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Beech M.,Campion College at the University of Regina
Observatory | Year: 2011

A brief overview of the α Centauri system is presented and the possibility that planets and a cometary can be formed about α Cen AB is considered. The rotational and flare-activity characteristics of Proxima Centauri is also reviewed. The impact hypothesis is revisited to determine if the flare activity associated with Proxima will be explained or modulated through planetesimal accretion. The use of Oort Cloud characteristics as an analogue reveals that the impact rate on Proxima is low to account for its overall flare activity. It is also revealed that the Proxima needs to reside just 15000 AU from α Cen AB, while the possibility of such an arrangement coming about purely by chance are about I in 57000. Source


Beech M.,Campion College at the University of Regina
Astrophysics and Space Science | Year: 2011

A brief review of the threat posed to Earth's biosphere via near-by supernova detonations is presented. The expected radiation dosage, cosmic ray flux and expanding blast wave collision effects are considered, and it is argued that a typical supernova must be closer than ~10-pc before any appreciable and potentially harmful atmosphere/biosphere effects are likely to occur. In contrast, the critical distance for Gamma-ray bursts is of order 1-kpc. In spite of the high energy effects potentially involved, the geological record provides no clear-cut evidence for any historic supernova induced mass extinctions and/or strong climate change episodes. This, however, is mostly a reflection of their being numerous possible (terrestrial and astronomical) forcing mechanisms acting upon the biosphere and the difficulty of distinguishing between competing scenarios. Key to resolving this situation, it is suggested, is the development of supernova specific extinction and climate change linked ecological models. Moving to the future, we estimate that over the remaining lifetime of the biosphere (~2 Gyr) the Earth might experience 1 GRB and 20 supernova detonations within their respective harmful threat ranges. There are currently at least 12 potential pre-supernova systems within 1-kpc of the Sun. Of these systems IK Pegasi is the closest Type Ia pre-supernova candidate and Betelgeuse is the closest potential Type II supernova candidate. We review in some detail the past, present and future behavior of these two systems. Developing a detailed evolutionary model we find that IK Pegasi will likely not detonate until some 1.9 billion years hence, and that it affords absolutely no threat to Earth's biosphere. Betelgeuse is the closest, reasonably well understood, pre-supernova candidate to the Sun at the present epoch, and may undergo detonation any time within the next several million years. The stand-off distance of Betelgeuse at the time of its detonation is estimated to fall between 150 and 300-pc-again, affording no possible threat to Earth's biosphere. Temporally, the next most likely, close, potential Type Ic supernova to the Sun is the Wolf-Rayet star within the γ2 Velorum binary system located at least 260-pc away. It is suggested that evidence relating to large-scale astroengineering projects might fruitfully be looked for in those regions located within 10 to 30-pc of any pre-supernova candidate system. © 2011 Springer Science+Business Media B.V. Source


Beech M.,Campion College at the University of Regina
Astronomy and Geophysics | Year: 2012

Martin Beech looks at the history of scientific interest in our nearest star system, ± Centauri, and the recent surge in research that has resulted in the discovery of our nearest exoplanet. © 2012 Royal Astronomical Society. Source


Beech M.,Campion College at the University of Regina
Monthly Notices of the Royal Astronomical Society | Year: 2010

We investigate the heating of micrometeorites and dust particles, as they decelerate in the Earth's upper atmosphere, when finite-size correction effects to the Stefan-Boltzmann surface reradiation law apply. For particles smaller than about 25 μm across, it is found that the finite-size corrections result in significantly lower maximum temperatures being realized. Indeed, the finite-size correction to the Stefan-Boltzmann law acts in the opposite sense to that of a reduced radiative efficiency which tends to increase the temperature of small meteoroids. It is also found that the accumulated thermal processing during atmospheric deceleration is greatly reduced when finite-size correction effects become important and this may have important consequences for the loss of volatile elements, as well as any petrographic alterations that a dust particle may experience. © 2009 The Author. Journal compilation © 2009 RAS. Source


Arbuthnott K.D.,Campion College at the University of Regina
Analyses of Social Issues and Public Policy | Year: 2012

Markowitz and Bowerman's (2011) observation that a large majority of Oregon citizens support reduced consumption is heartening, and is a good basis for their suggestion that public policy be directed at the issue of consumption. However, evidence of weak correlations between self-reported intentions and observed behaviors indicates that reducing actual consumption will be effortful, despite favorable attitudes. Two particular barriers to the transition from attitude to action, habits, and psychological needs are discussed, and it is suggested that evidence of association between well-being and reduced consumption could provide more specific direction for public actions. © 2011 The Society for the Psychological Study of Social Issues. Source

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