Kepler Observations of V447 Lyr: An Eclipsing U Gem Cataclysmic Variable

We present the results of an analysis of data covering 1.5 years of the dwarf nova V447 Lyr. We detect eclipses of the accretion disk by the mass donating secondary star every 3.74 hrs which is the binary orbital period. V447 Lyr is therefore the first dwarf nova in the Kepler field to show eclipses. We also detect five long outbursts and six short outbursts showing V447 Lyr is a U Gem type dwarf nova. We show that the orbital phase of the mid-eclipse occurs earlier during outbursts compared to quiescence and that the width of the eclipse is greater during outburst. This suggests that the bright spot is more prominent during quiescence and that the disk is larger during outburst than quiescence. This is consistent with an expansion of the outer disk radius due to the presence of high viscosity material associated with the outburst, followed by a contraction in quiescence due to the accretion of low angular momentum material. We note that the long outbursts appear to be triggered by a short outburst, which is also observed in the super-outbursts of SU UMa dwarf novae as observed using Kepler.Comment: Accepted by MNRA

V344 Lyrae: A Touchstone SU UMa Cataclysmic Variable in the Kepler Field

We report on the analysis of the Kepler short-cadence (SC) light curve of V344 Lyr obtained during 2009 June 20 through 2010 Mar 19 (Q2--Q4). The system is an SU UMa star showing dwarf nova outbursts and superoutbursts, and promises to be a touchstone for CV studies for the foreseeable future. The system displays both positive and negative superhumps with periods of 2.20 and 2.06-hr, respectively, and we identify an orbital period of 2.11-hr. The positive superhumps have a maximum amplitude of ~0.25-mag, the negative superhumps a maximum amplitude of ~0.8 mag, and the orbital period at quiescence has an amplitude of ~0.025 mag. The quality of the Kepler data is such that we can test vigorously the models for accretion disk dynamics that have been emerging in the past several years. The SC data for V344 Lyr are consistent with the model that two physical sources yield positive superhumps: early in the superoutburst, the superhump signal is generated by viscous dissipation within the periodically flexing disk, but late in the superoutburst, the signal is generated as the accretion stream bright spot sweeps around the rim of the non-axisymmetric disk. The disk superhumps are roughly anti-phased with the stream/late superhumps. The V344 Lyr data also reveal negative superhumps arising from accretion onto a tilted disk precessing in the retrograde direction, and suggest that negative superhumps may appear during the decline of DN outbursts. The period of negative superhumps has a positive dP/dt in between outbursts.Comment: ApJ, In Press (20 pages, 27 figures) A version with full-resolution figures is available at http://www.astro.fit.edu/wood/WoodV344.pd

Recognizing Poverty Rules: Addressing the Causes and Patterns of Absolute Poverty among the Makua-Metto People

Drawing on qualitative interviews with the Makua-Metto people of Mozambique, the author develops a curriculum addressing the topic of poverty. The contextualized approach considers poverty as a system and makes use of local solutions. The article includes a diagram illustrating the causes of poverty and two series of narratives linked by the metaphor of games to demonstrate Makua-Metto behavioral norms of people in poverty and those living free from its deepest effects

Swapping Drinking Songs for Spiritual Songs: Skolia and Possession in Ephesians 5 and Mozambique

The prevalence of both drinking songs and spirit possession among the Makua-Metto of Mozambique shaped the way in which Mozambican Christians interpreted Paul’s letter to the Ephesians. Based upon their cultural context, they naturally heard chapter 5 addressing these two phenomena as interconnected topics. That experience led to an investigation into the background of the original recipients of the letter through the lens of drinking songs and spirit possession to see if reading this text in the “laboratory” of the Mozambican context can shed new light on contemporary readings of the Ephesian 5 text and provide an example of non-Western contextual interpretation