Talks presented at the ASSA Symposium 2012 (videos)
The 9th National Symposium of the Astronomical Society of Southern Africa was held at SAAO, Cape Town, from 12 to 14 October 2012. The programme, with links to videos (on YouTube), follows:
Africa has been selected to host the mid-frequency dish array of the SKA, which will be one of the largest scientific infrastructures in the world. This presentation will give and overview of the activities of the SKA South Africa project, including preparation of the site proposal, the design and implementation of the MeerKAT, the Human Capital Development Programme, the African VLBI Network, and the C-BASS and PAPER experiments.
This talk is partly tutorial in nature and also focuses on some of the technical challenges that radio astronomy and the SKA brings. We look at parts of the signal chain for a radio telescope array, how this links to optical telescopes, and focus on imaging challenges in particular. Also addressed are some of the computing/data rate issues that accompany the new instruments.
Galaxy clusters are the largest known gravitationally-bound objects in the Universe and form the densest part of the large-scale structure of the universe. I will discuss their nature and formation, and how observations involving galaxy clusters have already, and will in the future, contribute to our understanding of dark energy.
Since the late 1990s, digital photography and advances in telescope technology and associated software have allowed amateurs to not only take visually pleasing images of space, but also contribute to science. This talk will give a generaloverview of what is now possible for amateurs to achieve. Based on the presenter's own experience, topics will include data capturing, image processing and typical hardware requirements.
Open clusters are an important species of galactic inhabitants. Their study sheds light on fundamental galactic properties and gives insights into stellar evolution. Before they can be studied, however, they need to be discovered. My talk will briefly outline this identification process, and describe the contributions made by amateur astronomers in compiling a more complete census of galactic open clusters.
An illustrated history of the telescopes at the Sutherland observation station of the SAAO.
I will present images of the night sky which I have taken with a modified DSLR on a tripod in urban regions in both the southern and the northern hemispheres. The images obtained so far include all 88 constellations, all 110 Messier objects and a number of NGC and IC objects down to about 10th magnitude. Each picture is a combination of a large number of short exposures, and I will show the procedures used for taking and processing the individual images and how the light pollution contribution is removed from the data. This project is an example of what can be achieved in astrophotography with minimum equipment from an urban site, and the techniques presented here are an effective tool to get people interested in the subject no matter where they are.
The purpose of the presentation will be to share my experiences and knowledge gained in the making of two 20-inch f/4.3 telescope mirrors. It will cover details of a versatile machine that was built for the grinding, polishing and figuring of the mirrors. It will further include details of the various full and sub-diameter tools that were made and used. An explanation will be presented on the optical testing methods used throughout the figuring process, including an improved application of the Foucault test and the corresponding digital data reduction techniques.
Astronomy online, discussed by Allen Versfeld.
In my 25 years of active involvement in the Pretoria Centre of ASSA, I have thoroughly enjoyed interfacing with scholars and the general public. This interaction has led me to an understanding of what the public wants to know and how to explain astronomy concepts to them. Capturing the attention of students with breathtaking views through the telescope and quoting huge numbers no doubt impresses, but leaving the students with a genuine understanding that they can take away with them and use as a base towards a further appreciation of astronomy and science requires particular techniques. I have used my experience to develop models which effectively replace 30 minutes of words and much confusing arm waving. This talk presents the lessons I have learned which form the basis of my approach to outreach. I took this same approach in a book that I have written. The book was released a few months ago.
Bloemfontein’s Two Observatories Project was launched in 2011 by the Physics Department at the UFS in close collaboration with ASSA Bloemfontein and the Free State Department of Economic Development, Tourism and Environmental Affairs (DETEA). The aim of the project is to preserve Bloemfontein’s two observatories, namely, the Boyden Observatory and the Lamont Hussey Observatory, and to develop these facilities for academic, public and educational use. The last 20 years have seen a rapid revival of astronomy in Bloemfontein. Boyden Observatory was upgraded in several different phases, and included the refurbishment of the Boyden 60-inch telescope. An active astrophysics research group was established at the UFS. At this time, a long-held dream to establish a planetarium in Bloemfontein is about to be fulfilled at the old observatory on Naval Hill. This talk will outline the involvement of ASSA in public and educational events including astronomy fairs and other outreach events, renovation and improvements of old telescopes, and finally, in historical research.
Astronaissance neatly conceptualizes the crossover between the African Renaissance, the revival of Astronomy in Africa, and the rise of Astronautics and cognate space sciences . Story-telling, painting, engraving, writing, and above all, viewing the heavens above, have always been amongst the strategies for communicating this excitement and wonder. Today the Internet, learned societies, media, and public outreach projects are crucial when, for the first time ever, a majority of Africa’s people now live under the light-polluted skies of our continent’s towns and cities. Space-related products and services are woven into the fabric of our daily life as never before. Policy-makers and allocators of resources need to see as essential to their strategy communicating to Africa’s citizens, voters, and taxpayers, the necessity of Astronomy, Astronautics, and the other space sciences.
Over 800 extrasolar planets (planets associated with stars other than the Sun) have been discovered by a variety of methods. In this talk I will give an outline of the detection methods, concentrating on those techniques employed by several different pro-grammes at Sutherland.
