discs had lapsed, and as late as June 1922 no discs had been ordered by Grubb from any firm. Grubb pointed out that prices had risen sharply, and that he would be reluctantly obliged to ask for an increase of from £1 000 to £1 500 (which later became £2 500 to £3 500) over the original contract. Much argument ensued in an attempt to come to some agreement. In the end glass discs were ordered from Corning in the U.S.A., and construction of the telescope could proceed.

However, at the very end the whole project nearly ended in disaster. When the telescope was practically completed and ready for shipment Grubb (who had by now moved from Dublin to St. Albans) went insolvent. Fortunately the South African authorities in London heard of this in good time, and they took immediate steps to take receipt of the telescope and have it removed from Grubb’s premises before anything could happen to it.

A brief record of the sequence of events after the order for the telescope was placed in 1909 is provided by the Annual Reports of the Observatory:

1911: The tower, roof and moving floor are nearly ready for the 26-inch refractor and the mechanical parts of the telescope are well advanced.

1912: The building for the 26-inch refractor is practically ready to receive the telescope, but the glass discs for the lenses have not yet been cast.

1913: The discs for the 26-inch refractor have not yet been delivered to Sir Howard Grubb, but Messrs Chance Bros. hope to have them ready immediately, so that there is some prospect that the telescope may be in commission in 1914.

1914: The discs for the 26-inch refractor are not yet delivered to Sir Howard Grubb, so that the hope expressed in the last report that the instrument might be erected in 1914 has not been realised.

1915 – 1921: No references.

1922: Towards the end of 1922 the Union Astronomer went to England to superintend the completion of the mechanical portion of the 26-inch refractor under construction by Sir Howard Grubb and sons. It is understood that the objective will be completed early in 1924.

1923: The mechanical parts of the 26-inch refractor arrived at the Observatory in October, and the work of erection was at once commenced by the Public Works Department. A crown glass disc has been approved and is now being figured by Messrs Grubb, but at the moment of writing an approved flint disc has not been procured.

1924: The mechanical parts of the telescope were mounted early in the year, with the assistance of the Public Works Department. At the moment of writing the remaining portions of the telescope including the objective will very shortly be in commission. The condition of the object-glass has been the occasion of much anxiety, and the question of the final acceptance of the lens from the makers depends on tests which will be made here.

1925: The object-glass arrived here in January and by April the observations were begun. It cannot yet be said that the object glass is finally adjusted to its best working position, but during the last six months it has been in use every clear night, mainly, if not entirely, for double star observations. This work is summarized as follows:
   887 measures of double stars
   303 new double stars discovered
The great telescope is convenient to handle – it can be manipulated by one person, the observer… The most noticeable feature, to the observers here who are previously accustomed to much smaller apertures, is the power of the telescope in bringing out the colours of the stars. It would be ungracious not to mention our indebtedness to Sir Howard Grubb and his skilful staff.

Jan Hers