Supernova 1972 e in NGC 5253

New absolute energy distributions of the Type 1 supernova 1972e in NGC 5253 extending to about 700 days after maximum light were obtained. A physical model of the expanding envelope, based on the identification of the feature at 6550 A with H-alpha, is proposed. It is described as a differentially expanding atmosphere, with electron density ranging from 10 to the 10th power near maximum light to about 10 to the 7th power, 340 days later, illuminated by a photosphere with temperature in the range 10,000 K to 7,000 K. More than 200 days after maximum, the spectrum was dominated by four features between 4200 A and 5500 A. Three of these four features matched the blended emissions from over 100 lines of Fe II. Possible identifications of the fourth feature with Mg I lambda 4571 or permitted lines of Fe II are also discussed

Radial distribution of Fe XIV emission in the Cygnus Loop

The one dimensional distribution of Fe 14 emission has been determined along a radius of the Cygnus Loop through the use of a tilting filter photometer. The observed emission extends at least 5 arc minutes outside the optical filaments. A simple Sedov solution model of the temperature and density distribution behind the shock agrees with the observations if the shock front is near the extent of the Fe 14 emission, the shock velocity is from 300 to 250/kms and the density external to the remnant is about 0.7-1.4 cm to three minus 3 power. These parameters are in reasonable agreement with X-ray maps and optical radial velocities

Mining and extractive urbanism: Postdevelopment in a Mozambican boomtown

Mozambique has attracted international attention in recent years following the discovery of huge reserves of coal and gas deposits. A major focus of Mozambique’s extractives boom is the province of Tete, once a remote outpost but now a hub of power generation for the southern African region and an emerging centre of global investment in coal extraction. Some of the world’s largest mining firms from both established and emerging economies have descended on Tete, investing billions of dollars in developing concessions to extract some of the world’s largest untapped coal reserves with wide-ranging implications for the region’s political economy and effecting significant shifts in relations between state, capital and territorial control. At the urban scale, Tete city and its expanding periphery are increasingly characterised by enclaves and spaces of enclosure, as some groups benefit from and are integrated into global circuits of production whilst others suffer displacement and dispossession. In seeking to trace the emergence of Tete’s resource economy, the paper contends that three distinctive spatialities have resulted from these developments, including the infrastructure networks being constructed around the extractive industries, the enclave spaces arising from the coal boom (and the particular labour geographies that shape them) and the new and distinctive urban geographies that are the product of Tete’s rapid urbanisation. The paper seeks to assess the impacts, stakes and challenges linked to investments in extractive activities and looks at how the costs and risks are being differentially distributed within and between the affected communities

Formulae for Growth Factors In Expanding Universes Containing Matter and a Cosmological Constant

Formulae are presented for the linear growth factor D/a and its logarithmic derivative dlnD/dlna in expanding Friedmann-Robertson-Walker Universes with arbitrary matter and vacuum densities. The formulae permit rapid and stable numerical evaluation. A fortran program is available at http://casa.colorado.edu/~ajsh/growl/ .Comment: 7 pages, including 3 embedded PostScript figures. Minor changes to agree with version accepted for publication in MNRAS. Fortran package growl.tar.gz available at http://casa.colorado.edu/~ajsh/growl

A New Sub-Period-Minimum Cataclysmic Variable With Partial Hydrogen Depletion And Evidence Of Spiral Disk Structure

We present time-resolved spectroscopy and photometry of CSS 120422:111127+571239 (=SBS 1108+574), a recently discovered SU UMa-type dwarf nova whose 55 minute orbital period is well below the cataclysmic variable (CV) period minimum of similar to 78 minutes. In contrast with most other known CVs, its spectrum features He I emission of comparable strength to the Balmer lines, implying a hydrogen abundance less than 0.1 of long-period CVs-but still at least 10 times higher than that in AM CVn stars. Together, the short orbital period and remarkable helium-to-hydrogen ratio suggest that mass transfer in CSS 120422 began near the end of the donor star's main-sequence lifetime, meaning that this CV is a strong candidate progenitor of an AM CVn system as described by Podsiadlowski et al. Moreover, a Doppler tomogram of the Ha line reveals two distinct regions of enhanced emission. While one is the result of the stream-disk impact, the other is probably attributable to spiral disk structure generated when material in the outer disk achieves a 2:1 orbital resonance with respect to the donor.NSF AST-1211196, AST-9987045Department of Physics at the University of Notre DameNSF Telescope System Instrumentation Program (TSIP)Ohio Board of RegentsOhio State University Office of ResearchAstronom