Twenty-three original pencil sketches of astronomers who have left their mark in astronomical history, hand-drawn by Kathryn van Schalkwyk. A brief remark about every figure including Barnard, Bennett, Herschel, Abell, Overbeek, Messier, Farell. My intention is to present the collection to the President of ASSA, Ian Glass, during the proceedings as a contribution to the Observatory Library.
In 1751-53 Nicolas-Louis de La Caille of the Royal Academy of Sciences in Paris was the first important scientist to visit the Cape. At the age of 39 he came to the Cape and built an observatory close to Rogge Bay, near the present-day Strand and Heerengracht streets. From this he surveyed the southern sky through a telescope: the first systematic survey made in either hemisphere. He named fourteen new constellations after the scientific instruments of the time, except for one, Mensa or Table Mountain. Other scientists in France had just found that the Earth is not round, but is flattened towards the North Pole. La Caille decided to measure its shape in the south by means of astronomical observations and a ground-based survey from Cape Town to the Piketberg. He was astonished to find that the planet seemed to be slightly pear-shaped. La Caille kept a most interesting journal of his stay at the Cape containing, besides scientific notes, many comments on the colonists, the natural surroundings and other matters. His precise writing avoided the sensationalism of earlier visitors.
The Cape Astronomical Association was formed 100 years ago, in October 1912. As far as we know, this was the first astronomical association in South Africa. The initiative resulted from public interest in astronomy after the re-appearance of Halley’s comet the previous year. From the beginning, the society was a close co-operation between amateur and professional astronomers. In fact, the founding meeting held by amateurs, was postponed in order to invite professional astronomers to join. SS Hough, Astronomer Royal at the Cape of Good Hope became the first Honorary President. Ten years later this association gave rise to the Astronomical Society of South Africa (ASSA). The talk will also discuss the ASSA archives housed in Cape Town.
The presentation provides an analysis of the current South African school curriculum in terms of astronomy content. When the curriculum was revised in the 1990s and early 2000s, astronomy was moved from the geography curriculum into the natural sciences. At the primary and junior secondary school level, basic astronomy content is relatively well covered in terms of the solar system and ‘space science’, with relatively little reference to current issues that occupy astronomers and cosmologists. Further there is a paucity of astronomy in the FET level of schooling (grades 10-12) so that there is no sequence of conceptual development of astronomical topics from upper primary school to matric level. The presentation considers the issues raised by Adams and Slater (2000), Sadler (2001) and Pasachoff (2001, 2002) in the USA, regarding the sort of astronomy that should be taught at school and early tertiary level. In view of the positioning of South Africa as an astronomy ‘hub’, the consequences of the current status of astronomy in the school curriculum are discussed, and recommendations for its development are made.
Both astronomy and physics often have to deal complex concepts and one way to address this problem is by using analogies. However, many of these frequently require a high level of prior knowledge, reducing, or even nullifying, the analogy's effectiveness. In addition it needs to be understood that any analogy serves a limited purpose: it cannot be extended beyond its intended objective. This will use some well-known, not so well-known and new analogies in astronomy and physics using usually understood prior knowledge.
19. Talking about astronomy in the Internet era, presented by Lia Labuschagne [no video available]
In a world where busy people complain about information overload, it is a challenge to communicate effectively about any topic - and that includes science in general and astronomy in particular. People's communication needs, habits and preferences are changing rapidly - and at the same time there is a constant flow of useful data and interesting information about astronomy from a myriad of sources. Lia will look at the context of communicating about science and touch on some of the ways in which we can ensure that our communication is interactive, integrative and imaginative. She will also touch on the potential of e.g. social media and mobile technologies to integrate with more traditional channels of communication and outreach.
MeerKAT is South Africa's SKA precursor telescope and will consist of 64 SKA-ready radio dishes. This array of telescopes is currently under construction near Carnavon in the Northern Cape and is expected to start full scientific operations in 2016. After a few words on the main science goals of the SKA, I will give an overview of the large legacy survey projects that have been defined for MeerKAT, and give more details on the ones that are UCT-led. This will include some of the observations that have been performed to-date with KAT-7, the MeerKAT technology demonstrator.
This talk will give a review of SALT, the issues we dealt with in getting it going, the first science results and the future possibilities.
We review the amazing progress that has been made in observational cosmology over the past 15 years, discuss the big open questions and look forward to the incredible changes that we can expect in the next 15 years.
Two observatories and their environment are presented and the observing instrumentation discussed. A brief introduction to variable stars and differential photometry are given. Five major observing programmes are described, observing results shown and merits discussed. The presentation will include many photographs and diagrams.
Space debris is becoming an ever-increasing threat to artificial earth satellites. This talk describes the amateur contribution to detecting such debris and outlines the various techniques used and results achieved.
Nicola will present an overview of the outreach programme at the South African Astronomical Observatory (SAAO). Her talk will outline the aims of the programme and briefly summarise the initiatives used by the SAAO to reach learners, educators and the general public. The scale of the programme will be examined and a few recent highlights mentioned along with exciting future opportunities.
Closing of the Symposium by Ian Glass.
nothing more to see. please move along.