Enkele aspekte van Skrifbeskouing

View of Scripture: Some aspectsThis essay deals with the relation between God’s work and man’s actions in the world as the basic problem in connection with our view of the origin and form of theBible. The position assumed is that in the Old Testament there are at least two different ways of looking at the problem: In literature with a polemic tendency(especially in books from the time of the Babilonian exile) the omnipotence and predestination of God is stressed. In wisdom-related literature the more prominentview is that man was free to choose for himself although the outcome was always in the hand of God. It is argued that, due to the fact that they were in a polemic situation, the first option was dominant in the theological reflections of orthodoxy. The thrust of the essay is that, regarding different aspects of our view of Scripture, the possibilities of the second option must by exploited

Egge Simon Mulder, hoogleraar

Egge Simon Mulder, professor from 1956 to 1970E S Mulder succeeded Berend Gemser as professor in Old Testament Studies in the Faculty of Theology (Sec A) at the University of Pretoria. His approach was historicalcritical and at the same time he was totally committed to the ecclesiastical ministry. He can be characterised as an exponent of so-called Ethical Theology.Although he did not fully integrate his scientific work and his theologising within the scope of the church, he contributed to the present close ties between the Facultyand the Nederduitsch Hervormde Church, as well as to the ethos that there is no dichotomy between reason and faith

High-speed photometry of the eclipsing polar UZ Fornacis

We present 33 new mid-eclipse times spanning approximately eight years of the eclipsing polar UZ Fornacis. We have used our new observations to test the two-planet model previously proposed to explain the variations in its eclipse times measured over the past $\sim$35 years. We find that the proposed model does indeed follow the general trend of the new eclipse times, however, there are significant departures. In order to accommodate the new eclipse times, the two-planet model requires that one or both of the planets require highly eccentric orbits, that is, $e \geq$ 0.4. Such multiple planet orbits are considered to be unstable. Whilst our new observations are consistent with two cyclic variations as previously predicted, significant residuals remain. We conclude that either additional cyclic terms, possibly associated with more planets, or other mechanisms, such as the Applegate mechanism are contributing to the eclipse time variations. Further long-term monitoring is required.Comment: 11 pages, 5 figures, Accepted for publication in A&

IGR J19552+0044: A new asynchronous short period polar: "Filling the gap between intermediate and ordinary polars"

Based on XMM--Newton X-ray observations IGR J19552+0044 appears to be either a pre-polar or an asynchronous polar. We conducted follow-up optical observations to identify the sources and periods of variability precisely and to classify this X-ray source correctly. Extensive multicolor photometric and medium- to high-resolution spectroscopy observations were performed and period search codes were applied to sort out the complex variability of the object. We found firm evidence of discording spectroscopic (81.29+/-0.01m) and photometric (83.599+/-0.002m) periods that we ascribe to the white dwarf (WD)\ spin period and binary orbital period, respectively. This confirms that IGR J19552+0044 is an asynchronous polar. Wavelength-dependent variability and its continuously changing shape point at a cyclotron emission from a magnetic WD with a relatively low magnetic field below 20 MG. The difference between the WD spin period and the binary orbital period proves that IGR J19552+0044 is a polar with the largest known degree of asynchronism (0.97 or 3%).Comment: 9 pages, 10 figures, A&A accepte

The structure of Chariklo's rings from stellar occultations

Two narrow and dense rings (called C1R and C2R) were discovered around the Centaur object (10199) Chariklo during a stellar occultation observed on 2013 June 3. Following this discovery, we planned observations of several occultations by Chariklo's system in order to better characterize the physical properties of the ring and main body. Here, we use 12 successful occulations by Chariklo observed between 2014 and 2016. They provide ring profiles (physical width, opacity, edge structure) and constraints on the radii and pole position. Our new observations are currently consistent with the circular ring solution and pole position, to within the $\pm 3.3$ km formal uncertainty for the ring radii derived by Braga-Ribas et al. The six resolved C1R profiles reveal significant width variations from $\sim 5$ to 7.5 km. The width of the fainter ring C2R is less constrained, and may vary between 0.1 and 1 km. The inner and outer edges of C1R are consistent with infinitely sharp boundaries, with typical upper limits of one kilometer for the transition zone between the ring and empty space. No constraint on the sharpness of C2R's edges is available. A 1$\sigma$ upper limit of $\sim 20$ m is derived for the equivalent width of narrow (physical width <4 km) rings up to distances of 12,000 km, counted in the ring plane

Size and Shape of Chariklo from Multi-epoch Stellar Occultation

We use data from five stellar occultations observed between 2013 and 2016 to constrain Chariklo’s size and shape, and the ring reflectivity. We consider four possible models for Chariklo (sphere, Maclaurin spheroid, triaxial ellipsoid, and Jacobi ellipsoid), and we use a Bayesian approach to estimate the corresponding parameters. The spherical model has a radius R = 129 ± 3 km. The Maclaurin model has equatorial and polar radii a=b={143}-6+3 {km} and c={96}-4+14 {km}, respectively, with density {970}-180+300 {kg} {{{m}}}-3. The ellipsoidal model has semiaxes a={148}-4+6 {km}, b={132}-5+6 {km}, and c={102}-8+10 {km}. Finally, the Jacobi model has semiaxes a = 157 ± 4 km, b = 139 ± 4 km, and c = 86 ± 1 km, and density {796}-4+2 {kg} {{{m}}}-3. Depending on the model, we obtain topographic features of 6–11 km, typical of Saturn icy satellites with similar size and density. We constrain Chariklo’s geometric albedo between 3.1% (sphere) and 4.9% (ellipsoid), while the ring I/F reflectivity is less constrained between 0.6% (Jacobi) and 8.9% (sphere). The ellipsoid model explains both the optical light curve and the long-term photometry variation of the system, giving a plausible value for the geometric albedo of the ring particles of 10%–15%. The derived mass of Chariklo of 6–8 × 1018 kg places the rings close to 3:1 resonance between the ring mean motion and Chariklo’s rotation period

Stakeholder Relations and Ownership of a Community Wireless Network: The Case of iNethi

The primary objective for this study is to investigate multi-stakeholder understanding of ownership of a community wireless network (CWN) located in Ocean View, Cape Town. This is important because ownership and stakeholder relations are components that contribute to the success of a CWN. Using the convenience and snowball sampling method, we completed 11 semi-structured interviews with stakeholders from the University of Cape Town and the Ocean View community. We consider different ways ownership is conceived between stakeholders. We found that the involvement of the community at initiation of a CWN project is imperative in establishing ownership of a CWN. We characterize some of the ways in which discordant conceptions of ownership have resulted in miscommunication within this project and offer considerations for researchers to take into account as they collaborate with communities on joint initiatives

The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package

The Astropy project supports and fosters the development of open-source and openly-developed Python packages that provide commonly-needed functionality to the astronomical community. A key element of the Astropy project is the core package Astropy, which serves as the foundation for more specialized projects and packages. In this article, we provide an overview of the organization of the Astropy project and summarize key features in the core package as of the recent major release, version 2.0. We then describe the project infrastructure designed to facilitate and support development for a broader ecosystem of inter-operable packages. We conclude with a future outlook of planned new features and directions for the broader Astropy project