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31 January 2023 | Story Leonie Bolleurs | Photo Leonie Bolleurs
UFS unveiled new spectrograph
Assisting Prof Richard Gray with the installation of the spectrograph and the polarimeter were the Electronics and Instrumentation departments at both the UFS and the ASU. Left from the spectrograph, are from the left, front: Innes Basson, Head of the Department of Electronics and Instrumentation, Prof Pieter Meintjes, Senior Professor in the Department of Physics, Mark Jackson, Department of Electronics and Instrumentation, Hélène Szegedi, Lecturer in the Department of Physics, and Prof Richard Gray. At the right, from the spectrograph, front, are Natali Matchelt, master’s student, Izak van der Westhuizen, Lecturer in the Department of Physics; Barend Crous, Department of Electronics and Instrumentation; middle: Wian Smit, master’s student, Joleen Barnard, master’s student; back: Kobus Krüger, Department of Electronics and Instrumentation, Henri Roodt, Department of Electronics and Instrumentation; and Dr Hendrik van Heerden, Department of Physics.

The University of the Free State (UFS) is gearing up to be a leading academic institution in astronomical research. The institution successfully mounted a spectrograph with a polarimeter to the Boyden Observatory 1,5-m telescope that will provide scientists with visual access to both the Northern and Southern Hemispheres. 

The instrument, which can be accessed from Boyden, an astronomical research observatory and science education centre a few kilometres outside Bloemfontein, will allow researchers such as the Astrophysics Group at the UFS to do simultaneous polarimetry and spectroscopy of astronomical sources. This is vital for the research they are working on.

Mounting the spectrograph to the telescope and installing the polarimeter completed the upgrade of the 1,5-m telescope and is a leap forward for the astrophysics group at the UFS. The upgraded telescope with the spectropolarimeter, with a valued cost of R1.5 million, will also provide unique opportunities for collaborative research between the Astrophysics Groups at the UFS and researchers from the Appalachian State University (ASU). This adds greatly to the astrophysics research capacity at the university.
 
Prof Richard Gray, who 2019 started with the development of the astronomical spectrograph for the UFS Department of Physics, is a world-renowned expert in stellar spectroscopy, from the Department of Physics and Astronomy at ASU in North Carolina in the US. He was mainly responsible for the development and building of the instrument. 

Prof Pieter Meintjes, Senior Professor from the UFS Department of Physics, describes the moment that installation was completed as a feeling of enormous relief. “It took many hours of hard work, planning and testing to marry the 90-year 1,5-m telescope with the new sophisticated instrument,” he says. 

Adding value to graduate programme

Besides the development and installation of the spectrograph, Prof Gray also designed and built a polarimeter which can be integrated with the spectrograph. When placed inside the spectrograph, this piece of equipment transforms the spectrograph into a spectropolarimeter, giving it additional functionality. “This allows us, for example, to detect and analyse polarised light. It enables us to study the effect of magnetic fields in astronomical sources which introduce various polarisation signatures that can be detected with the polarimeter,” explains Prof Gray.

“I am fascinated by the polarimetric capabilities that we never had before. It is a great step forward,” remarks Prof Meintjes. 

“The Department of Electronics and Instrumentation at the UFS played an enormous role in the building of several components of the instrument that Prof Gray designed, as well as getting the 1.5-m telescope research ready so that the completed instrument could be mounted to the telescope”, says Prof Meintjes

He envisages that the research instrument will be ready for research purposes by March this year. Up till then researchers, graduates, and third-year students will have the opportunity to spend time on the spectrograph to familiarise themselves with it.

polarimeter
Prof Richard Gray posing with the polarimeter. With him is Prof Pieter Meintjes. (Photo: Leonie Bolleurs)


“Once installation is finalised, the UFS will be the only academic institution in South Africa with access to a 1.5-m telescope paired with a spectrograph. This gives us an edge in terms of our astrophysics programme and the training we provide our students. It also adds so much value to our graduate programme,” he says.

