On 12 June 2014 the well-known astronomer Tom Lloyd Evans died in Scotland. For most of his career he had worked in South Africa but for the last thirteen years of his life he lived in Scotland, not far from where he grew up.
This article continues the sequential numbering of reported fireball sightings from southern Africa, and covers fireballs observed during 2013. By definition, a fireball is any meteor event with brightness equal to or greater than visual magnitude (mv) -3. The following events were reported to the author and details are reproduced as given by the observer. All times were converted to UT unless stated, and all coordinates are for epoch J2000.0.
Nine bright southern double stars were measured and compared with observations made by Bob Argyle (from Cambridge University) using the 26" refractor in Johannesburg and the values listed in the Washington Double Star Catalog (WDS). The exercise was done to see whether a small telescope with a Meade Astrometric eyepiece could give results that are of sufficient accuracy to be of scientific value. The main reason for measuring double stars is to determine the total mass of a double-star system. Why? This information is of crucial importance to theorists working on stellar evolution. Indeed, our understanding has benefited greatly from thousands of measurements made by double-star observers since the time of Wilhelm Struve in the early 19th century.
This is the third article of what is planned to be several, covering the history of amateur satellite tracking in South Africa during the period 1957 to the present. It will concentrate almost exclusively on optical tracking rather than being a complete record of optical and radio tracking and will only handle observers who reported scientific data to the various tracking networks.
These form an important part of a research facility, often as a sort of prepublication discussion or a discussion of an individual's current research, and as such it is virtually impossible to "publish" this material. However by recording the topics discussed in the form below does indicate to those, who are unable to attend, what current trends are and who has visited to do research: it keeps everyone 'in the loop' so to speak.
Also included in this section are the colloquia/seminars at the SAAO, UWC and the Astrophysics, Cosmology and Gravity Centre at UCT, ACGC. Also included are the SAAO Astro-coffees which are 15-20min informal discussions on just about any topic including but not limited to: recent astro-ph papers, seminal/classic publications, education/outreach ideas and initiatives, preliminary results, student progress reports, conference/workshop feedback and skills-transfer.
When the constellation Libra pops its head up above the eastern horizon it also brings the importance of balance to the fore. Balance has relevance to many things, not only to us as people, but also, and especially, to astronomy. Is our inclination not frequently to seek out only the bright deep-sky objects whether with a telescope, binoculars or the naked eye, while so many of the fainter objects are pushed aside? And this is where, when a balance is maintained, we can be surprised by the results. Libra is located just north of the better known constellation Scorpius. The stars currently making up the constellation were first characterised by Eratosthenes as the pinchers or claws of the Scorpius shape.