ABSTRACT
In this study of the physics of stars and their astronomical identification, it is evident that stars undergo certain physical processes as they live through their life cycle. How gravity, magnetic field and nuclear fusion play a role in stellar evolution is explained extensively. This research describes the structure and evolution of stars. The structure and evolution of a star is determined by the laws of Hydrostatic equilibrium, energy transport and generation and conservation of energy while the mass of the star is the governing factor in the evolution and structure of the star and determines its properties. Also, stellar spectra is discussed in this work. Different elements absorb different wavelengths of light. The spectrum of a star lets us know what elements are in the star. Finally, stars and how they are identified astronomically is also discussed as different stars have different astronomical identification. This paper uses established techniques in cultural astronomy to identify seasonal stars in the traditions of the Kaurna Aboriginal people of the Adelaide Plains, South Australia.
CHAPTER ONE
INTRODUCTION
In the astronomical traditions of Aboriginal Australians, the rising and setting of particular stars at dusk and dawn are used as calendric markers, noting the changing of seasons, the availability of food sources, and the breeding cycles of animals (Clarke, 2007; Hamacher, 2012; Johnson, 1998; Tindale, 1983). Some calendric stars are described in Aboriginal traditions but their identity is often unclear, in part because of misidentifications (e.g. Howitt, 1884a: 198).
The Adelaide Plains of South Australia are the traditional lands of the Kaurna1 people (Figure 1). Much of their culture was damaged by colonisation, particularly from 1836 onwards (Manning, 2002). Kaurna astronomical traditions are not well recorded, as the Kaurna “carefully conceal them [astronomical traditions] from Europeans, and even their own males are only at a certain age initiated into the knowledge of them,” (Teichelmann, 1841).
What we do know about Kaurna language comes predominantly from the records of the German Lutheran missionaries Christian Gottlieb Teichelmann (1807-1888) and Clamor Wilhelm Schürmann (1815-1893), who came to Adelaide on October 1838. In 1840, they published a dictionary of 2,000 Kaurna words (Teichelmann and Schürmann, 1840). Much of the Kaurna language was provided by local Aboriginal men, including Mullawirraburka (aka King John) and Kadlitpinna (aka Captain Jack), (Amery, 2000: 56).
Teichelmann continued working on the Kaurna language, compiling a manuscript of Kaurna vocabulary and grammatical notes (Teichelmann, 1857). Clarke (1990, 1997) published research on Kaurna astronomical traditions, but the identity of many of the stars remains a mystery.
We do know that in Kaurna traditions, particular stars govern seasons. For example, autumn (Parnatti) is signaled by the morning appearance of the star Parna. This warns the Kaurna that the annual autumn rains will soon arrive and that they need to build large, waterproof huts (Teichelmann and Schürmann, 1840).
Figure 1: Left: The traditional lands of the Kaurna people, South Australia, stretching from Adelaide in the south to Port Broughton in the north. Adelaide CBD in red, greater city in orange, and metropolitan area in yellow. Image: Wikipedia Commons license. Right: Topographic map showing the extent of the Adelaide Plains, following the Kaurna lands closely (green indicates low elevation areas while red/pink indicate higher elevation). Image: topographic-map.com.
Sun is an average star of spectral type having absolute magnitude4.8 and falls in the middle of the main sequence, Because of its close proximity to the earth, Sun's image can be projected and a resolvable disk of high intensity makes it easier to study the solar structure in great detail which is not possible for other stars. Hence, Sun is the only star whose physics we can probe. Stars on the main sequence are those that have interior structures quite similar to the Sun. These stars must have great central pressures to hold up the enormous weight of their envelopes, and this central pressure yields a high central temperature. Thanks to the high central temperature, nuclear reactions proceed in the cores of these stars and they become hot and luminous. Direct observations of the interior of the Sun is not possible and most of the information available concerning the core of the Sun are based on hypothetical conclusions arrived from studying the surface and outer atmospheric features. It has been suggested that Sun and other stars may still have rapidly spinning cores left over from the time of formation. Also the structure of the outer layers is modified by the existence of convection, which is difficult to model. There has been renewed interest in solar interior because we can now probe it by solar seismology and neutrino observations. Sun is the only star for which such observations are possible and these observations have greater importance for understanding the physical processes of other stars.
AIM OF THE STUDY
This study is aimed at examining and understanding the physics of stars and their astronomical identification.
SIGNIFICANCE OF THE STUDY
A scientist is a consumer as well as producer of information as he/she acquires, manipulates, updates, improves and report information. Consequently adequate understanding of the information gotten from the study is necessary for the proper planning and improving of further research in this setting. There are several studies that concentrates on the specific subjects or fields in the area. The study of the physics of stars and their astronomical identification especially in developing countries has been a significant and eventful issue from last few decades. Therefore, knowledge about the information needs and seeking behavior of users could play a vital role in meeting their information needs effectively.