New instrument provides much flexibility

The spectrograph offers Prof Meintjes many possibilities for his research, and he is eager to put the instrument to use. To study binary systems as well as the jets of Active Galactic Nuclei (AGN), you need a spectrograph, preferably with polarimetric capabilities. It can also be applied to finding elements at the surface levels of stars so that their chemical composition can be determined.

“In the past, we needed to send our researchers to Sutherland and they were never guaranteed clear skies. Having this facility gives us so much flexibility,” he says.

 

Tsebo Matsoso and Siphephelo Ndlovu

Prof Brian van Soelen from the Department of Physics will be a key user of the spectrograph for his research. He is also playing an important role in terms of postgraduate training and research where the spectrograph is applied. 

Photo: Mart-Mari Duvenhage

  

 


The polarimeter converts the spectrograph to a spectropolarimeter. This instrument, which is mounted on a telescope (in the case of the UFS, it is mounted on the Boyden 1,5-m telescope) enables the user to detect whether radiation from  astronomical objects are polarised and to analyse the level of polarisation of the  light. Scientists can then, for instance, study the effect of magnetic fields in astronomical sources, which introduce various polarisation signatures (typically with a characteristic  level of polarisation).

News Archive

Childhood obesity should be curbed early
2017-03-15

Description: Child obesity Tags: Child obesity

Serious intervention by parents is required to deal
with childhood obesity. Prof Louise van den Berg and
a group of final-year PhD students worked on a study
about the prevalence of obesity in six-year-olds in
South Africa.
Photo: Supplied

If your child is overweight when they start school at the age of six, unless you do something about it at that point, the indications are they are going to be overweight teenagers and obese adults. This is according to University of the Free State’s Prof Louise van den Berg.

Evidence has shown that overweight children and teenagers have a greater risk of developing lifestyle diseases such as type 2 diabetes, hypertension and cardiovascular disease later in life, and dying prematurely.

Obesity is a global pandemic rapidly spreading among adults and children, in developed and developing countries alike.

Dr Van den Berg worked with Keagan Di Ascenzo, Maryke Ferreira, Monja-Marie Kok, Anneke Lauwrens, all PhD students with the Department of Nutrition and Dietetics, to conduct the study. Their research found that children who are overweight by the time they turn six should be screened for weight problems.

Why six-year-olds?
Children who are overweight between the ages of two and five are five times more likely to be overweight when they are 12. There are two periods in a normal life cycle when the body makes new fat cells. The first is in the uterus and the second is around the age of six. The second phase lasts from the age of six to puberty.

The study assessed the prevalence of obesity in six-year-olds as part of a campaign in South Africa to raise awareness of the problem among parents and educators.

A total of 99 children were chosen from seven schools in Mangaung, the capital city of Free State. The schools were chosen from quintile four and five schools, which when measured by their own resources and economic circumstances, are well resourced and serve largely middle-class and wealthy communities.

The children’s weight, height and waist circumference were measured and used to calculate a body mass index score and waist-to-height ratio. Both these figures are good predictors for future lifestyle disease risks such as type 2 diabetes, hypertension and cardiovascular disease. A person with a good waist-to-height ratio can wrap a piece of string equal to their height around their waist at least twice.

When the children had a higher body mass index, they also had an increased waist to height ratio. The study found one in four children from the schools surveyed were overweight when they started primary school.

Nipping the fat in the bud
Although there are many factors that play a role in preventing childhood obesity, parents’ perceptions of their children’s weight play an important role. A recent study found that more than 50% of parents underestimate the weight of their obese children. These parents remain unaware of the risks their children face and are not motivated to take any action.

At least half of the parents whose children are overweight struggle to recognise their children’s weight problems fearing that they will be labelled or stigmatised. By the time they turn six overweight children should be referred to dieticians and nutritionists who are qualified to guide their parents in getting them to eat well and be more physically active at pre-primary and primary school.

The high prevalence of weight problems among six-year-olds found in this study is an urgent call to healthcare professionals to step up and empower parents, educators and children with the necessary skills for healthy dietary practices and adequate physical activity.

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