A robotic telescope has been installed at the University of the Free State’s (UFS’s) Boyden Observatory, situated 26 km east of the provincial capital of Bloemfontein. The telescope, designated BOOTES 6, is part of an international network, created by an international collaboration which includes the Astrophysics Research Group of the UFS Department of Physics.
Boötes is the name of a constellation in the northern hemisphere (from the ancient Greek word meaning herdsman) but in the context of the telescope it is an acronym for ‘Burst Observer and Optical Transient Exploring System’. It, and the other telescopes in the network, are intended to observe transient high energy sources in the universe, including X-ray transients and gamma ray bursts (GRBs).
GRBs are thought to be created during the formation of black holes. Transient X-ray sources seem to be binary star systems, in which a star and either an incredibly dense neutron star or a black hole orbit around each other, with the neutron star or black hole pulling matter from the star on to or into itself. Variations in this process trigger the X-ray bursts.
The Astrophysics Research Group has a particular focus on high energy astronomy, and this research falls very much within its area of interest. It is important to note that the GRBs and transient X-ray bursts are, and can only be, detected and located by satellites in space. This information is swiftly passed on to the BOOTES research collaboration, and the telescopes, which are equipped with special cameras, are swiftly focused on to the source of the transient event, and then image it. All the telescopes are controlled from a single centre, in Spain.
“Since BOOTES has an enormously fast slew rate, it can start observations of erupting sources within a few seconds, which allows the Astrophysics Research Group to get data very quickly,” pointed out UFS Astrophysics Programme head and Physics Professor Pieter Meintjes. “This will certainly give us an edge over other international astronomy groups that are involved in the same type of research.”
The BOOTES collaboration is headed by the Institute of Astrophysics of Andalusia, in Spain. BOOTES 6 is, obviously, the sixth telescope in the global network. The previous five are located in Spain (BOOTES 1 and BOOTES 2), New Zealand (BOOTES 3), China (BOOTES 4) and Mexico (BOOTES 5). BOOTES 7 will be in Chile.
“By observing the optical afterglow of the [GRB], we can establish its point of origin in space,” he explained. “Furthermore, the shape of the optical afterglow light curve gives insight into the type of mechanism behind the [GRB], i.e., whether the burst is produced by a collision between two neutron stars or by the explosion of a hypernova [very energetic supernova] event.”
The project to build BOOTES 6 was launched more than two years ago, and the foundation and pier were constructed through a local tendering process. Part of the dome, to cover the telescope, arrived from Spain in January 2020. And then Covid-19 forced a pause on the project. The telescope and associated hardware, plus the Spanish specialists to assemble the system, were only able to come to South Africa last November, but the assembly team had to return to Spain before they could complete their work. They were only able to return in April. With the help of UFS personnel, the assembly and commissioning of BOOTES 6 was completed last month.